Sealing Slate Tile Floors Installation Servies – TheFlooringlady

To seal, or not to seal, that is the question. If you are about to install a slate floor, you have probably heard conflicting opinions about sealing your tiles.

The conflicting advice comes from the different experiences contractors and homeowners have had with slate tiles.

Different experiences come from using different types of slate. Sealing slate isn't necessary, especially if you want to keep the natural look and beauty of the slate.

However, if the stone is porous and/or you aren't experienced at grouting, seal the stone first.

 Furthermore, sealing slate is important if you want a shiny or matte finish, and if you want to protect it from staining.

You can buy chemical sealers at retail stone and home improvement stores.

Best Sealer for Your Slate Floor!

To help maintain better air quality, you want to use a water-based polyurethane sealer.

To help give the stone its best protection, a penetrating sealer is a good precaution. 

In addition to being low in VOCs (volatile organic compounds), water-based polyurethane is non-yellowing and non-cracking, giving you years of good looking slate floor tiles.

 The BulletProof Sealer by StoneTech and 511 Impregnator Sealer by Miracle Sealants are popular choices for water-based sealers.

Slate Varieties for Your Home

Slate typically comes from Brazil, Vermont, China and India.

The Brazilian and Vermont slates tend to have a low absorption rate, while Indian and Chinese have variable absorption rates. 

The softer slates need more attention with sealants before and after installation than do the harder slate tiles. Slate is a metamorphic rock, starting as a sedimentary rock and with pressure and temperature over time became slate.

It is made of materials with characteristics like clay, and it has a structure similar to layers of sheets.

Because it has some porosity, you may want to seal it to keep it from staining and soiling.

Brazilian slate

Indian slate

Chinese Slate

A bit more about the origin of your slate will help you determine how you want to treat it. Brazilian slate is typically dense and has variegated colors while Vermont slate is typically dense, smooth and one consistent color (black, blue, green red).

In contrast, Chinese and Indian slates are typically variable in density (soft to hard) and variegated coloring, with a wide range of colors.

 If you get a soft slate, typically Chinese or Indian, pre-seal with a porous stone sealer.

​Step 1: Preparation

The preparation needed before installing your slate floor tiles is to clean the subfloor where the slate is to be installed.

Clean dust and dirt from all slate surfaces, and let them dry thoroughly before applying two coats of the penetrating tile sealer.

Step 2: Application

There are surface, or topical, sealers, but the penetrating sealer gives your stone tile better protection, and looks better longer.

Apply the sealer in a thin coat using a sprayer, roller or brush, following the grain of the slate and let it dry for at least two hours and reapply (your specific product will tell you how long between coats to let it dry).

Step 3: Grouting

After you have laid the tiles, let the mortar dry and cure before grouting the tiles.

To increase the bonding strength of your mortar and grout, mix penetrating sealant with grout instead of water.

This recipe increases bond and tensile strengths and improves the water resistance of the installation.

The increased water resistance is especially important if you are installing your slate tile floor on a concrete slab that can wick ground moisture into the room.

Step 4: Finishing

What look do you want your slate floor to have -- natural, wet, or glossy? You can get the wet-look without going to glossy by choosing the right finish.

There are finishes that will look natural after application, but many people love the wet-look for their slate floor. Black Diamond Stone Works offers such a sealer with a high gloss finish.

 If you want to enhance the color of your slate without making it look too glossy, you could go for the Stone Enhancer by Auqamix.

Step 5: Washing and Cleaning

After you grout the tiles (preferably with latex grout because it increases flex strength, reduces efflorescence, and has great bond strength), let it dry, ideally for a week, before cleaning the tiles.

You want to wash the tiles thoroughly, several times, to remove all remnants of excess grout so that it won't become a permanent part of your slate floor.

Step 6: Recoating

When the tiles are dry from the washing, you can apply two more coats of penetrating sealant.

 This step is to add further protection to the slate, but also to the grout and grout-tile interface.

Step 7: Curing

After you have applied your last coat of penetrating slate tile sealant, let cure for at least 24 hours before walking on the floor.

The longer you can let it cure before walking on it, the better protection you will have, and the longer the finish will last. 

Note that the sealer needs to be re-applied after every 3 to 5 years for interior surfaces, and every 1 to 3 years for exterior surfaces, depending on the brand.

 To have a better idea on how to reseal slate surfaces, check out this video:

Caring for Slate Floors

Compared to ceramic tiles, maintaining your slate floor requires extra care. Like any object, slate tiles will age faster if neglected.

  • For a start, you need to clean it regularly if you want it to look good after many years. Wash it with mild soap and water, and dry mop or vacuum in between washings. This will remove dust and dirt, which is the main cause of scratches on most surfaces. When mopping, move in one direction instead of back and forth. Let the dust accumulate in one spit and them collect them using a dustpan.
  • When the mop is not in use, store it properly with the head off the floor.
  • It is recommended that you mop your slate floor with a damp mop at least once a week.
  • As an added protection, place a welcome mat or rug at the door. Or better yet, have room slippers ready for your household and visitors, so they can leave their shoes at the door.

Regular Cleaning and Maintenance

Highly acidic or alkaline cleaning solutions can reduce the effectivity of your sealer. It’s best to use a cleaner that is neutral, formulated specially for stones, and if possible, matches with the brand of your sealer.

The usual solution is to mix 1 part solution to 4 parts water, but you can also mix 1 part solution to 1 part water when cleaning darker stains. Clean the surface before application.

Use a sprayer, mop, sponge or scrub when applying. Some solutions won’t require rinsing after, while others will.

If you are accustomed to waxing floors, you are in for a treat because wax isn't necessary on slate.

Wax won't hurt the slate, but will obscure it's natural beauty, turn the tiles a darker shade, and may yellow the grout; all good reasons to not wax your floor.

Step 1: Identify original coating

To find out what coating was originally applied, mix one cup of ammonia with one gallon of water.

 Apply it on the floor, scrub it then wipe off. If the coating was removed, most likely wax has been use. If the coating wasn’t removed, then there’s a chance that it is urethane or epoxy based and harder to strip off.

Step 2: Removal of wax or Water based coating

  1. Mix the product in a bucket according to manufacturer instructions.
  2. Apply the mixture in a small area where you can cover scrubbing until it dries.
  3. Let the solution stay for a few minutes and then add more so it stays wet.
  4. Scrub the floor using a buffer or you can do it manually with a scrubbing pad that has just the right hardness.
  5. Rinse the solution thoroughly with water.

Step 3: Removing Urethane or Epoxy Based Coatings

When removing urethane or epoxy-based coatings, you need a strong solvent-based stripping solution. Practice safety measures by wearing mask and goggles when applying.

Also ensure that there’s proper ventilation and that you won’t disturb the neighbors. If you don’t feel confident about handling a dangerous chemical, you can always contact a professional to do it for you.

  1. Apply the solution with a brush or roller and let it sit for a few hours.
  2. Then try stripping off the coating with a putty knife.
  3. If it comes off easily, it means that the solution has taken effect and you can already strip off the coating.
  4. After this, you would need to apply the alkaline stripper.


Slate makes a beautiful flooring. Proper preparation and care of it will keep it looking great for years to come.

If you can't decide if you should seal your new slate tiles before installing them, error on the side of caution. 

Sealing them may not be necessary, but after you have installed them it will be a headache to seal them properly. 

And you may not be able to protect them soon enough, if they are porous and absorb stains.

To seal or not to seal?

Go for it with a penetrating, water-based slate tile sealer and enjoy your natural stone floor for years.

420 thoughts on “Sealing Slate Tile Floors Installation Servies – TheFlooringlady

  1. I high sheen finish will take care of providing a wet look on slate, brick, wood, or even concrete.
    But from personal experience, a high-sheen floor finish also shows dust much more than a low-sheen floor finish. That’s especially true if the floor is dark — like black slate.
    From my personal perspective, the beauty of slate and other stone floorings is the look of the stone. When it’s sealed with a high-sheen finish, it looks fake to me, detracting from the natural beauty of the stone.
    That said, there can be lots of reasons to have a high-sheen finish on slate floors. Be sure to clean the surface well so the sealant doesn’t lift later.
    – The Flooring Lady

  2. Hi we are in the process of installing slate tiles in an outdoor walkway. The installer bought 511 Impregnator. He said the slate needs 1 coat on the bad side that will face the ground and 3 coats on the good side. I love the way it looks when wet but I am not as attracted to it when it dries. We have only applied the 511 Impregnator on the bad side, and have not applied it on the good side yet. What should I do? Should we apply the 511 Impregnator on the good side then get a wet sealer and apply over? Or if I want the wet look should i not apply the 511 Impregnator and only apply a wet sealer? I am confused on this process. I live in Northern California and only have Home Depot to get products, does anyone know of a good product to get a semi gloss look? Thanks!!

  3. I am about to install Indian Slate Rock tiles in my kitchen. I have heard that it is better to seal it first to prevent the grout from staining the slate rock. Would you advise against using a xylene based paver/stone sealer?

  4. I personally would advise strongly against using xylene-based products. Xylene has been associated with various health problems, and I strive for healthy environments, which start with the materials you use indoors.
    Check with your flooring company to see what sealant alternatives they have for you. To avoid health problems, avoid using xylene.

  5. I’ve never heard of using oils like that to seal slate. And the use of linseed oil for sealing wood is often discouraged because it encourages mold/mildew growth on the wood. I’d think they would not be the right products to use on a slate floor, or any floor for that matter.

  6. I am also getting ready to install a slate floor on my front porch. While covered, it does get wet during a heavy Florida rain. I like the wet look to bring out the most color, but I also do not want the tile to be slippery when wet. Will the sealers make the tile more slippery?

  7. As long as you don’t apply thick layers of sealant, you should be fine. If you apply two light coats, allowing them to dry completely between applications, you should enjoy the wet look without a slippery treachery.
    The key is to not build a heavy layer on the surface, letting the natural texture of the Saltillo tile through. Make sure there is no remaining old sealer present on the surface before you apply the new product you’ll have good results too.
    Test a small area first, preferably on scrap of tile or in an out-of-the-way spot, to see end results prior to completing entire project.

  8. I have old slate floors that are in good condition but never sealed. Want to seal them with a matte finish but they also need to be cleaned first. What should I do?

  9. Just installed beautiful green slate floor-a uniform color. Sealed as explained on bottle of $40 sealant and floor dried with some blotchy spots. It looks as if baby oil or olive oil fell on those spots (it didn’t.) We let the floor dry thouroly before walking on it.
    My contractor is mystified.
    Do we strip off the sealant and start again? (Strip how??)
    Or should we apply another layer of the sealant??
    Thanks for your advice.

  10. Hi,
    We put a sealant down a few times on our slate floor and the sealant just doesn’t seem to last. It fades and the floor goes back to looking “dirty and blah”. We decided to put down some transeal (clear gloss varnish to give it a lasting shiny poly finish), however, it looks like it may be beading because of the sealant we previously put down. Do we need to remove the sealant first before applying transeal ? If so, how do you recommend removing the sealant?
    Thanks so much,

  11. Stone flooring needs to be cleaned carefully before sealing it for the first time. Carefully means using the cleaner that won’t harm the stone. For example, vinegar on a sandstone floor could cause damage. Before you use any cleaner on your stone, check it out in an inconspicuous area first.
    Regular sweeping/vacuuming and damp mopping will keep a stone floor in good shape longer than when you let the grit and grime build up.
    If you need to reseal a stone/brick/tile floor — and they do need annual resealing, if you go with the same product you used initially just reapply the product. But if you are changing sealing products, check the compatibility of the new and old sealants by testing in an inconspicuous area. You may need to strip the old sealant off before applying a new sealant. Ask your flooring manufacturer, installer, or the store where you bought your flooring product for suggestions of how to best remove the old sealant.
    If you find spots appearing on the tile after you’ve sealed it, chances are some chemical got into the stone before you sealed it, even before you bought it. Extracting it could be challenging because it may have become part of the stone makeup.

  12. I had a slate flor laid and sealed, but the tiles still look slightly white as if dusty in parts. Is this natural or do i need to unseal,clean and re-seal? Thanks

  13. The white haze is not natural. You may not need to completely remove the sealant that’s there; you may need to thin it.
    The haze could be caused by several things. It could be the use of a water-based sealant that’s not formulated for slate floors, in which case you probably do need to remove it and start again.
    It could be that too much sealant was applied, the coats after the first are pooled and giving the white haze look. In this case you could use a white buffing pad under a regular rotary machine.
    Don’t hesitate to ask the manufacturer of your slate for input either.

  14. I don’t have personal experience with Indian slate outdoors. My best guess, from what I do know about slate, is you should seal it before installing it so you don’t get it absorbing moisture and minerals from your soil.
    But do check with the manufacturer/provider to see what they say and learn about their warranty.

  15. Just wondering if you can use any floor cleaner (ie: Mr. Clean, PineSol, Swiffer, etc) for regular cleaning of slate tile floor?

  16. I’m sure the manufacturers of those products would say you can use them with no problem, but I’d think they might be too strong for the slate, especially if the slate hasn’t been sealed. For air quality reasons I’d say avoid those products too.
    But of the products you mentioned, Mr Clean would be the one I’m most suspicious of being too strong. I personally would use a vinegar water solution on the floor — a 1:10 vinegar:water solution — to clean my floors with.

    • Ummmm, you keep saying do NOT use a vinegar solution to clean slate floors, but you just suggested using vinegar! ? I know it’s a very diluted solution – 1 part vinegar to 10 parts water – but that seems contradictory. ? Also, we are renting a home with slate flooring and don’t know what was previously used, or if the floors were sealed. (I’m assuming they were.) Landlord doesn’t know either. I physically cannot be on my hands/knees to strip, clean, seal the floors. Neither can the new Mom with a 1 week old baby. Are we doomed to hiring a professional?

  17. My flooring installer is currently preparing to install a copper quartzite floor in my home. I understand quartzite is similar to slate. This stone has an irridescent metallic look to it,expecially when wet, and depth, like you’re looking into a canyon. I would like to maximize the ability to see those features after sealing. Any suggestions?

  18. Your flooring choice sounds wonderfully beautiful. Quartzite is similar to slate only in that they are both metamorphic rocks. Quartzite started as limestone while slate started as shale. Rocks that have textured surfaces with clefts are called slates, but the texture isn’t what makes it a slate. Quartzite has a MOH’s scale of 7, making it a wonderfully hard rock and good floor.
    You need to test a sample piece of stone with a sealant formulated for quartz flooring to see if it creates the sheen you are seeking, even after its dry. I’m not sure what the best approach is going to be since I don’t have personal experience with that particular floor.
    We’d love to find out what you end up doing and how you like the floor once it’s installed and used.

  19. Recently had slate tiles installed in bathroom. Installer suggested 511 sealer but did not seal until completely installed. 80% of tiles have bevel look where grout went in about 1 inch around the entire 16×16 slate.
    Should we have sealed first / then layed/ then grouted to elimintate grout seaping into pourous slate?

  20. Loose tiles everywhere:
    We had a slate floor installed 2 years ago (Dark Grey Slate 24″x24″, natural finish — i.e. not honed). It was installed on an existing concrete floor that was 4 years old which previously had hardwoods glued to it. The installers had a devil of a time getting rid of the old wood floors because of the glue, etc, but finally did it.
    They installed the new slate directly onto the concrete floors (they were relatively clean) but to level the floor a lot of thinset was used (and in some cases additional concrete) to build up the old surface to make it level.
    Starting immediately and now two years later, about 50 of the nearly 350 tiles are loose. They sound hollow when walked on, are noticeably loose in some cases, and the grout is cracking and chipping away (in some cases getting lodged underneath the tiles, lifting them up and making them crack). They make crunching sounds when you walk on some of them as well.
    We removed two tiles to see what happened and it appears that the concrete/mortar stuck to the slate just fine but not to the original concrete floor. We have ordered replacement tiles, but don’t want to re-install improperly.
    What would be the proper way to install slate tiles to an existing (interior) concrete floor? I’ve read about some adhesive between the old concrete and new concrete? Should we use concrete backerboard instead which is adhered to the concrete via cement nails or screws?

  21. I have recently finished laying a 9′ x 16′ slate floor in my dining room and would like to keep the wet look that we saw when we were washing them. What would be the best way to seal them and still keep that wet look?

  22. Regarding tiling over old interior concrete, it would seem there does need to be some prep work to do to let the mastic adhere to the concrete. How clean was the concrete slab before applying the mastic? If it hadn’t been cleaned of oil, stains, dirt, etc, the mastic couldn’t adhere to it.
    The problem with using backerboard is that it will change your flooring level. That may not be a concern, but it’s something to pay attention to.
    It sounds as if you need to remove all of your tiles, clean the concrete, and start again.
    Let us know what you did and how it turned out.

  23. We have just moved into a house which has black slate floors to all the wet areas. Unfortunately the slate looks disgusting at the moment and we are not sure how to ressurect it back to its former glory.
    The slate looks as though it has some grout stains on it but in some sections it also looks as though the sealer is coming off ie. shiny in some sections and dull in others.
    Can you recommend how to fix this problem? Do you recommend re-sealing and if so, what do I do first to remove all the marks and old sealer?
    Much appreciated.

  24. I have a slate tile hearth and I can see that it was sealed at some point in its life (81 year old house). Today the slate looks very faded and dusty even after cleaning. I am thinking that I should find some way to strip the old sealer and reapply before we get our new fireplace! Do you have any advice on stripping or any recommendations for sealing existing installations?

  25. My installer laid down all the slate and grouted it and it looked great. We then chose a sealer that was supposed to seal and make a low sheen, darker finish. It has been 36 hours and the sealer is a wet and slimy as when it went down. What could be wrong here? We have A/C and low humid conditions.

  26. My first reaction is the tiles already had a sealant and they two are reacting against each other. But the product could have been applied incorrectly or be defective itself. I think you need to get a local person over there to check it out, along with looking at the product label.

  27. I am planning to install indian slate tiles in my kitchen over 3/4 inch plywood over 3/4 inch osb over 2 x 12 joists 16 on center. I will be using thin set mortar. Do I need to seal top and bottom of tiles or just top before install? thanks Carla

  28. I have been convinced by someone who deals with slate floors a lot that using one thick coat of sealant is better than two lighter coats. And that sealant can interfere with the adherence of grout.
    My conclusion is that sealing the slate after installation allows you to pour the sealant on the floor so it can soak in as needed by each bit of stone and then move it to the next area, pour on more sealant and keep working across the floor in that manner.
    Sealing slate is to protect it from absorbing grease- and water-based liquids and creating stains. Those issues aren’t a problem on the bottom side of slate flooring. I don’t see that you need to seal the bottom surface of your Indian slate.

  29. We just finished doing our backyard in our new home in the San Ramon, CA. We used a combination of Indian slate and stamped concrete on the walkable surfaces.
    We had our contractor apply a sealant on the slate as well as stamped concrete after he showed us pictures of how it looks after the sealant is applied.
    To our dismay, we found out that the sealant has made our backyard very slippery and dangerous. Moreover, even water from the overnigtht dew does not dry up for several hours.
    My wife and my kids have slipped and fallen already and though we really like the look, we want to get rid of the sealant.
    Is there any solution to this problem? If getting rid of sealant is the only solution, any recommendations on how to do it.

  30. Getting rid of the sealant depends on whether it’s a surface or penetrating product. You may be out of luck in that department.
    But I have seen one idea that may or may not work for you; sandblasting the stone (and concrete?). It will cause some of the travertine characteristics to get lost but it will add texture and thus traction.
    If you go the route of sandblasting the walkways, consider then resealing with a product that’s guaranteed to not be slippery when wet — and that will protect your stone from stains.
    I don’t have enough information to help any more than that. But let us know what you do and how you like the results so we can all learn.

  31. I love the Dal Tile slate – “Autumn” #S772 – my neighbor used in her bathroom. She is not happy with the finish the installers used because the tile got so much darker and she lost all the “blues” in the tile. Personally I like the darker color and would like to reproduce it in our house. What finish would I use to do this?

  32. I have a slate floor on outside covered patio. The floor stays dry for the most part, however, the outer two rows of tile get rain water and occasional pool water. Recently the these tiles have started flaking and deteriorating. Not sure what to do? Can I treat or seal? Do I need to replace? If replacing, can I replace affected tile or have will I have to replace the whole patio?

  33. I think you can seal it in place to stop the deterioration. Clean up all the loose slate before starting the sealing process. Use a penetrating sealant and apply according to instructions. If that doesn’t work to your satisfaction replace the affected tiles. Work to match the aged grout as best as possible to minimize the differences caused by the repair.

  34. Hi
    I have installed Indian Autumn slate…
    I have already done a bathroom in it by installling slate grouting and sealing with a water based sealant.The look is nice but i like it more wet look…The question is the new contractor wants to install my new areas front entrance and side where lots of snow and water will come in from feet.He says lay,seal with this oil based sealant and then grout.Doen’t this leave the grout unsealed and i question oil based?
    Thanks Tammy

  35. You are correct that the way your contractor wants to seal the floors the grout is left unprotected. And I share your concern about the oil-based sealer, though maybe for different reasons. I am concerned about the offgassing and air quality in your home.

  36. I just installed a honed slate floor. I’ve grouted it & cleaned the tile. I read to leave floor cure for 30 days before I seal it. How do you keep it clean until then? Also, I got 511 impregnator sealer . Is this good or do you suggest something else?? Thx lynne

  37. It’s a balancing act between exactly following directions, like letting the newly installed floor cure for 30 days before sealing it, and protecting your investment by sealing it before you start using the floor. Few people can let their floors sit unused for 30 days — we need to move into our home or office and get on with life.
    Talk to your installers to see what they recommend. If they are going to warranty their work you should follow their advice.
    I don’t have experience with 511 and can’t recommend anything in specific. Anyone else have a suggestion here?

  38. Hi Floor Lady.
    Do you have any sage words for me about using slate (Chinese- autumn color) as a backsplash and in the area by the stove?
    I adore the natural quality and look of the slate, so I was hoping that a sealant will not change the earthy raw stone look.
    What type of sealant would work to protect the natural beauty plus make them more functional when used near cooking food and water and soap splashes?

  39. I think slate would make a nice back splash for your counters, but I personally wouldn’t use it for behind my stove. Slate would absorb all of the grease and splatters from the stove top and cooking. Yes, you can seal it, but that won’t be a perfect solution and will require more frequent maintenance than other surfaces.
    A porcelain tile stove top back splash would be nice. It would be easy to clean and you could get the a natural stone looking tile. The grout would present much of the same challenges as the slate as far as absorbing grease, but it’s a much smaller space.
    Have you considered using a mirror for your stove back splash? It’s easy to clean, durable, and an added benefit is that it reflects light so the area is even brighter. And if the stove orientation has your back to the room, the mirror lets you feel you are part of what’s going on behind you as you cook.

  40. We rencently purchased a home with slate tile floor. The house was built in the 60’s and the flooring is original. Structurally, it is in great shape. However, it appears that it has been wax’d or sealed over the years. There is a glossy finish to the slate. The grout is very discolored and the floor just needs a facelift. I have had no luck with cleaners so far. I think I need a heavy duty stripper or remove the years of build up. Do you have any suggestions? We were thinking of trying muriatic acid. Thanks for any advice…..

  41. Same question as Lisa on January 2,2008! We rencently purchased a home with slate tile floor. The house was built in the 60’s and the flooring is original. Structurally, it is in great shape. However, it appears that it has been wax’d or sealed over the years. There is a glossy finish to the slate. The grout is very discolored and the floor just needs a facelift. I have had no luck with cleaners so far. I think I need a heavy duty stripper or remove the years of build up. Do you have any suggestions? We were thinking of trying muriatic acid. Thanks for any advice…..

  42. Argh! I knew I forgot to do something yesterday — reply to Lisa. Well, I’ll reply to both of you at the same time. Without knowing if it’s wax or sealant, go for removing wax first. Then you can hit it, to remove sealant, with the big guns if the first approach doesn’t work. I’m not wild about harsh chemical cleaners for your health and air quality concerns.
    To clean the floor of wax use a mixture of 1/4c all-purpose cleaner (make sure it doesn’t have chlorine), 1c ammonia, and 1/2gal cool water. A good all-purpose cleaner to have around is StainSolver — it’s a great oxygen bleach cleaner that’s great for all of your cleaning needs from floors to laundry.
    If that doesn’t work, find a sealant stripper at a reputable flooring store. When the slate is clean and dry, try this trick for fixing the grout mess. Make a slurry of grout — in the color you have now — and with gloved hands wash the grout with the slurry.
    By washing the grout with a grout-slurry you are cleaning it and at the same time filling in gaps. After you have finished the floor let the grout dry and then wash the slate to remove the excess slurry.
    When everything is dry apply a good slate sealer over the slate and grout. Then stay on top of cleaning with sweeping/vacuuming and a vinegar water solution.

  43. We purchased a home that had slate floors throughout the living room, kitchen and dinning room. I don’t know what kind of slate it is. It does seem to be very porous. The floor is beautiful but it is constantly dirty. No matter how much I mop or scrub the floor it is always dirty. Will sealing the slate floor help with this?

  44. Hi, my question is similar to your last. My home has slate floors. When I mop, wipe up a spill or walk on it with white socks, it always leaves a yellow/brown stain, like it is dirty. It will do this just after mopping too. I can’t understand why this discoloration. Does it have something to do with the natural stone properties or is it truly dirty and uncleanable? Also, I have noticed at times it will chip off pieces. Is this normal or does it need attention? Thank you.

  45. You didn’t mention what color slate you have, but I’m guessing it’s light — yellowish tan, maybe? If I’m right about that, and I haven’t had this experience with it, the slate is quite porous and needs to be sealed.
    The chipping tells me it’s probably a soft stone, which goes along with porous, and gets damaged pretty easily. There’s really nothing you can do about that other than take some precautions.
    One precaution you could take would be to put several heavy-duty coats of sealant on the stone. That would possible add some protection from chipping, but it would also detract — in my opinion — from the natural stone qualities.
    Other precautions from chipping would be to have throw rugs and runners in the heaviest-traffic areas. You could also make your home be shoe-free and not drag things across the floor but carry them instead.
    Good luck. If you will, please tell us what you ended up doing so we can all learn what works and what doesn’t.

  46. Hi, we had a new slate floor installed 6 months ago. The contractor sealed the floor and days later, the floor started looking chalk-y and dirty. We scrubbed the floor and re-sealed it with a higher sheen sealant. The slate looked great for a couple of days and then started looking filmy and dirty again. We’ve done some research on the problem and suspect that our contractor did not seal the slate before grouting and then applying the sealant. Any suggestions on how to restore our slate to it’s original beauty? No matter how much we scrub and clean, the floor always looks, dull, dirty and chalk-y once it dries. Thank you!

  47. That’s got to be frustrating! When you resealed the slate after the contractor did the original sealing job, did you strip the original sealant first? What kind of sealer did he use — penetrating or surface? There are a few questions that need to be cleared up before we can figure out what’s going on so you can figure out what to do next.

  48. Hi, I purchased several boxes of slate tile. I spoke with some questions I had. Somehow during conversation they suggested that I NOT space the tiles to give it a ‘continuously’ look. I did lay the tile out in this fashion and it is actually quite more attractive, to me anyway. I’ve tried searching for this or even pictures but haven’t found anything! Will this cause any problems for me?

  49. You know, in the “olden days” that’s how stone floors were put down. If the subfloor is solid the biggest problem I see you will have is that stuff will get into the cracks. Not a terrible problem in my mind.
    If the subfloor isn’t solid the problem I see is that the stones will settle unevenly and one corner will rise causing tripping problems, potential breakage, and a generally uneven surface which is uncomfortable to walk on.
    Let us know what you think when you get them in place. I think it’s a great idea, personally.

  50. We recently puchased a home in Maine with Vermont (I’m an amature rock-hound…I know rocks pretty well) slate floors in several rooms. The house is just over 20 years old. Fortunately, it doesn’t appear the previous owners have done anything to the floors except occasionally wet mop and walk on them…lol. No sealers. Problem is, the grout is fairly degraded in the high traffic areas and there a 3 slates that feel loose. Question is: Should I route out all of the old grout to fix the areas where the grout has failed? What’s the best way to pull up a loose slate without destroying it? Should I clean and seal the old grout where it hasn’t failed or replace it?
    Finally, I put a Moosehead dining set in the dining room…too late, I put felts on the chair feet. There are several seep scratches/scrapes where the metal feet were slid on the slates. How do I get rid of the scrape marks?
    Thanks, Chuck in Maine

  51. Repairing stones and tiles can be challenging and often more work than you think it should be. You can try to route or chisel the grout away before removing it.
    The bigger challenge may be removing the tiles from the mortar it’s in. You can hope that through time the mortar has degraded or crumbled because of the lack of support from the grout that the stone will lift out “easily”. As with lasagna or pie, the first piece is the hardest to get out nicely. If you can get it out the others will follow more easily.
    If you realize you can’t get the stone tiles up without breaking them, consider regrouting using sanded caulk. The silicone in the product will let the tiles move slightly without cracking.
    Once you finish the job, then you can seal it as you want and have a great looking floor that’s durable and easy to maintain.
    Regarding the scratches your dining room floor has, I’m not really sure what to suggest. I don’t know how the tiles were finished by the manufacturer so don’t know if you can recommend sanding the scratches out or if you just get to enjoy the character introduced to the tiles with the scratches. It’s possible that when you seal the floors you will disguise the scratches.
    Good luck!

  52. Hi, my wife and I purchased slate tiles to finish our half bath. The tiles are 2 x 2 in 12 x 12 sheets.
    We did not seal the tiles before putting them down, and we grouted yesterday. We cleaned the tiles, but apparently did not do a good enough job. We were really struggling with the inconsistent height of the tiles. As we cleaned, the grout pooled up in the lower tiles, and also in natural features of the slate. Any recommendation on how to clean up this remaining grout? We tried removing it with a vinegar solution. It was a good start, but didn’t get us close enough to a finished product.
    In addition, once we get the tiles looking good we plan to seal them to provide a wet look. Any advice on what kind of sealer to use, how to apply it, and how many coats we should use?
    Thank you!

  53. Did you wash with the vinegar, or scrub with a green scrubby? I’m sure there are strong chemicals you can use to get rid of the grout in the slate dimples, but I don’t know what they are.
    Your flooring store should have suggestions for what the manufacturer recommends for that slate. Be sure to get one specially formulated for slate.

  54. I love your site, thank you for doing this and answering questions and helping people.
    We are in the process of choosing a slate sealer and I found another site with information on a specific company (Aldon) and I feel they also do an excellent job of educating and have training videos and such.
    Roy described a problem we hope to avoid and we also want the “wet sealed” look. I want to offer this site as a possible help for Roy’s problem of removing grout from his floor…
    They have a product called “Grout Residue Remover”
    At any rate my question is have you heard about this company and their products, and are they recommended?
    If they are not, then please go ahead and edit my post to remove any unhelpful info.

  55. Hi, my family moved into a new home 6 months ago and had the builder install ‘California Gold” slate tile in the front foyer. Some people have mentioned we should seal the floors but we aren’t sure if the builder already did this. One contractor told us that if water beads on the tile than that means it has been sealed, is this true? At this time water is absorbed by the tile (doesn’t bead).
    The tile still looks fantastic but we want to make sure it lasts (at least until we’re finished paying for it). To seal or not to seal??? Any tips on what to use if we should seal it?

  56. Hi All,
    We are installing slate tile (a Lowe’s stock version) in our kitchen. I’ve seen much discussion about the importance of the subfloor prep but it varies from cement backerbd to layers of plywood. I haven’t taken up my existing flooring now (pergo snap together product) to inspect the subfloor but the idea of using cement backerbd is not exciting since it’s soooo heavy and for a layman, can be tough to work with. If I go with plywood, how do I determine the thickness of the plywood subflooring? I’m also concerned about “layers” of plywood that could raise the height of the floor, making the transition into the dining room awkward. Has anyone had this same challenge? I appreciate the feedback. Project to start in about a week. P.S. I’m open to using backerbd but would prefer not to!

  57. Regarding the “California Gold” slate flooring, yes beading water indicates the floor has been sealed. It’s too bad your builder didn’t take care of that before you moved in, but such is life. Find out what the manufacturer of your flooring suggests for sealing the floor to keep it beautiful. Then make sure you let the next homeowner know what you used so they can maintain the floor in the same manner.

  58. You’re right to be concerned about the backerboard weight since your joists might not be strong enough, to carry the load of that and the slate. Unless you have 3/4″ subfloors you need to add a layer of plywood or OSB to help the slate be supported properly. And yes, you’ll have a bit of a height difference between the slate and the carpet.
    If the floor is durable enough as is and you don’t have to add anything to the subfloor, you still may have a height difference because the slate might be thicker than the Pergo. Pay attention to doors, baseboard and appliances too, regarding the height changes.

  59. I was looking for help with slate which you answered ,however, I have a question for the rest of the house…we are retrofitting an old heavy equipment shop to live in. The space is 1000 sq. ft and the flooring will sit on an existing concrete floor …we had the floor sandblasted but there are too many holes and problems to leave it as it. We are looking for one flooring solution for the whole open concept building, kitchen, living and bedroom. I have a dog, the area is sandy, the walls are all white, I dont want carpet, hardwood is too expensive…is laminate wood our best solution?

  60. Laminate is a great flooring, but I’m not sure it’s right for you in this case. Depending on the laminate you have somewhere between a thin and very thin wood veneer as the top layer. I’ve seen laminate hold up with dogs, hiking boots and gravel, and general daily wear-and-tear. But sand and dogs might be too much for that floor; I don’t know your situation well enough.
    Ideas for you to bounce around — in addition to the laminate idea — include ceramic tile, stone, linoleum, and stained concrete.

  61. Hi again. Thanks for answering my Q about the weight of the cement bkrbd. I’ve since discovered that we have 2 sheets of plywood totalling 1″ substrate under our pergo flooring. However, I’ve seen instructions that say you can only lay the slate tile on top of exterior grade plywood….if it’s not exterior grade, is there a way around it; can I prep the plywood to compensate (without having to use bkrbd)? Appreciate the input.

  62. Did the instructions say why exterior grade plywood was required/recommended? Immediately I can’t think what difference it would make. Exterior grade is cheaper than interior grade and the installation will “ruin” the interior grade, but neither of those is reason to require exterior grade.
    I think you can go with what you have.

  63. installing California gold slate tile in 2100 SF office environment. Buying from the depot, not using their installers. $$!!. How much overage do I buy for my independant installer? Concerned about running short due to breakage, and then not having the new stuff match.

  64. It seems to me, based on my various flooring adventures, that you can hardly order too much overage. I’d go with at least 10% overage just to get your through matching colors now and breakage. And to be safe for the future, consider anther 5-10% overage.

  65. We’ve installed polished green gold Indian slate. We haven’t gouted yet. Do you seal polished slate? When grouting, should we mix sealer with gout instead of water? P.S. I like the natural look of the slate. My husband seems to think that maybe he should not have installed the Indian slate, seems like there are alot of bad things said about it. But we are beyond the point of no return. We need help before we start grouting.

  66. Even polished slate gets sealed. Though the burnishing that creates the smooth surface creates a less porous finish than “raw” surfaces have, it’s still porous and will absorb spills. You wouldn’t mind water so much but red wine and oil/grease would be a drag.
    Your idea about mixing sealer with the grout is an interesting one, but one I have no experience with. I don’t know if that would work or not — check directions on both the sealer and the grout. But even if you do that successfully (and I’m thinking the chemistry might be all wrong to do that) you still have to seal the slate so doing the slate and grout in one application would be the way to go.
    I hear lots of negatives about this slate — mostly because it’s so porous that it seems too fragile. But it’s beautiful, so hopefully will be worth any hassles.

  67. I just put down a slate floor. It’s really nice but when I sealed it with two coats I loved the look of it wet. Can you tell me what I can use to keep that wet look after I have sealed the tile now?
    Thank You,

  68. I don’t have experience with sealing slate floors to get the wet-look, but there must be a product that does it because I see such floors. My guess though is that such products are really bad for air quality and therefor for your health, but keep looking to see what you can find.
    Someone here may have the answer too.

  69. what kind of sealer will i use for natural marble or travertine to seal the front of an active fireplace that will be exposed to the heat and coal?

  70. Good question, one I hadn’t thought about or been exposed to before. I’m not sure that flooring gets any hotter than flooring exposed to direct, southern sun. Double check when you buy to make sure that situation won’t be a problem. Try AquaMix’s Enrich’N’Seal.

  71. Hi, Very informative! My question is, when sealing the slate should I seal all sides of the tile? I am using the slate for exterior over concrete. It was suggested to me that sealing all sides might be a good idea prior to installation. I have a worry that the mortar might not stick to the tile as well.
    Thanks , Doug

  72. If you read the entire thread of comments you’ll see there are lots of different opinions on how to best install and seal slate. When you get opinions that contradict each other it’s hard to know what the best way to proceed is. I always fall back on asking the manufacturer for their recommendations. In writing.

  73. in your advice it says to let the grout dry a week or so before cleaning the slate, my question is, do i leave the hazy look on there or do i need to get it off now and then come back in a week with a good washing? a sealer was applied before grouting.

  74. My concern with washing it too early is fear of gouging the grout before it’s cured enough. Chances are I’m being excessively cautious about that and the floors can be cleaned much sooner.
    If there is enough sealer on there for your comfort, don’t worry about sealing it again.

  75. my real concern was whether the grout on the slate will not come off if i leave it for a week. i’m refering to the haze you get when you grout. thanks for your quick response

  76. how do i seal glass mosaic tile used as a back splash on the kitchen counter? After it was installed I cooked something that splattered grease and now the tile has spots on it? Any suggestions?

  77. Hi Sara,
    I think I’d start by contacting the installer and tell them what has happened. I don’t see why it wouldn’t have been sealed after installation if it’s in close enough proximity to your stove for grease to get splattered on it. I also don’t understand why grease would leave permanent spots on the glass either. Have you tried using a water & Dawn dishsoap solution to make sure that all of the grease is off?

  78. Hi – I have had the slate sealed approx 6 years ago and it was done with some kind of acid wash?
    it has worn off and I would like to have a gloss sealer on it now.
    can that be done? and what should I do as I am tryimg to stay in a budget here.

  79. Hi Rose! A mild acid wash is usually done to remove grout haze which has occurred as the flooring was installed. Grout haze is a very fine film where the grout exces “spilled over”, if you will, onto the slate and was cleaned up, but it still leaves a very fine residue. The next step would have been to apply a sealer. You don’t mention if your floor was sealed after this, but I’m assuming it was. If so, it would be a good idea to strip the old sealer as it is probably unevenly worn and apply the new sealer of your choice. If you read around the site, you’ll find suggestions on both stripping & sealing, don’t forget to read other people’s posts and the answers that I supplied. If you need more help, let me know. I’d love to hear about the choices you make and the results – be sure to post back to share your experience with others! :~)

  80. I have slate tiles that I wanted the wet look on…my installers applied a penetrating sealer too heavy and left a white residue on the tiles. they applied the sealer with sponges and let air dry. How can I get the wet look on those tiles if a penetrating sealer was applied? Please advise – Thanks

  81. I am trying to find out the “food chain” for slate. Does it all come from Wales? China? How does it get to US? Do companies that sell it also own the quarries? Thanks!

  82. Hi Jeff! I’m sorry to hear you’re experiencing such a dilemma! You may not need to completely remove the sealant that’s there; you may need to thin it.
    The haze could be caused by several things. It could be the use of a water-based sealant that’s not formulated for slate floors, in which case you probably do need to remove it and start again.
    It could be that too much sealant was applied, the coats after the first are pooled and giving the white haze look. In this case you could use a white buffing pad under a regular rotary machine.
    I would think that making a call to the company that the installers work for would be in order to see if they’ll make things right for you. If they value their reputation at all, they should.
    Don’t hesitate to ask the manufacturer of your slate for input either. After the sealer matter is taken care of, you should be able to apply your wet look finish. Make sure though that the finish is compatible with the sealer (find out what the installers used!).
    Good luck and let me know how it goes!

  83. Slate typically comes from Brazil, Vermont, China and India. Do companies that sell it also own the quarries? Some do, most don’t. Most of it is sold in rough form to the company that makes the tiles. I would imagine that the rough slate gets to the US in various fashions – cargo ships mostly to ports, once in the US, could be anything – tugs, cargo ships, railroad, truck.

  84. Thanks for the information. Can the same procedures( seal or not to seal) be used when installing slate on an outdoor patio?

  85. Just water is fine if your slate isn’t really “dirty”. What you’re wanting to aim for is to make sure there’s not any dust, grit, etc. – that wouldn’t be good for your finished end product.

  86. My slate floor in the kitchen/dining areas are being laid today. How long should we wait before sealing them?
    Our atrium (which extends from the kitchen/dining) already has slate that has been sealed a while ago. I don’t think it was with a water based sealer. We would like to seal all the areas again(including the newly laid floors) but we are unsure if we should remove the old seal. If so, what product do we use to remove the sealer that is already on the floors.

  87. Hello! We have a house full of dark slate tile with a wet look sealer. It’s beautiful, but we find that the furniture, kids, etc. scratch the sealant. Do you have any suggestions for removing or buffing out the scratches? Also, we have a discoloration spot where our puppy left a urine spot that dried before we found it. Now the spot is grey in color and dull. Thanks for any suggestions!

  88. Elizabeth, most tile I’ve had installed has been sealed a day or two later. I live in a dry climate, which I’m sure shortens the time required to wait before sealing, but your installer should know how long to wait in your climate.
    What are you sealing the new floor with? If it’s water-based and the old floor is in good condition, I don’t know that you need to remove the old sealant first.
    But if the old finish is in bad shape — flaking or peeling up — you of course want to remove it before putting a new coat down. Your installer should have answers to these questions.

  89. Melissa, I’m not sure what’s going on with that slate sealant. It almost sounds like it was the wrong product. The slate floor I grew up with never scratched or stained from puppy urine. But I don’t know what the sealant was.
    I don’t know how to buff out the scratches, but it might be worth trying a white buff pad and seeing if it will polish the surface. We can even hope it will remove the urine stain. If that doesn’t work, you may want to strip the old sealant off and apply something formulated for slate floors. Ask around to see who the best floor people are in your area. They may even be able to help you remove the scratches and stains.

  90. Hi,
    I have slate flagstone around my swimming pool and slate tiles on the pool walls to the waterline. Where exposed to water the slate is either chipping, turning to mud or coming off in thin sheets. I have sealed it many times but it just temporarily slows the process. I figure in a few more years I wont have to worry about it because it will have completely disintegrated. Any suggestions would be greatly appreciated. Thank you! John

  91. Hi John,
    Since some slate may really be a sandstone slate, it’s no surprise it’s dissolving. I’m so sorry you’re having to go this — it’s so frustrating! The only thing I can tell you is you can let it dissolve slowly or remove it and go with porcelain tile or pool coatings.

  92. Hi there,
    We live in Northern Michigan. We built this home about 2 years ago. We had slate installed for our drive way, walkways and patio. Our patio and about half of our drive way (pad in front of garage) is heated with smow melt. The areas that are heated are looking great. The portion of the driveway that isn’t heated is crumbling and layers of slate are pealing off. We need to do something or it will be a gravel driveway soon! Our builder suggests that this is normal and will usually stop pealing and crumbling after a few years. Or he says we can seal it but it would all need to be re-sealed every few years. This is a very large area and we really don’t want the cost or hassle of re-sealing every few years. Help! any suggestions?

  93. Hi Bob,
    Pretty much, your builder is correct. You can do nothing and hope that the flaking stops within a few years. If it doesn’t, you will have to apply a sealer. Sometimes each stone is coated with a waterproof barrier (or the bottom & sides are) so that the top can be sealed after installation. I just hope that you’re not having trouble on the underside too. Slate is porous and usually layered, so moisture gets in the stone itself and the natural variations in the weather (warm/cold, wet/dry) cause the flaking & peeling. You know, water gets trapped, if it freezes then the ice expands………..
    In short, I’m afraid your only choices will be to take a wait and see approach (which means more damage), try sealing it and hope that takes care of the problem, or rip it up and start over, making sure it’s done correctly. There are sealers especially formulated for slate, do your homework to find one that is formulated for outdoor use and is TOUGH. Good luck!


  95. I’m not familiar with the product, but I’d let your flooring guy try that – with the understanding that if it doesn’t work & wear well that he will have to come back, remove it again and try something else. You’ll get some ideas from looking through the other posts and articles.

  96. Hi, My tile guy installed my slate (from india) In my bathroom. They cleaned it with a acid cleaner. They only allowed it to dry a few hours and that day put a silicone sealer on it. It looks horrible. It has gray and white hazy spots everywhere. They tryed to strip it again but its still white! Any suggestions?

  97. Hi Monty,
    I’m finding myself stumped on this one, hopefully somebody else will chime in on this.
    My thoughts are (and they’re just my thoughts, so I could be totally wrong!!):
    The silicon has absorbed into the slate, slate is porous, so you may never get it completely removed. Not a good scenario. I do hope I’m wrong and I really, really, hope that the slate was sealed with something else before applying the silicon. You’ve referred to the silicon as the sealer, so…….. gosh I hope not.
    Your tile guy did strip it and reseal it, which leads me to believe that he wants to make this right for you. This is a good sign. If you both come to the conclusion that this silicon sealer shouldn’t have been used and that the slate is ruined, hopefully he’ll continue to want to make right by you and start all over – new slate and all.
    I’m so hoping this isn’t the case!! I’ve read lots of good things about silicon sealers for slate. I can’t help but wonder if there was any moisture behind the slate that could seep it’s way through? It could also be that another brand might work better.

  98. We installed slate tile floors in the kitchen a few mos. ago and sealed them w/both sealer & enhancer and impregnator (to increase sheen). I don’t know how but I’ve noticed what looks like drops of some liquid near the dishwasher/sink area. Can coffee or soda stain the slate after 5 coats of sealer? At first I thought my dogs drool is causing this but they’re not allowed to hang out in the kitchen (due to the scratching). I’m stumped. The next logical question is: can I strip the sealer on only those tiles (3) and reseal? If so, what would I use to do this without damaging the tile? Appreciate any help you and others can offer.

  99. What color are the drops? I wouldn’t thinks that small drops/spills could stain so easlily, especially if they were cleaned up promptly. I’m stumped too. You should be able to strip that small area and re-seal if you need too, but first you’ll need to find out what is recommended to strip what you’ve put on. I wish I could help more, but I don’t know what you’ve used and thus, I can’t tell you what to use to strip it.

  100. Flooring Lady,
    Your explanation regarding sealing seams fairly straightforward. I’m going for a very natural look and am not so worried about staining or scratching. Your comment about better to seal now, than find out it is much too difficult later also makes sense. But, I am getting worried reading some of your “readers comments”. I don’t want to end up with an UNnatural look because a sealer flakes or leaves some haze. Can you recommend any products that have performed well on a constant basis when used by a professional or a very anal DIYselfer?

  101. Hi Angela,
    The big thing to keep in mind is that slate is porous and that slate from different parts of the world have differences in their porousity; thus, the softer the slate, the more porous it will be. I don’t know where your slate is from and so I have no clue of how hard it is, how porous it is. You really need to find that out first. If it’s one of the harder varieties, you may not need to seal it, which would preserve the ‘natural’ look that you’re wanting. If you do seal, make sure it’s a water-based polyurethane sealer. It would also be a good idea to see what the manufacturer recommends.

  102. Hi Flooring Lady,
    We just finished tiling our kitchen with Indian slate. I used a pregrout waterbased sealer to ease in the cleanup. On the instructions it says this sealer will have to be removed before putting any other sealer on, I’m assuming they mean a penetrating one, or it can be used again as a finishing sealer. My question is: Is it best to use a penetrating sealer and then go back over it with a finish sealer? Thanks for your help.

  103. Hi Rebecca,
    It really depends on what you want to do. Some penetrating sealers will darken the slate a little bit, but sealing the slate is awfully important to protect your slate from dirt & spills. After spending your hard earned money on the slate you sure don’t want it to get ruined!
    In short, yes, I’d take of the water-based sealer and use a penetrating sealer, then use whatever you choose on top of that. There’s a range of products out there, so you’ll need to investigate your options to decide how much gloss you want (if any), etc. You might want to find one with a low or no VOC to so that you don’t have to put up with off-gassing (fumes) that could be harmful to breath in. Be sure to use products that are specifically formulated for slate floors.

  104. Hi — we are finally remodeling our kitchen and have fallen in love with a green gold polished Indian slate tile. Reading on-line about Indian slate is now scaring me because some sites even claim that Indian slate is mud! If Kitty is still reading this, I’d appreciate her report on her Indian green gold slate and whether she would do it all again. Our bid is over $5,000 to remove two flooring layers and install and seal it so if we’re making a huge mistake choosing this that we’ll regret in a year or even 10 years, I just will have nightmares over it. I don’t want to have regrets…we’ve waited too long to improve our kitchen to make a huge mistake. We have one small dog and no kids at home any longer, but like most, our kitchen is the most used room in the house and our dog does drip water after drinking from his bowl. Thanks for the advice, Juls

  105. Hi Jules!
    I don’t know that I’d refer to Indian slate as mud, but like you, I’ve heard some horror stories. Keep in mind though, that it can work very well! I would ask your installer questions/concerns about everything you can think of and if you have it installed then be sure to keep notes on what products he uses for grouting, sealers, polishes……..
    Slate can be fragile due to it’s porous nature and slate from different locations have different properties as far as hardness & porousity. You definitly want a finish that will help to stregnthen the slate.
    Don’t forget to make sure to find out if your floor joists are going to be strong enough to support the slate too.
    Reading through the comments associated with this article should give you a real good place to start as far as things to watch out for.
    Make sure that the slate tile you’re considering comes with a good warranty and read the fine print – don’t do anything to avoid the warranty just in case you do have problems. Make sure to do your homework on the installer too and that you have some kind of warranty or guarantee on his installation.

  106. A leaking pot plant has caused a little water damage to the surface of some of our indoor slate flooring – the water appears to have got under the seal and left a visible white staining effect.
    What do you suggest as the best course of action?

  107. How long ago did this happen? If it was just in the last couple days, I’d give it a while (about a week) to see if the white marks fade away – it is possible! If it doesn’t go away, I’d try buffing it with a white pad. If that still doesn’t work, I’d be afraid that you’ll have to strip that spot and re-apply the sealer (if needed) and finish/polish. You could try it, but don’t be suprised if you’re not pleased with the results. If you don’t like the results then the floor will need stripped. Since I’d presume that the plant will be located on the same spot, you might be able to live with the spot fix. Be sure to put some sort of an underpot under the plant to catch excess water – it’s beneficial to the plant too as it can sip water as it needs it if there should be any overflow. ;~)

  108. I’ve sealed my slate on the front and sides with a penetrating sealer. Is it necessary to seal the back also?

  109. Hi Polly,
    It depends on what kind of a floor you’re laying the slate on and if there is already any existing moisture. If there is, then you need to address the moisture problems first and make sure you put down some sort of moisture barrier – whether it be under the new flooring or by applying sealer on the bottom of slate. As expensive as slate is, I’d really recommend doing both if moisture is an issue. It may sound like overkill, but moisture sure can ruin a nice floor!

  110. We have a slate floor on our outside patio and a few of the slates are starting to flake off rather large pieces. Short of replacing the slate what can be done to prevent further damage.

  111. Hi Al,
    Ewww……that’s not good! You’ll probably need to seal the slate really well, most likely with an oil based sealant. Slate is porous, and moisture gets into it from the dew & rain. The temperature changes also cause it to expand and contract, all of this will cause flaking. Don’t be stingy and just use one coat – use at least two, more is better. Caution: this cna make your tile slippery when wet, but there are products to help keep this to a minimum.
    If you go to your local home improvement store and tell them what’s going on and what you want to do, they should be able to guide you to the right product(s). Good luck, and be sure to follow the directions on the label.

  112. Hi,
    I have just installed beautiful tile in my bath.
    The accent is a 1 inch mosaic from India that has some shimmer and I would like to have look like it’s wet all of the time. Can you recommend a product that will achieve that look?
    I’m very proud of the project that my husband and I have so hard on.
    Thanks for your help in advance.
    Pam G.

  113. I’ve heard very good things about Aqua Mix products and I’m sure there’s other good products out there as well.
    Is the mosaic ceramic or glass? I’ve seen both, so I was just curious. What you use to get that high sheen finish is going to depend on what the mosaic is made of. Aqua Mix isn’t recommended for glass tiles.
    You could also contact the manufacturer of your mosaic and ask them what they recommend.

  114. Hi, I am installing slate tile on an outside porch. This will be placed over concrete that has been painted with a latex paint. Is it necessary to remove the paint before laying the tile. Also the concrete has a rough coating over the top of it to prevent slippage. Does this need to be removed as well? Thanks for your help.

  115. It will most likely have to be removed. Sorry, I know that’s probably not what you wanted to hear! There’s a smallish chance that it could just be roughed up to help the thinset/mediumset, whatever you plan on using to adhere, but since there’s no way to tell before hand if that’ll work it’s just best to strip it first.

  116. I just finished installing and grouting 12″x12″ Indian slate tiles on my open, covered front porch. After admiring my work I decided that i should do a search on how to seal it. Lo and Behold….. I discovered that I should have sealed the tiles BEFORE installation! I’ve wet-sponged the tile surface and removed the grout deposits but there is still a slight haze on the surface when it dries. The surface looks great when it is wet. I plan on sponging it at least one more time (It will be the fifth time.) Is there some special cleaner that I should use on it while the the grout haze is fresh? Will the slight haze go away when I seal it? What type of sealer would you recommend? How long should I wait to seal it? Thank You for such a great resource!!!

  117. Hi Bill!
    You should be proud of yourself – that’s one heckuva project you’ve undertaken! All you need is water to sponge the tiles off with – microfiber cloths work even greater wonders! You do need to get the haze off before you seal though – otherwise that haze you see will be a permanant blight – at least until you get fed up with it enough to strip the porch and reseal it. Just be sure to keep your water as clean as possible otherwise it’s going to take quite a bit of work before you get totally rid of that haze. Try wiping each tile with a damp microfiber cloth and finish with a dry one – that might do the trick a bit quicker – can’t hurt to try it anyway.
    I’ve heard great things about the Aqua Mix product line and they do have a high sheen product if that’s what you’re looking for. Some high sheen products can be rather slick to walk on, so that’s something you’ll want to inquire about.

  118. Hello again and thanks for such a speedy reply…Soothing words for a worried mind…I think that I speak for all of us troubled souls who think that they’ve royally screwed things up when I say……You’re allright, lady!

  119. Aww…….thanks. That’s what I try to be here for, but it sure is a nice feeling when somebody takes the time out of their busy life just to drop by and say “thanks”. You made my day Bill!

  120. I just had a slate floor installed on my covered porch. It is lovely. The installer suggests we have it sealed but never said it could be done before laying the floor. After grouting, he hand washed it numerous times but grout still remains on the surface of the slate in the many crevices. I tried scrubbing the grout off with water and a brush but that doesn’t work. If he does the job he would power wash it first. How can I do this myself? Also, can you suggest a sealer for a wet look? Thanks for your advice.

  121. We just had a slate tile floor installed in our new kitchen. According to the installer, it was sealed both before and after the tile was installed. It has a natural finish (no shine at all). We have had several greasy things fall to the floor and leave a mark. Can you please tell me what exactly “mild soap” means? Do you mean a Mr. Clean or Lysol tile floor cleaner or dish soap? Plain water does not seem to remove the greasy stains. Any suggestions?

  122. Hi Leda,
    It sounds to me that there wasn’t enough sealer applied. Be sure to put an extra coat or two on the floor after you take care of your stains.
    StainSolver is a very good product that I can recommend for this situation. It should help so long as the grease hasn’t absorbed deeply into the stone. I would think that dish soap should work too, especially something that cuts grease well, if you don’t want to wait until you can get some StainSolver.

  123. I have a black slate floor that has a penetrating sealer – matt finish. We have had 2 or 3 different acrylic top coats that we have tried and removed over the years because we were unhappy with them. Now the floor is hard to keep clean because the dirt seems to stick to it. I would like to try a wax. Is this going to be a problem? If I had to remove the wax would the remover ruin the sealer? Would wax make it slippery? Is a paste wax a good solution?

  124. Hi Nina,
    What are you cleaning your floor with? Some soap type cleaners (esp. if you mix dish soap with water) actually leaves a sticky residue that attracts dirt. The only thing you should have to do is damp mop with a mild vinegar/water solution (1 c. to 1 gallon water) and ‘polish’ it with a dry mop so it doesn’t look smudged.
    As far as your other questions……. Yes, there are wax polishes that can be used. As far as damaging the sealer when removing the polish, it’s going to depend on what kind of sealer was used, what kind of wax was used, if the stripper is something that will remove both……you get the idea I’m sure. The good thing in your case is that if you do decide to strip the polish, only leave the stripper on long enough to do the job, don’t leave it on so long that it has the opportunity to strip the sealer. Remember too, that slate is porous, which is why it needs sealed in the first place, so that spills & dirt don’t have a chance to work their way into the stone. It’s going to take a bit of time for a stripper to actually get into the stone. How much time? I’t going to depend on how much wax was applied, how much sealer was applied….
    As far as what type of wax to use……. make sure the wax is specifically formulated for slate flooring. AquaMix has a good variety of products for slate flooring and seems to have a good following with lots of happy customers.
    I hope I’ve helped, please drop back by if you have any more questions.

  125. Help! About 6 months ago, we remodeled a bathroom and had Indian slate tiles installed on the shower floor and walls. The contractor sealed it and told us to wait 48 hours before using it, which we did. We immediately noticed a white film over almost the entire floor, and what appears to be rust stains in some areas. I am very unhappy with the way our expensive, brand new floors look and hope you have some advice? Thank you!

  126. Hi, I emailed a couple of weeks ago. As you asked what kind of cleaner am I using and sealer. We had originally sealed with Stonetec and had used an Aldon acrylic finish on it that after a few weeks started to look smeared and just bad. Black slate is harder to keep up than other colors, – I think I made a bad choice. The floor is about 15 years old. We totally removed all finishes and sealers and resealed with AquaMix Color Enhancing Sealer which for a couple of weeks was wonderful. Any dirt or dust was easily removed with a dry dust mop.I wish there was some kind of finish that could be put on the floor every few weeks that would keep it like that.But, as soon as the little bit of oil that had remained on the surface finally dried in or was washed off totally we started to have problems. I like the natural dull finish though and was told to use a neutral cleaner so I bought ZEP, but then realized that it has to be rinsed very well after washing. What a pain. Anyway now any dirt or dust – a foot print- seems to stay until washed off and no – there is no sticky residue on the floor. I have been damp moping (daily) with just water. I wouldn’t think vinegar was neutral.

  127. Hi Nina,
    A weak vinegar & water solution helps to clean the floor of course and the vinegar helps to prevent streaking – just like if you’d use it on windows.
    Have you called AquaMix and talk this over with them? I’d be very interested to hear what they have to say, tips to keep it easy to clean. Perhaps it needs buffed/polished a bit? How many coats did you apply?

  128. Hi Mignon,
    It sounds like you need to call your installer and tell them about your situation. Something is definitely not right, though I couldn’t say if it’s grout haze, the sealer wasn’t fully cured or what based on what little information you’ve provided. I haven’t a clue about the rust stains either – that’s really odd to hear of. Perhaps it’s just a natural discoloration in the stone? I wouldn’t think that rust stains would develop in only a couple of days. Your installer really needs to see this and should offer to make this right.

  129. Hello,
    I’ve had Indian slate tiles laid in my kitchen today. They are unsealed, and have a white film over them. My installer said I needed to wait 24 hours to allow everything to settle and that there is a solution you can put on the tiles to get rid of the film and bring out the colour. I’m concerned as I’ve just read similar problems from other posts. Should the tiles have been sealed first and can this really be put right?

  130. Hi Nyeniba,
    I’m sorry I didn’t see your post sooner. I guess you’ll have to wait and see now. I hope he’s correct and that it turns out ok – if it doesn’t then ask the installer to make it right. I’m hoping that the slate was pre-sealed before he grouted and that maybe you didn’t know.
    Hope everything turns out ok.

  131. I am installing a soft slate. I am going to pre-seal it before I lay it so I can get the exact color it will be after sealing. This will help me with my layout scheme. Should I use a penitrating sealer for pre-sealing? If so, can I cover that with a surface waterbase sealer after I have grouted? Thanks

  132. Hi Marty,
    Where is this new floor material going to be located? Inside, outside…..? What room? To make entirely sure that the products you use will be compatible you should really check with the manufacturers (or where you buy your products) once you think you know what you want to use, but yes, with soft slate you usually put a couple coats of sealer on, then grout, then clean your tiles really well to remove any excess grout, and then seal again so that the grout & slate are sealed.

  133. I had a rough slate floor installed on my outside patio. (Blue, green & Rust colors) The contractor that installed the floor said they would be back in two weeks to seal the floor but they never came back or returned my calls. My husband put a slate sealer on the floor but it didn’t seem to work because the natural rust in the tile keeps bleeding in the grout and over the sides of the patio staining the paint trim. Can you recommend a good outside sealer to prevent this from happening further?

  134. AquaMix has a good variety of products, though I’m not sure what you’re going to really need to do. If he already put a slate sealer on it, then it should be sealed. Not knowing what product your husband used, I would suggest that you call the manufacturer of the sealer – there should be a phone number on the container.
    Sorry to hear that the contractor didn’t keep up their end of the deal. I hope you finally get a hold of them – they should refund you a portion of the job cost since they never came back and sealed the slate.

  135. Hi- We had someone install a slate tile floor and it wasn’t sealed before the grout was applied. The slate is from India. Is this ok and what should we use on it now to clean the haze off and then to seal it? I’m a little worried after reading the other posts. Thanks so much!

  136. I have a nightmare of a situation with my black slate tile floor. The original owner sealed the tile with polyurathan years ago which looked nice when I bought the house. I have had a tenant in the house for 9 years who was a very poor housekeeper. After he left I had a floor cleaner come and he used chemicals and cleaning products and left the floor in a real mess. The polyurethan is half peeled off and it looks something like badly chipped finger nail polish. The floor cleaning company refuses to come back stating they wouldn,t have taken the job if they had known they were dealing with polyurethan. I want to sell the house but no potential buyer would consider buying with the floors like they are.
    Can you tell what kind of chemical could be used to strip this floor? On the plus side, the areas of the floor which where stripped clean during this process look nice so if I could just finish stripping the floor everything would be fine.
    Please help?

  137. Hi Karen,
    Use the link above for AquaMix – they should have a product that helps. Better yet, give them a call (800) 272-8786 or (800) 366-6877 to make absolutely sure which one of their products would do the best job. They also have products to seal the slate, regular cleaners and deep cleaners.
    I’m suprised the people who cleaned the floor didn’t do a ‘test spot’ first before cleaning the whole thing. Too late for that now though……..

  138. Hi,
    I installed slate on the floor and wall around my wood stove. I applied it over cement board on the wall. After a winter of heating, in the spring, I had a few tiles pop off the wall behind the stove. Not much mortar had adhered to the back of the tile; it was very slick. Tough job chipping it off the cement board, though. Before reinstalling, I gouged the back of the tile with a wet saw. Wish I’d read your recommendation for mixing grout with a penetrating sealer instead of water.
    Only about 5 of a couple hundred tiles fell off and I hope my problem is over. Will grout help at all in keeping them on (Winter came before I had time to grout)?

  139. Hi Allison,
    You need a finish and/or sealer that has what is referred to as a “high sheen”. AquaMix makes such products, other manufacturers manufacturers make these types of products as well. Use a sealer if it hasn’t been sealed already.
    You didn’t mention what room the tiles are in – you will want to be careful of slipping when having a high sheen floor – there are products to help with this as well.

  140. I need a recommendation for someone to work on my slate foyer. A product spilled and melted the sealer in an area on the floor. The floor has a shiny surface,
    I live in the Oakland County area in Michigan.
    Any recommendations would be appreciated.

  141. Hello,
    I have a slate floor in my sunroom that gets infected with mold/mildew during the humid Summer months. Is there any sealant or other coating I can use to help prevent this?
    thanks, Gerry

  142. I had a daltile slate floor put down outside in my lanai in Florida. Two areas are covered by roof and the rest by screen – there is a pool in the middle. The tile was sealed – it looked beautiful for 2 days – then the trouble started. Some of the stones are releasing something that turns to rust. So there are orange/rusty stains on large areas of the slate and grout. Installer came back and bleached areas, replaced others and resealed – problem still there. Now installer is bringing back chemist to look at problem. Any ideas on a fix?

  143. Hi Bernadette,
    It sounds like moisture from under the slate working it’s way to the top, bringing the stone’s impurities along the way. Did the installer put down a moisture barrier before doing all this stone work? Sometimes the slate is sealed all over before putting it down, but it doesn’t sound like that was done either. Moisture could still get through the grout perhaps, but neither would be happening if the whole thing had a vapor barrier under it.

  144. Hi Flooring Lady,
    I have slate floor throughout my kitchen/eating area. The builder (who lived her) applied a shiny finish that has peeled off in places. I’m working on removing it entirely. However, the bare tiles show grease spots (I think where food has dropped — four kids in the house). Can I remove this? Can I keep the non-shiny look of the tiles but still seal them against kitchen stains?
    Thank you!

  145. Hi Kate,
    AquaMix has a whole range of products for slate floors that will take care of everything that you need. Wish I had a nickel for every time I’ve mentioned they’re products. ;~)Heh, maybe I should contact them and tell them about this site! LOL! Seriously, they’re great products and I’ve never heard of any complaints. They have products to strip & deep clean the slate as well as sealers for creating a glossy finish or natural look.

  146. I have just had slate tile installed in my bathroom on the floor. The tile was not sealed prior to putting down or grouting it. I have washed it 4 times with water and still have somewhat of a haze on it. Do I need to wipe it down more? I would like to seal it as soon as possible so I can get my bathroom put back in order. Thanks

  147. Hi Kelly,
    Yes, you need to get the grout haze off, or else it’s still going to be there when you seal and it’s going to make the slate look horrible. There are products that do a better job of removing the haze, such as AquaMix Grout Haze Clean Up. I’m sure there’s other products to be had if AquaMix products aren’t available locally. Time is of the essence, the sooner you can get the grout haze removed, the better.

  148. thank you for the reply, I talked with Lowes and they said to steel wool the tile vaccum then seal with slate/stone sealer is this correct?

  149. Hi Kelly,
    This is correct so long as the grout hasn’t penetrated into the slate – remember, slate is porous! – and if you try it, use very fine steel wool – #000.
    I also fixed my reply to you yesterday – the link to the product I was referring to wasn’t showing up. Grrrr…… They have a whole line of products formulated specifically for slate, so you don’t have to worry if it’s the ‘right’ product.

  150. Hi Flooring Lady;
    I’m begining a 1300SF new install in a house I’m building; using Chinese “Ming Valley” multi-color slate. The slab has a few cracks that were opened and filled with epoxy filler – would you reccommend a membrane, and would you use it just over the existing cracks, or the whole area that’s being tiled?
    Suggest a brand?
    Pre-seal before setting and grouting?

  151. Hi Mark,
    Definitely seal before setting – all over. Works as a vapor barrier that way, as well as making grout so much easier to remove from the tile (nobody is perfect!).
    I’m not familiar with what you’re referring to as a ‘membrane’, most people just seal and then apply a finish, if desired.
    As far as products to recommend for slate, I’d recommend AquaMix products.

  152. Hi Flooring Lady –
    I purchased slate and it has a substance that looks like rust. I read you comment above about moisture coming up from under the slate, but this is coming out of the box with the “rust”. I am assuming that the shipment may have gotten wet and that is what is causing the problem. What can I do to correct the problem or should I return?

  153. Hi
    I have a black slate floor in the kitchen area – it appears as if it has been sealed (? matte) in the past although it has all but come off. I have noticed that it is looking very marked and has white marks in areas. What should I use to really clean the tiles, and do I need to reseal it or will good cleaning products be enough?
    Thank you

  154. Hi Louise,
    Probably the best thing to do is strip it then reseal, then apply a protective finish (natural, matte, high or semi-gloss). AquaMix is a very good line of products and makes products for every step. You can check on their website to see if there’s a retailer near you.
    Just in case you or anybody else is wondering, I mention this manufacturer because they have an excellent line of products. Nope, I don’t get a kickback from them for referrals if somebody buys online. I just really think that their products are that good. :~)

  155. Good Morning. We installed a natural slate in a new bathroom, not knowing we should seal first, we had a very big clean-up job of grout after. We fixed that problem with help from your site. Now, new problem. We have sealed the floor 3 times, over an hour between each coat. This morning I went in there and there are streaks of bubbles with ridges across the floor. Any suggestions.

  156. Hi Deborah,
    I don’t see anything on their website page for slate products that has that name. Is it here?
    I do know that you’re not supposed to use sponges with larger pores as bubbling will occur. I know you wrote that you used a large sponge, I don’t know if it had large pores.
    I know the sealing kit that they sell has a sponge with very tiny pores.
    Hopefully you won’t have to remove what you’ve already done. Sometimes you can get by with sanding where you see the bubbles and re-applying the finish (with a sponge that has small pores), feathering out the edges as you go. You might want to give them a call to see what they suggest. Technical services: 877-278-2311
    6am – 5pm M-F, 7am-12pm Saturday PST

  157. We had black slate tile installed in our new cabin in the bathrooms, entrance, mud room and hearth. The installer did not seal the tile and now we are seeing water stains, etc. We would like to seal it now…what should we do to clean and prepare the surface? Is there any way to get rid of the dark water stains?

  158. Hi Greg,
    Obviously, I can’t tell you for certain if any one product will get out the stains. I would recommend AquaMix products. They have a very good line of products and will have everything you need (deep cleaner, sealers, etc.). You can check to see if there’s any place near you that carries it or you can order online.

  159. I installed a slate tile floor in our mudroom. We loved the look when it was first installed….Then i sealed it with a product from Lowes. Not sure of the brand but will check..anyway. the sealer was reccomended for slate,matte finish with color enhancer.It now is very my wife put went from “Summer Cottage” to “Medevil Dungeon”! Anything we can do to bring back the powdery light natural look? I have not grouted yet..not sure on the color. Any help would be appreciated!

  160. We installed slate tiles-they smell funny. When I washed the tiles they really smelled awful. After they dried the smell is not as strong – but they still stink. I’ve sealed them, but not grouted yet and they still stink. Is there anything I can do to get rid of the stink?

  161. Hi Gerry,
    I don’t know if anything can be done, especially since I don’t know which product you used. Take a look at the package, there should be a toll-free number to call the manufacturer. They’ll know for sure if your Medieval look can be removed.

  162. hi, we recently installed our kitchen filoor with slate tiles, and have grouted them . now how long do we wait till we apply sealant?it has been two days since the grout app. thankyou, kiki

  163. Hi Kiki,
    First question is: did you get all of the excess grout removed? Have the tiles been cleaned to where you have also removed any grout haze? You really, really need to make sure or else your slate will look like it has a white film in spots – even after you seal and then the only way to get rid of it is to strip the sealer!
    What are the grout manufacturer’s recommendations for drying time before sealing? Do you still have the package or at least know what product was used?

  164. I slated the floor in my kitchen and lounge and hallway phew! no grouting all butted up tile to tile, but the adhesive and more importantly it’s dust gets in the grain of the tile (i did not opt to seal figuring that it pisses down with rain on the slate in it’s natural habitat so hey!) anyway i recommend hands and knees, hot soapy water with a wee dribble of white spirits and you guessed it plenty of elbow grease, member remember, slate is a wonderfully green product not manufactured but quarried!!

  165. Thanks for your input C4president, not everybody is willing to put such effort into cleaning their slate! A sealer is still a good idea, even if it is outdoors – that way moisture can’t get trapped (or ice!!) and get in between the layers of slate, making your slate layer off (peel off, etc.).

  166. Hi- I’m the one who posted the question about the smell. And yes the slate smelled prior to sealing. I washed the slate prior to sealing (just with water and white towel) The smell was evident before I washed – but when the tile was wet it really stunk. I let the tile dry 48 hours before sealing. After sealing the smell is not as strong, but still there. It’s smelly enough to bother me. My 5 year old says it smells like poop. I don’t think it smells like poop(that’s a five year old reference to bad smells I guess) – but it is unpleasant. Have you ever heard of this before – I googled it and found nothing, but I can’t believe it is unique to me??
    Any suggestions?

  167. Me again. After responding to your comment I decided maybe I’d been living with the stink too long and I was wrong about when it started to stink. So I smelled some left over tiles – no smell. I washed them with water – just a wet kind of musty odor – smelled like wet dirt. When the tile dried no smell. I smelled the bottle of sealer – it has a chemical smell, but not the stink that I’m experiencing. So it must be the reaction between the tile and the sealer. The sealer I used was Enhance & Seal for Slate from Superior Adhesives & Chemicals.
    Is there anything I can do at this point to unstink my tile floor? Let me know.

  168. Hi Jessica,
    This certainly is a stumper. Perhaps cleaning it with a mild vinegar/water solution (1:15 or 1:20) might help with the smell, vinegar is wonderful for helping to naturally remove odors. Please make sure the slate is still well sealed though by checking to see if water will still bead up on it.

  169. My back went out and i was unable to grout for many months. Now the slate is dirty. Whats the best process to clean to close as original as i can get the slate???? thanks, k

  170. Hi Keith,
    First off, define “dirty”. What kind of dirt? What room is this installed in?
    AquaMix has great products for cleaning the slate, just be sure to read over the uses of each product to choose what kind of cleaner you need. Good luck and glad you’re back has gotten better!

  171. I’m a little confused about the sealant steps.
    Should I apply sealant to the tiles _before_ I lay them? Then apply more sealant after the tile’s been layed and grouted?
    When I want to apply a finishing sealant that creates the ‘wet’ look, do I do that before I lay the tiles, or after I lay them? Also, if after, is it before or after I put down the grout?

  172. i am new at this…and put slate in my shower and on the floor in the bathroom. now i am discovering my error, because i cant find a waterproof sealant for the shower walls…….any ideas? help please!

  173. Hi Steve,
    Yes, apply sealant before laying the stone. Why? Because it prevents moisture from underneath the stone from coming into contact with the stone and also makes it sooooo much easier to remove grout that accidently gets on the stone (and it will!). It acts as a barrier. Slate is porous, so grout can actually get into the pores and if it does, it’s a pain in the butt to remove. Sealing first saves a lot of extra work after grouting. After you grout, you have to clean off the excess, and you have to clean it well (and more than once!) so you don’t wind up with grout “haze”. Make sure the slate is dry too before final sealing. To see a line of great products, visit AquaMix – you’ll get a better idea of what products are available, what to use and why. You’d probably be most interested in AQUA MIX HIGH GLOSS SEALER – you can also use it for sealing before grouting as well as after.

  174. Ok. So do you need to clean the slate before sealing it? And if I want a wet look but not nessisarily glossy what type of sealer should I use. Thanks

  175. Hi Laura,
    Yes, yes, yes! You need to clean it super-well – get all the grout haze off of it – I hope you sealed the slate before you layed down the stone.
    You can use a penetrating sealer (it will probably make your stone look a little darker), and follow up with a topical sealer/polish. Since you don’t want high-sheen (glossy), go for a low-sheen product or something that’s a semi-gloss. A good line of products can be found at AquaMix. Even if you don’t use this line, just be sure that what you use is specially formulated for slate flooring.

  176. Hi. We have slate floors in our kitchen. At first i loved them but over the last year or two they seam to have lost any luster they once had. They have only been installed for approximately 3-4 years. I cannot remember what they were sealed with the first time but i know that they were. Can i reseal them? If so, does it matter what was on them before? I want them to have a higher gloss then they ever had before, any suggestions. Thanks,

  177. Hi Torey,
    Sounds like they need resealed. Yes, it does matter what they had on them before and since you don’t know for sure, you’ll most likely have to strip the old sealer. A great line of products formulated for slate can be found from AquaMix – even something more high-sheen so your floor is shinier than it orginally was. ;~)

  178. ive recently laid slate tiles on my internal staircase and sealed them with an absorbant water based non gloss finish. the finish i thought was fine but have been talked into a ‘wet look’ finish for the tiles is there a product that will give me the desired finish without making the tiles slippery/dangerous when wet? the tile ive used is dense with a uniform black/blue colour?

  179. Hi David,
    I would advise to leave them as they are. High-sheen finishes are more slippery and if you add water into the equation then somebody is going to wind up taking a spill eventually. If you think they look fine, then why bother? There are products that are formulated to give a glossier look and have something in them to help them not be as slippery. Check your larger home building/improvement supply stores. A word of caution though – the next finish you use has to be compatible with the first product – if it’s not you’re going to have to strip the first product or you’ll have a real mess.

  180. Hi Kim,
    What do you mean by pale – do you mean that they have a white haze? Has the slate been sealed before? There’s a couple scenarios that could be possible, but I can’t judge because I don’t have enough information.

  181. The slate looks unpolished,dull.I sealed it myself,yesterday I used my shark and it did get up the excess sealer. Now,after reading the blogs,I guess I am lucky.I want to put on a polish—–that is what I am understanding and it has to be compatible with my sealer.Is this correct?

  182. Hi Kim,
    I’m guess you used a natural look sealer, there are ‘high-sheen’ sealers, but never fear, this can still be remedied.
    Yes, you were lucky and even luckier since you know what was used to seal it since you did it yourself! All you need to do is find a compatible product that is high-sheen, or a satin finish if that’s what you prefer. You can either use an actual finish or a high or medium-sheen sealer on top of the flat sealer.
    Good luck, I’m sure you’ll do fine! ;~)
    I’ll be back on in a few hours and will check to see if you have any more questions.

  183. We just had our black, brazillian slate floors installed and sealed by a professional. He didn’t do a good job cleaning the grout off the tile and with black slate…it SHOWS! He isn’t returning our calls to remove it so I want to know what I would need to do to remove the grout on already sealed tile?

  184. Hello Flooring Lady,
    I want to start by saying i have injoyed reading stuff on your site
    Im going to instal a muli colored slate floor in my bathroom. I have small children so bath time can get very wet all over the bathroom. I want the floor to have a wet look to bring out the colors in the floor. what is going the best sealer and when is the best time to seal it? can i seal both befor and after installing or is one going to be better than the other?
    the floor is going to be installed on a contreat slab that had linoeum on it. at some point durnig the slabs life in most on my house there was a black tar like adheaseav used that is extramly hard to remove. we have used a couple of different methods to remove it in other roomes, so we could instal ciramic tile, both seem to have worked. we have not had any problems with the tile coming up or anything like that. In one rome we basicly took a hand sander and sanded the suff off the slab it was very messy and time consuming the next room we used an adheasiv remover that took off a lot of the old adheaseav but not all of it. is there anything specil we should do to the sub floor befor installing slate?
    I would also like to know what is the best thin set to use and what is the best kind of grout to use. or is it ok to use the same kind of thin set and grout i used with the caramic tile?

  185. Hi Crissie –
    I would suggest that you get in contact with this “professional” and demand that he make this right. If nothing else, you’re going to need to know what was used on the floor to seal it so that you could choose the right product to remove it. If this “professional” cares anything at all about his reputation, he will make this right for you. Word of mouth can be a double edged sword.
    If you’re really determined to do this yourself, take a look at the products for slate by AquaMix. You might want to call them too, I know they also have products carried under a different brand name, but I don’t recall what that name is at the moment.

  186. Hi Trudy,
    I’m going to try to tackle all of your questions in order…… ;~)
    I would suggest that you look over the product descriptions & uses at AquaMix”, that way you can explore the options of what you can use.
    Always seal before laying the tile – it makes excess grout and haze much easier to remove, saving time and a big headache! You seal it again after you’ve removed the excess grout & haze.
    Providing that your subfloor in the bathroom is also concrete, hopefully you won’t have to do anything special to it. It’s usually considered a good idea to brush or roll on some concrete sealer or use as a vapor barrier (you can read more about vapor barriers for basements at this article).
    A good method for removing the black tar-like adhesive is simply using hot water – it softens it, you scrape it off. Sometimes you’ll need to use more hot water and a scrubbing pad to remove what you’ve scraped off more thoroughly.
    If your subfloor isn’t concrete, but wood or plywood, you should probably use some thin cement board (commonly referred to as hardbacker) to set the tile on.
    As far as the ‘best’ thin set & grout and whether you can use the same……. I don’t know, because I don’t know what you plan to use. What did you do before? It sounds like you had good results with what you’ve already used in the past.

  187. I have slate floors and slate walls in the shower stall of a newly renovated bathroom. The shower floor is limestone. They are Brazilian and were not sealed before installing. Is is too late to seal them?

  188. hello again the type of grout and thin set i used on the rest of my house is as follo: (this may be more info than you need but then you will know exsctly what i used.)
    CustomBlend Standard Thin-Set Mortar is an unmodified thin-set mortar that offers economy with good bond strengths for basic tile projects and is recommended for floor installations. Good for setting Saltillo and other similar clay pavers.
    Polyblend Sanded Grout’s unique formula offers color consistency, fast setting time and a smooth texture for easy spreading and cleanup. Unmatched for its rock-hard curing properties, it produces dense joints that are highly resistant to shrinking, cracking, powdering and wear. Available in 48 colors. Polyblend is polymer-modified for strength – mix with water for any tile or stone installation. Protected by MoldGard Technology. Exceeds ANSI A118.6 specifications.
    So will both of thers products work with slate tile?
    thanks for the help

  189. Thank you so much! He has finally gotten back to us and was very vague but said he would come “check it out.” Let’s just say he WILL be fixing it. He did at least leave us the sealer so worst case we can do it ourselves. Thanks! This was a helpful blog!

  190. Hi Trudy,
    Sounds like this would work just fine, in my opinion. I always suggest calling the manufacturer to make 100% sure, but I’ll bet you get the same answer. Don’t forget to seal the slate before you put it down.

  191. I just had a natural stone backsplash installed.
    The grout and tiles looks much more “pink” than in the store and my granite is black and gold.
    How can I make the backsplash more “gold” in tone/ color?
    Also,it has not been sealed and I have no clue how to do this.

  192. Hi Debbie, you might be able to stain it before you seal it. I don’t know if you’re wanting a more golden color or more metallic gold?
    I highly recommend AquaMix products for sealing – click on the link! Oh, be sure that you have removed all grout residue before you seal or you’ll have a nasty filmy grout haze on your tiles.

  193. Debbie and The Flooring Lady, I just found this site and have been reading with interest the various topics. Now it’s time for me to contribute a pearl I have experienced in flooring — BioShield wax finish. We have adobe and stone floors in our B&B and use this wonderful product to seal both materials. The finish is lovely, the maintenance is easy and cleaning it is as easy as a damp mop with water. I can’t urge you strongly enough to try it on your slate.
    Since The Flooring Lady seems to be interested in environmental issues I think trying BioShield over AquaMix will give you better results and healthier air quality.

  194. Hi Crissie –
    A big huge NO!. Seriously, do a search at a search site – these products cause nothing but problems. They might look great at first (some don’t!), but it doesn’t last and removal is a nightmare.
    I recommend a weak vinegar/water solution for cleaning (1 part vinegar/15 or 20 parts water). Get yourself a microfiber mop and a spare mop head. Usually just damp mopping works, followed with the dry mop to buff it a little, get up the little bit of residue that may have been left behind. You’ll probably be able to get away with just damp mopping with water too and use the vinegar/water solution for heavier cleaning when needed.
    Did you see the post above yours? Looks like great stuff, but I haven’t checked it out yet.

  195. Regarding your comment above: “Oh, be sure that you have removed all grout residue before you seal or you’ll have a nasty filmy grout haze on your tiles.”
    Is there a way to remove the “nasty filmy grout haze” after it’s been sealed?
    Thanks so much!

  196. Hi Amy,
    BioShield has good products. If you were to call them (phone number at website) they could tell you I’m sure. I keep forgetting to call. Heh…..if you do call, post the branded name here ok?
    You can also go to your local big box store (Home Depot, Lowe’s, etc.) and ask them for a recommendation from the products they carry.

  197. I moved into a condo with a multi colored slate floor (possibly Brazilian from the look). It has been laid over the concrete on our lanai which is also is part of the roof for one of our lower rooms. We had a very heavy rain the other day and got a water leak in the ceiling of that room. I wanted to seal the tile on the lanai to protect the roof from future rains. What is the best product for sealing a slate floor located outside? When I roll the sealant on the slate, will it also reseal the grout or is that a different product?

  198. BioShieldhas a very good line of products for stone, like slate. Has the slate ever been sealed before? You may need to strip off the old sealer if you’re unsure of what type of sealer was on it – they would have to be compatible (old & new sealer) if you don’t want to have to go through the job of stripping. The grout will also be sealed when you apply your new sealer. Good luck!

  199. I have a slate floor that has been previously sealed with Aqua Mix UltraSeal Premium Stone & Tile Penetrating Sealer and I was thinking about applying the Aqua Mix Enrich’N’Seal to bring out the colors and get a wet look. Since the previous sealer and Enrich’N’Seal are both penetrating sealers, do I need to remove the old sealer or can the Enrich’N’Seal be applied over the old penetrating sealer? Would this allow the full effect in enriching the colors and providing a wet look?

  200. We’re installing a “fieldstone” look slate tile surrond on our vent-free, zero clearance fireplace insert. Is it OK to use the same oil-based polyurethane that we used to seal some wood trim to seal the tile?

  201. Hi Craig,
    I don’t know if that would work or not. I’m betting that you’d have to strip first. I’d call AquaMix and ask them. Click on the link and their phone numbers are on the right. They’re wonderful about answering questions.
    If you don’t mind, please post what they told you so that everybody who visits this thread will be able to see it.
    Good luck!

  202. My slate floors were installed without sealing the slate. Is it too late to seal them? They look great – do I need to seal them at all?

  203. Hi Barb, Yes, they should still be sealed to prevent dirt, stains, etc. from getting into the pores of the slate (slate is very porous!). BioShield offers some good *environmentally friendly* options for finishing your slate. Most important thing is to make sure it’s totally clean – no grout residue should remain or else you’ll wind up with a floor that will look horrible.

  204. Hi Joe,
    I don’t know what would be considered “too dark” for you. Maybe if you call the manufacturer they might send you a small sample that you can try on a leftover piece. Hoping you have some left-overs!

  205. I recently sealed my slate for around my fireplace with Thompson’s Water Seal (non-color enhancing) and although it didnt’ turn out glossy it did make it much darker. I followed the directions to a tee. I wanted it to still look almost the same (natural) just sealed. It is ok for the fireplace but when we start our patio I don’t want it dark. Should I try this AquaMix stuff I am reading about or will that have the same results?

  206. Hi Kaela,
    I depends on which product you’re talking about. The Enrich n’ Seal is going to darken it more than their other sealers I would think. Unfortunately, no matter what kind of sealer you use, it’s going to darken the slate some.

  207. We have a slate floor that was sealed with a stone sealer the contractor used. Now our slate floor has a white residue on the tile and the grout (The grout is Black). What can i use to remove this white residue and what should i use to reseal it?

  208. My slate floor is 3 years old…about 700 sq ft. I did seal it originally. Is it time now to reseal? What are the steps necessary.. a deep clean? scrubbing? remove old seal? what products would you recommend for the project?
    there are no obvious stains or worn marks.
    A carpet/floor cleaner company said he would clean it and reseal it for $500!! Too much for me, I can do this myself I am sure.
    Thank you!

  209. Hi Christina,
    YOU shouldn’t use anything – you should contact the contractor and have him do it – let him know you are unhappy and why. He should be more than happy to make this “right” for you if he cares anything at all about his reputation.
    Only other thing I can tell you is to look for the link here at the site for AquaMix – they’ll have products you can purchase (locally) to strip and re-do if you really have your mind set on that.

  210. Hi Karen,
    If the floor still looks good and repels water well (beads up when sprinkled on it – esp. the high-traffic areas), then it doesn’t need resealed yet. You should be able to just clean it well using a vinegar/water mixture (1 part vinegar to 15 parts or more water). If you remember what kind of sealer you used on it, you should be able to just use another coat or two without stripping.

  211. Hi Karen. Our house was built in the late ’60s. We moved in 6 years ago. The entry way has a slate floor that is dull and dingy with paint splatters. I would like to reseal it so it looks shiny again. What do I need to consider in prepping the floor before sealing? Thanks for your help!

  212. hELLO,

  213. Hi Amy,
    You’ll need to clean it good first and then decide which kind of product you want to use on it to seal it. AquaMix carries a good line of products – if you go to their site you can read up on what each slate product is used for.

  214. Hi Eric –
    Click on the link for AquaMix – I think you’ll find that their Enrich ‘N’ Seal is the type of product you want. Other manufacturers have similar products too – I just use AquaMix as an example because I’m most familiar with their products.

  215. After reading about slate tile on your web site I should have done my homework first I just install soft slate and did not seal it first. Your right it is a pain in the butt to get the mortar off, do you any helpful suggestions. I will SEAL it before I grout it should I use a water base or oil base? Your web site had alot of helpful infromation I just wish I would have found it before I started. ALWAYS DO YOUR HOMEWORK FIRST

  216. When in doubt, seal them with a penetrating, water-based sealant. There are products made for removing grout and morter. Check out and choose slate from the flooring finder, surface finder, whatever it’s called. They have products that will do the trick. Doesn’t mean you have to use their products, you can find other products that are similar. This is helpful though to give you a good idea of what you need. Oh, and yep – wish everybody did their homework first!

  217. I have soft indian slate tile I sealed it with sealers choice gold but I don’t like the effect can I use enrich n seal over it or is it to late?

  218. Why can’t you use an oil based polyurethane to seal slate tiles? I have some in my kitchen as a backsplash and it seems that oil based poly would probably make more sense. Would it not be more grease and stain resistant and easier to clean, particularly around where the stove is?
    Please reply,

  219. Hi Edward,
    To find out for 110% sure, I’d call AquaMix at their toll-free number. I think AquaMix makes the product you used. Copied from their website: Give us a call at 800-366-6877
    6am – 5pm M-F PST
    Technical services: 877-278-2311
    6am – 5pm M-F, 7am-12pm Saturday PST

  220. i sealed a slate floor using aqua mix (enrich n seal). i did not towel it off now i have white splotches were water hits. we used aqua mix (sealer and coating remover) it did not work. what would be the best prduct to use to remove the sealer to some what start over? some say the tile should have to come back up. but that is the last thing anyone would want to do. it is 16 x 16 tile the roughest slate and porous you can buy.
    thanks scott

  221. We just had Golden Green honed slate (India) installed on shower walls. I loved the rich, deep look of the stone. Then, the installer grouted it with a dark grout prior to applying the enhancer/sealer. Now it looks like it was rubbed with black shoe polish! Is it possible that the dark grout color affected the stone, or is it just that the enhancer/sealer makes it a lot darker? And is there some way to get back to the way it was before? Thanks.

  222. Hi Scott,
    To find out for 110% sure, I’d call AquaMix at their toll-free number. Copied from their website: Give us a call at 800-366-6877 6am – 5pm M-F PST Technical services: 877-278-2311 6am – 5pm M-F, 7am-12pm Saturday PST

  223. Hi Kathy,
    I’m guessing it was the enhancer/sealer that was used – hopefully he didn’t get the grout smeared on the slate. The only way to get it back to where it was before is to strip (I know, I know……) and use a sealer on it that won’t change the appearance of the stone. Take a look at the products at and you’ll see what types of products are available and what they do (or don’t do!). I’m not say you have to use their products, other manufacturers have similar products too. I would have thought that the installer would have advised you that the enriching sealer would change the color of the stone.

  224. I have sealed a slate floor with Golvpolish for a nice shiny satin finish. I am now putting a slate floor in my hall and want to know if I should clean and seal the tiles before they are laid. What do you think ?

  225. We have recently applied a hard wax oil to our chinese slate kitchen work top, on the advice of the slate supplier. We don’t like the result at all – dark and shiny with the slate colour and character lost.
    Is there a way of removing this product?
    Mary Ann 17 February 2009

  226. Hi Mary Ann,
    I’m sure one of the products from would work. I would presume that what was applied to your slate was safe for food? There aren’t many products that are food grade safe, much less one that wouldn’t change the color of your slate as the oil is literally absorbed by the slate because slate is porous.

  227. We have just installed 16×16 black Brazilian polished slate. The sales lady recommended/we bought oil based Sparks sealer. We advised her we wanted a matte finish only. The installers applied per directions probably heavy 1.5 gal at 720sq ft.
    Now it has a bright shine that appears almost reflective.
    Can we use a product to bring it back to a matte or even satin finish?
    Thank you.

  228. Hi J.T.
    I’d call the company you bought the slate from and tell them that you are unhappy with your shiny floor when you specifically stated that you wanted a matte finish. They should have to take care of that. Believe me, they’ll want to make you happy.
    IF you really want to do it yourself, check to see if Sparks makes an oil-based matte sealer. If they don’t, then ask them to recommend another matte product that will work over your current glossy finish. You must use an oil-based product, if you use a water-based products you’re just going to have a mess.

  229. Hi…I bought some stone tech bullet proof sealer and stone tech enhancer pro from a place going out of buisness. My question is, should i enhance first then seal, or can I just seal with the bullet proof sealer?

  230. Does the sealant get absorbed by slate over time? Our builder said he sealed the slate (in our entire downstairs) but it doesn’t look or act like it (the slate stains, powders and even chips). Can you recommend a good sealer that will make the floor easy to clean (food really sticks to it now)?

  231. I am about to finish a cement floor with tile. This floor has a history of cracking tiles. Which would resist cracking better, ceramic tiles or natural slate tiles?

  232. Hi Sharon,
    How long ago did the builder do your floor? I’m concerned about the mention that it ‘powders’ – is it a white powder. This concerns me because it could be something called ‘efflourescence’ – which happenes when the floor hasn’t been sealed properly – especially from underneath.
    If there’s any chance of the builder actually giving you a warranty for his work, I’d have him come and take a look at it and clean it, possibly treat for efflourescence and reseal it.
    There are products you can use yourself, I’d recommend going to to look at the different products for slate flooring. I’m not saying that you have to buy their products, but it’s a very good site for explaining the purpose of each product.

  233. Hi Marion,
    I would think that a good hard ceramic would resist cracking better than slate. Another concern: What is causing the cracking of the concrete? Whichever product you go with, you real need to seal that concrete (moisture barrier) and seal the bottom of flooring before it is laid to prevent damage later on.

  234. hello flooring lady, i had a natural slate floor put down 5 years ago, i love the floor as i have kids and a dog but as soon as i ve mopped it it goes patchy and looks dirty, i ve impregnated it time after time but after a few weeks it looks dirty and scruffy, i so wish it would stay shiny looking, please please please help
    thanks emma x

  235. I have slated tile and after cleaning it you can walk across it and your socks get a gray dingy color and it’s hard to get out of your socks. How can I stop it? What do I need to do? Thank you so much for your help.

  236. Hi Emma,
    Your flooring sounds like a good candidate for stripping. I would suggest that you look at the products for slate flooring at AquaMix so that you can see what types of products are available and what they are used for. I’m not saying that you have to use these products (they are very good though!), but they have good descriptions.

  237. I have nature unsealed Green VT slate
    already down for 8 years and I did seal the white grout lines when new. Now, I would like a glossey look. Currently scrubbing the foor and grout lines with spic/span with a semi-hard bristols to get clean enough to start the process of clean looking grout lines and a more glossey looking slate. Should I reseal the grout lines first and a sealer on the slate tiles also?
    Thank you

  238. I am planning on have slate installed in my kitchen. My tile guy recommended that I put a coat of lacquer over it to seal it. What can you tell me about this option.

  239. Hi Izzy,
    I wouldn’t use laquer. Please check out the products for slate at AquaMix. You don’t have to use their products (though they are good!), I just use them for reference because they do a good job of showing products for a particular type of flooring, and explain what each product is for. Good luck!

  240. Hi, Ive inherited a slate floor in the kitchen from a previous owner of the property. It looks dirty all the time and patchy. Is there anything I can do to rectify this?

  241. Hi Ann,
    Could you clarify what you mean by “patchy”? Head over to and look under their Slate section for products for slate flooring. Here you will find info for what to use on slate and why. At least that way you can see if any of the symptoms your floor has match products that would be helpful to you. Not saying you should buy their products (though they’re very good!), there are other manufacturers out there as well — their site does an excellent job educating the consumer. ;~)

  242. Hi, In some places it looks almost greasy, then theres darker and lighter patches and also looks dirty in some areas…..

  243. Hi again Ann!
    It sounds like it might be time to strip and re-seal. It sounds like the floor wasn’t maintained properly over the long-run, resulting in more wear to the areas that get more foot traffic. I’m betting that the places that look ‘almost greasy’ still have quite a bit of sealer left and will repel water (hopefully it’s not really grease!), whereas the other areas have differing amounts of sealer left. There could possibly some some areas of the slate that are lighter in color naturally, but I’m guessing that they’re also appearing lighter because they have no sealer left on them. Keep in mind too, that when you strip and re-seal that the slate will look different. Once it’s stripped, the whole floor will probably appear lighter, then will look darker again once you’ve applied the sealer. I can’t promise that the color will be uniform as it depends on the natural color of the slate to begin with.

  244. Hi Marge,
    What is the patio made of? Is it a concrete slab? If so, you should seal the slate on the bottom before laying it. You will then need to seal the top as well to help make it easier to clean up messes when grouting. You can also just seal the slate on top and bottom first before laying it down. I would suggest that you look at the products for slate flooring at so that you can see what types of products are available and what they are used for. I’m not saying that you have to use these products (they are very good though!), but they have good descriptions.

  245. We just put slate tiles in our new kitchen. We used a product to seal reccommended but the staff at the local home improvement store. We then grouted the slate and we are having a difficult time getting all of the particles from the slate. Although each time we sponge it, it gets better. Any suggestions? Also my wife wants it to have a wet look to the slate, what product would you reccommend? Thanks

  246. I have slate out on my open back porch and after the first winter in our home it looked dull so I put a seal on it 2 days ago and it is still sticky. did I do something wrong?

  247. Hi Spencer,
    You can keep working on sponging it off, there are also products made to help. Check out the products for slate at — they also carry products for sealing that have a glossier finish. Keep in mind, I’m not saying that you have to use these products, but it’ll give you a good idea of what type of products to look for at least.

  248. Hi Linda,
    It sounds like you used the wrong type of sealer for what was already on the slate. If you mix water-based products with chemical-based products, you get a gooey mess. I’m afraid you’ll have to strip and re-seal. :~(

  249. I know you’re the “Floor” Lady, but I want to install slate on my wall in the kitchen. Directly on sheetrock, is that possible? And, since this slate has been in storage forever, and is no longer in the original boxes, how can I determine where it came from?

  250. Hi Ms. Fran,
    Yes, I’m the Flooring Lady, not the Wall Lady. Just making a somewhat educated guess, but I wouldn’t think that drywall is strong/stable enough to apply slate on – I would think it’d be better to adhere it to wood, whether it be plywood, particle board or tile board (hardbacker). Some slate has special characteristics to help you figure out where it came from, but chances are, since the original boxes are long gone, you won’t be able to figure out the origin.
    Be sure to seal your slate well – look at for products that are formulated for slate flooring – it’ll also be good to use for walls.

  251. Dear Floor Lady,
    Our 22 year old quarry tile floor needs stripping and re-sealing. We are going to have it professionally done and wonder if you know the approximate cost per square foot that we should expect.
    Thanks, Candace

  252. Hi Candace,
    I can’t really give a good estimate – it will depend on the products that are used, how much product is used (please don’t let him skimp on the sealer!) and how much the contractor figures his time/labor is worth, which can vary greatly depending if you’re in a large city or rural area.
    If you feel like you want to tackle this yourself (and you can!), check out – they have great products for stone and explains what each is used for so you can figure out if it’s what product(s) you need.

  253. I have slate tile in a shower that was sealed when installed. A year later now, it has started to look hazy and white. I would like to put a finish on it that will keep it looking dark like it does when wet. Do I need to strip the sealant off before applying a top coat? And if so, what product do I use? Do I follow your advice given for flooring, or is it different in this application? Thank you for any advice you may offer.

  254. Hi Angie,
    What do you think is making it look hazy? Is it possible that it’s from soap residue? What do you clean it with? It is possible that it needs stripped and resealed – it could be too that the sealer is already worn if the sealer was applied rather sparingly. For someplace used as frequently as a shower I would have sealed with the recommended number of coats and then another coat or two.
    Anyhoo, I would recommend AquaMix products for slate flooring ( They also have a stone enhancer, which usually makes a floor darker. Sometimes the sealer alone will make it look darker. If you really love the wet look, you would probably want a high-sheen (glossy) product, but this can also be problematic as it is more slippery when wet.

  255. Can I apply polyurethane on slate tiles? I installed 12 x 12 slate on my front porch 2 years ago. I sealed them with a priduct from Lowes that guaranteed a “wet look”. It didn’t. When they are wet the color shows and they are beautiful. I have applied polyurethane on some test tiles and they great; wet all the time.

  256. Hi Alvin,
    Yes, you can do this. Are these spare tiles that you tested on or tiles that are already on your front porch? If these were spare tiles, then you should probably remove the previous sealer, unless you know it’s the same type of sealer (water-based for example). If they are different types of sealer (oil-based and water-based) then you will wind up with a sticky gooey mess.

  257. The tiles are outside the railings (not a noticable area) and it looks great. It has been there for 48 hours and is dry not gooey. On another subject; what can I use to remove the finish on pre-finished Bruce 3/4″ Hardwood floors. Thanks for the response and advice.

  258. Hi Flooring Lady. I am installing some Brazilian green slate, and I have tested the impregnating sealer (lithofin) on a few tiles first, but every time I get lines left from where the sealer has been applied. The bottle says you must remove excess sealer from the tile before it dries but if I do this it leaves marks. The tiles are honed. What is the best way to apply the sealer and is it best to use a roller, cloth ??? Thanks, Chris

  259. I am waiting to hear the answer for Chris. I have installed Brazilian slate, gray. we have sealed it before it was put down just to protect it. What is the best sealent to use? I will seal it again after grouting. We have 1/8 ” seams. What kind of grout should we use, sanded or unsanded? I would also like to know if purchasing a steam mop will help making cleaning easier. I am so afraid that I made a mistake and should have put down ceramic tile due to stains that can occur.
    Thank you for your advice :)

  260. Hi Audrey & Chris,
    You can view their products for natural stone at Lithofin’s website, and click on the product you used to view their recommendations for what is best to apply the product with. They do have more than one sealer.
    Audrey, the “best” sealant to use depends on what you are trying to achieve. Actually, I recommend products made by Their website is wonderfully user-friendly and does a good job explaining what each product is for and when/if you should use it.
    Protecting your flooring after it’s been put in will help to keep stains from occurring as long as it has been sealed well and properly maintained. I don’t have a ‘preference’ for grout, though I generally tend to use unsanded the most. Steam mops can be a good thing, but in general, just using a weak vinegar/water solution (1 part vinegar to 15 parts or more water) and a microfiber mop does wonders.
    If stains should occur, there are products to remove those too.

  261. How often do we need to seal slate and travertine tile? We remodeled our bathroom last year and are just trying to figure out when it is necessary again.

  262. Hi Vanessa,
    It depends on how well it was sealed the first time. Basic rule of thumb is every one to three years. So long as water still beads you’re fine. Don’t be stingy when you reseal either – use 2 or 3 coats, letting dry completely between coats.

  263. Hi Flooring Lady. My husband and I just installed slate tiles in our foyer from a nearby quarry. We sealed them first before grouting to get the wet look and to keep the grout from adhering to the surface. Everything was going smoothly, that is until after we grouted. Once the grout dried we noticed that the color of the grout which was supposed to be almost a dark black dried to a light gray color. We followed the manufacturer’s (Laticrete) instructions to the T and don’t know what could have gone wrong. I am aware of efflorescence but I’ve been doing a lot of reading on the internet and it seems Laticrete’s grout developing a few shades lighter is a common problem. I’m thinking of using a colorant to fix the problem. Do you have any suggestions?

  264. Hello. We recently remodeled our home and had slate put in our kitchen. It was beautiful until the first time I cooked in our kitchen. There are oil stains that were absorbed by the tiles. Any idea how I can get the stains out and what can I used to seal them so that they are not porous anymore? The guy who installed it swore he sealed the floors. Thanks.

  265. Hi Shelly,
    Have you tried sealing the finished result? Or even sealing just the grout? Maybe the sealant will give the grout the same wet look and bring the color to a darker shade.

    This doesn’t sound like efflorescence to me. I think it’s an issue of sealed vs non-sealed surfaces, as well as the grout drying lighter than “promised”.

  266. We bought a condo with slate floors already installed, but instead of grout they were set into cement.
    We sealed them when we first moved in and then washed and used “mop and glo” ever since.
    The cement is very unsightly in two of the rooms while in the third the color matches the slate and is fine.
    Is there anything we do to “clean” or “color over” the cement lines in the other two rooms?

  267. Hey there flooring Lady.
    I just installed slate tile in a new shower. We selected Piedra Pizarra Multicolor tile. 10 mm Calibrada from India. After only one week of use, I am noticing what looks like rusting. I have not sealed this tile yet. Is that normal for it to rust like that, will i need to re-grout it or will it clean off. I am planning on using a enhancing sealer on it, but I don’t want to seal the rust into it.

  268. Hello Elaine,
    I don’t have any experience with cement used as grout so don’t know what you can do for it. Your best bet is to probably contact a cement contractor and ask them how to deal with the thin concrete lines.

    Good luck. Please let us know what your solution is.

  269. Hi Daniel,
    I’m not familiar with that material, but it sounds to me as if minerals in the stone are reacting to the water. If you don’t want it to continue hurry with the sealing. You can try to scrub the rust-color away before sealing it,
    but be sure to not use that shower between the time you start cleaning the rust and the sealant curing so that you quit aggravating the staining mechanism.

  270. Unfortunately they are not “thin” concrete lines, but uneven “thick” ones– a real amateur job done by previous owner. But I thank you for the suggestion and I will follow up and let you know if I find a solution. I really appreciate your responding– thank you very much.

  271. Hi Flooring lady…I just installed slate in my living/dinning room and want the wet look, not necessarily glossy–just wet. What do you suggest I use as sealant to protect and achieve the wet look?

  272. I am confused, so many other people say to clean off the excess grout as I go but you say i should wait a week. Is this correct?

  273. I should have explained my project, I’m sorry.
    We purchased a home that was owned my people that held their heads high, because they obviously never looked at the floors and linoleum is in the kitchen. We have unique decor tastes and have decided to lay India multi color slate tile (blues greens and reds) in the kitchen. It is sub floor, Clean tiles / let dry and I plan on using cement backer board, applying water based poly slate tile penetrating sealer to the tile while it is in the dry run, then setting the tile using thinset with acrylic or latex instead of water, Grout tile by using latex grout with water based poly slate tile penetrating sealer instead of water wiping excess off as I go, let dry for a week, clean the floor and use water based poly slate tile penetrating sealer again.
    I am going for the wet look
    That is my plan using a lot of your advice, do you see anything that I have over looked; being this my first time I want to be sure I have every step planned out. (I am so excited)
    Thank you so much

  274. Hi,
    We had our slate flooring installed 15 years ago as part of our new house. The slate was sealed after it was laid and we were told that it would need to be resealed. Over this period of time, the slate has lost it’s wet look and we now think it may be time to reseal. Would you have any concerns about resealing this floor.

  275. Hi there,
    We are about to have a brazilian slate floor installed. The sealer says dry in 48hrs. Do we have to seal before the grouting is done? (we don’t really have the tiler for that long).
    Can the floor be laid and then grouted or will the grout stain the tiles?
    Many thanks, Lesley

  276. Hello,
    I just installed Indian slate tile on an outdoor/patio bar i built. I am getting ready to seal with a semi-gloss sealer. My question is what is the best way to clean the tile. They suggested i seal with 1 or 2 coats prior to grouting to make clean up easier after grouting. Do i just use water to clean or a stone cleaning product.
    Thanks so much

  277. I have slate floors. When I bought the house several years ago it had a wet glossy look. I no longer have that look anymore and wanted to know if I can put the water base poly on the floor to give it that look.

  278. I have 2 cm smooth Black slate slab to use on an entry hall table. What do I use to seal it with? Someone suggested to keep mineral oil on it; which I believe has already been applied. Should I do that and can a sealer now be applied over the mineral oil for better wear? Will any type of sealer protect from scratches?
    Thanks so much

  279. I have a slate bathroom. The tiles is getting a white look – what could the problem be and how can I rectify this?

  280. Hi Sandra, There are 3 potential reasons for the white residue:

    1. Depending on what level in your house the bathroom is you may have moisture coming up from beneath the tile, probably because there’s not a good moisture barrier underneath.

    2. The floor was inappropriately sealed/polished, possibly with products that were not created specifically for slate/stone flooring.

    3. It could just be time to strip and reseal.

  281. Hello,
    We just installed a Vermont, Grade A slate floor throughout our mudroom, laundry room and foyer. We did not seal it prior to installation. The installer indicated that he did not recommend sealing it, but would if I wanted to do it. What do you recommend? I like the non-gloss, non-shiny look as we have a Vermont slate stone masonry fireplace that is natural-no seal and is very close to the new floor.
    Thank you.

  282. We bought a house that has slate tile installed in the entire downstairs. All I can say is it is dirty. I love the look of the floor but nothing seems to get it clean it is will sealing the floor help resolve the problem? What do you recommend?

  283. Hi Dawn, I would seriously consider going ahead and sealing your slate for since it sounds like a pretty high traffic area that will be seeing a lot of dirt and stains. Sealing will definitely help protect the beauty of the slate.

  284. Laid about 700ft of slate i did not seal it before putting it down should i seal it before grouting? I was told that if i seal it before grout and the sealer goes into the grout lines the grout will not adhere to the slate properly? i want to use an enhancer sealer i looked into the sealers from stone technologies do you know anything about there product? they sell a lot on ebay talked to the tech guy at stone tech he said to use there sealer and then spray the enhancer over the sealer just does not sound right to put enhancer over the sealer i guess that would mean it is a topical enhancer would that be durable?It is an oil base i was told, is that better than water base?thanks for any help you can give

  285. Hi Ted, you need to allow the grout to cure for a week and then applying the sealant will be fine. I always recommend using Aqua Mix as a sealant. I prefer the water based sealants myself.

  286. I have stripped my black slate floors several times since they have been installed. I have used products that was avised for slate floors. Sealed and finished time after time but still have the the same problems. Problem. If you spill anything on the floor it eats of the product even water. The last product I used was Tile Guard. We had a buffer and stripper to take off all the old product from the slate. The slate was at the dull white state before we sealed it. We let it dry over night and then put on the sealer. The sealer was left to dry 24 hrs. Last, we put a gloss finish on. We did everything like we were told and I stll have spots where it looks like we are down to the unfinished slate. Help!

  287. Hi There,
    I’m in the process of having Brazilian Slate installed in my bathroom. My installer wants me to use Aqua Mix Stone Enhancer on the tiles before he grouts them and then put another coat on once they are grouted. He claims the excess grout comes off much easier with this process but I’m told that this particular slate is so dense that it will be easy to clean the tiles after grout has been applied.
    The rep. at the slate store told me to wait until they were grouted and then use Enrich’N’Seal. He also said if I wasn’t happy with the mat finish then in about 6 months scuff the surface up and apply a gloss finish from Aqua Mix.
    Thanks for your help.

  288. Pat,
    1-2 coats are sometimes required to achieve the glossy look you are wanting. It also depends on the type of Finish you are using.
    Older tile should first be thoroughly cleaned with a Cleaner / Degreaser, then let dry for at least 24 hours.
    Don’t let the finish pool too much or it won’t dry properly. Work very quickly and always off of a wet edge to avoid lap marks. Allow about an hour drying between coats. Apply 1 or 2 coats. Do not apply in direct sunlight or during very hot weather. Strong wind or drafts should be avoided as it may not dry clear.
    If you followed the instructions clearly then I would call a local professional to help you achieve the look you are wanting.

  289. Lori,
    I believe it is a personal preference that you would have to make. What do you want your tile to look like. Matte,glossy, easy to clean finish. Perhaps a second opinion from a professional installer would ease your mind.

  290. Hi, we are looking at purchasing slate for our main hall, kitchen and dining room. We are looking at purchasing it from Olympia Tile in Toronto. Do you know if they sell the hard slate from Vermont or Canada? Do you know somewhere where we should purchase our slate from? I am worried about splashes from butter and oil while cooking. Will these marks stain even after putting on a sealant? What do you suggest as a floor cleaner? Thanks very much for your help. I found your website very helpful.

  291. Jane,
    Contact Olympia and inquire if the hard slate is from Vermont or Canada. I prefer not to recommend a place to purchase as suppliers change inventory. It is best to inquire personally. In regards to slate it is considered extremely durable, slip resistant, and stain resistant (more so with a penetrating sealer). I would consult a local professional and retain their opinion as well. Good Luck Jane!

  292. We just installed 100 sq ft of Indian slate on our floor this weekend. It has not been grouted yet and I want to clean the tiles before applying the sealant – then we will grout. Can you tell me EXACTLY what I should clean them with? Just hot water? Also, would you suggest I hose down the remaining 1400sq ft prior to installation to aide in cleaning it after it’s installed or will that affect it’s adhering to the mortar?

  293. Hi Gabrielle, Just cleaning with a mild soap and warm water will be fine. I state in my article the following in regards to prepping the subfloor for installation: “The preparation needed before installing your slate floor tiles is to clean the subfloor where the slate is to be installed, clean all slate surfaces, and let them dry thoroughly before applying two coats of the penetrating tile sealer.”

  294. I have a slate courtyard and front porch. Over the weekend I powerwashed both. Do I need to seal and if so what do I use?

  295. Annette,
    One more thought, if water still beads up; it probably doesn’t need to reseal, although given the location it does receive quite a bit of traffic and could probably benefit from sealing.

  296. HELLO! I have gotten two suggestions for sealing my slate floor from two different flooring guys at our local home improvement stores. HAD TO REMOVE THEM BOTH – STICKY, STICKY, STICKY. Lots of hard work for nothing. Please give me, if you will, a brand name of a sealant. I would be forever grateful!! Thanks, Joan

  297. Hi Flooring Lady!
    We’ve recently moved and now have a beautiful (but unsealed) slate bathroom – slate shower, slate floors throughout and slate-accented bathtub. I don’t have any maufacturing info but the slate looks Chinese in origin (rusty yellow and gray-green). I love the natural look but I’m concerned about the shower – having it unsealed has made it hard to clean and prone to water stains in one area. There are a few areas that have grown a little mildewed and when I tested my usual mildew cleaning method of baking soda and vinegar/water solution it seemed very harsh on the tile as my scrubbing solution turned muddy colored!
    How should I clean unsealed tile and grout?
    I’m thinking of only sealing the shower – how would you recommend I approach this task?
    Thanks so much!

  298. Charlotte,
    I state in the article “To seal or not to seal? Go for it with a penetrating, water-based slate tile sealer and enjoy your natural stone floor for years.”
    There are finishes that look natural after application. I would consult with a professional in your area to determine which penetrating, water-based slate tile sealer is available in your area.

  299. Hi Flooring Lady!
    We bought a house lasty August that is now 3 years old with both ceramic and slate tile. I am fairly sure that none of them were sealed. Is it to late to try to seal them, and do you have to do something different to the grout joints beside what you would put on the tile.

  300. I have sealeed my black slate floors which have not been sealed in years and they are a high traffic area in our office.
    We have put on a solvent sealer that was to penetrate and dry with 24-72 hrs. It is now at almost 72 and still not dry,, very sticky and went to walk on it and it has left a foot print everywhere!! What can I do to remove this foot print if at all???? Do I have to put another coat of sealent on the floor or can it wash off with a cloth?
    Thank you

  301. The entrance to our home is slate tile which I assumed was sealed(has a glossy dark look to it) 37 years ago when the home was built. We have lived here 32 years and I have scrubbed cleaned and waxed this floor keeping it shinny as it was when we moved in. The sealant started to break down on the grout lines by the doors and I see dark streaking thru the tile. I have tried to strip it using different products and a steamer, what a job. Is there anything I can use safely to either get it’s to it’s natural look or just clean and reseal?

  302. Thanks for your reply, I have spoken to professionals about this floor they all want to replace it. I really don’t want to it’s a beautiful floor that is securely in place after all these years. There is no water damage I just need to remove the sealant at this point do you have any suggestions as to what I can use myself?

  303. Elaine,
    I am unable to assess your situation specifically as I am unable to see the tile and the issues that have your local professionals concerned. Perhaps you should ask specifically what those concerns are and how they can be addressed without replacing the tile.

  304. Dear Flooring Lady,
    We currently have a solvent-based sealer on our 485 sq ft. slate floor installed in 2001. We’re getting bids on stripping and resealing it. One company said they could strip and seal using all water-based products. Another company said the only way to remove the solvent-based sealer is with a solvent-based stripper. Who is right?
    Thanks so much!

  305. Barbara,
    I suggest first getting yet another opinion. Then I’d check with products like Simple Orange, or other orange-based products that have the reputation for stripping things safely to see if that could work.
    But once it’s stripped I highly recommend going with water-based because they are more environmentally friendly and won’t offgas the same way solvent-based products will — and it’s important to keep air quality good.

  306. Can I use a penetrating sealer on my slate floor followed by a semi gloss sealer and finish? I bought some Dupont semi gloss sealer and finish but nowhere does it say penetrating, as you recommend.

  307. I’m getting ready to do a slate tile shower and bathroom floor. The guys at home depot said it’s a bad idea to use slate in areas that have water in them. My boyfriend assures me it will be fine. Should I be worried? and what would the best type of sealer be for slate in the shower?

  308. Monica,
    Any product you use to finish your flooring make sure it’s made specifically for your stone!
    I’d be a bit leary of using it if it doesn’t say penetrating as it may not be!
    Call Dupont and ask them if you are unsure, better safe than sorry and if not try Aqua Mix, they make a penetrating sealer.

  309. Brittany,
    Slate has various qualities-some hard or soft. If it is soft it would be more susceptible to water damage.I would also suggest you making sure to use a reliable sealer and finish. Aqua Mix has a variety of sealers and finishes to choose from!
    I would also go back to home depot and ask them to explain in a bit more detail their concerns, perhaps it is the quality of the slate that has them concerned.

  310. We just laid 2500 SF of random slate on the cement pool deck. We did not seal before grouting. It’s nearly all grouted and my installer wants me to clean the entire deck with an orange-based cleaner. But I think those have oils in them, and then will that prevent to sealer from penetrating when I do that in a week? Many thanks for your time!

  311. I hear you aren’t supposed to walk in bare feet too much on slate tile because the oils in your skin can mar/damage the tile. If the tile is fully sealed, does that eliminate this problem? We tiled our bathroom in slate and applied a penetrating sealer, but obviously we are in there in bare feet a lot.

  312. Greetings, We installed a slate floor in our kitchen several years ago and did not seal it. It needs to be thoroughly cleaned and sealed. What is your recommendation? Thanks! Jeri

  313. Jeri,
    I suggest cleaning the slate and the grout with a neutral pH cleaner. I recommend StainSolver . It is very important to use a neutral pH cleaner when installing as well as minimal water. You don’t want that water to get under the tile to the subfloor.
    Once the floor is clean, it should dry for several days before sealing. The sealers work best when they can penetrate into the slate. Aquamix has a variety of sealers and finishes to choose from.

  314. I’ve installed a small floor 6×3′ in a guest bathroom. The flooring is 2×2″ slate tile (India). I made the mistake of using finishing seal instead of penetrating (TileLab). I applied 3 coats of the seal and laid the tile down into the thinset bed yesterday.
    I have not grouted yet and would like your opinion on what my next move should be.
    Should I mix in penetrating sealer with my sanded grout, grout the floor, then after it dries, strip the finishing seal from the tiles and reapply a penetrating seal to the whole floor?
    Or…should I remove the finishing seal prior to grouting the floor, then apply penetrating seal to the tile, then grout.
    Or…something completely different!
    Let me know what you think, thanks!!!

  315. I installed a slate tile floor and was told that I could seal the floor and the grout after I grouted. Is this OK or should I do something else.

  316. I just put a slate floor on my outside patio and the slate is from India. I purchased at Home Depot and they gave me some sealer to apply before I grout. I have applied the sealer and now all the tile has a white cloudy look to it. I’m not sure where to go from here, do I need to remove this sealer and if so, how? How do I prevent this from happening again?

  317. Randy,
    Moisture trapped in the sealant would cause the white cloudy appearance. If the moisture is temporary and is the cause of the white cloudy appearance you would need to strip the sealer off to allow it to dry. Not knowing the manufacturer of the sealant contact the manufacturer of the sealant for the proper method of removal.
    If the white streaks in the sealer is caused by moisture, you can try to remove them by taking the same sealer and apply it over the tile and let it dry for several minutes. Then immediately get a dry lint free cloth and buff the tile dry. You can see if that will take the white streaks away.

  318. Just had a beautiful natural slate patio installed. 24 hrs after grouting, SGM clear penetrating sealer (Southcrete 901 waterbased) was sprayed over the patio. It has left a horrible white film in a spray pattern. The tile store says the sealer was applied too soon and incorrectly. What product can we use to remove the sealer?

  319. I installed indian slate tile around my bathtub walls. It turned out beautiful, however even after sealing it with two different sealers, the color from the tile is running down the wall and staining the tub. What can I do to fix this problem? Thanks in advance.

  320. We recently had California Gold slate installed on both bathroom and shower floors. The slate on the shower floor is ‘bleeding’ a rust color and, in turn, staining the grout. The manufacturer and installer are going back and forth to rememdy the problem; however, without success. They say they’ve NEVER seen this before. I’m concerned they may make it worse. They have suggested dyeing the grout versus tearing it out and putting in a different tile altogether. What do you think about dyeing the grout a darker color? Will this solve the problem? Will this discolor the slate? And, what is causing the slate to rust?
    What product/sealant would you suggest for a low-sheen finish on the slate? Thank you for all your help.

  321. I have an original blue slate floor (Vermont?)in the hallway of my 1968 house. The floor was covered with with 40 years of wax buildup and had cloudy stains. I stripped the wax off with AquaMix stripper and I now have the original unshiny slate color which I kind of like.
    What is the difference between sealers? I see there are color enhancers which I am afraid to use since the floor already has reds, blues, greys and green and the enhancer may make it too colorful for the small space. Are there non-color sealers that would not make the floor too glossy? Thanks.

  322. Nick,
    I am not sure if this could’ve been caused by using the two different sealers. I would not apply more of either until it is thoroughly dried. I would then check with the manufacturers of the sealers to find out what they would suggest before doing anything else with the tile.

  323. Julie,
    Hi. Iron oxide (irons and metals in slate) is common with slate. When installing, the tiles
    need to be washed with water and agitated with a brush. Then left to dry well. This cuts down on the color bleeding into your grout.
    Dying the grout may cover up the stains, and if it is done by a professional, I would think they would know how to protect the tile from being stained as well. Then being resealed according to the manufacturers instructions and recommendations on the sealer should be safe. I personallly recommend Diamond Coat Varathane Polyurethane water-based poly.
    However, if you are working with the manufacturer and the installer, they should be able to advise you of the best options in your specific situation.

  324. I have a slate tile floor over which had been placed a seagrass rug with it’s own rubbery type backing. When it came time for the rug to be replaced I was horrified to find that the backing had somehow fused in many, many areas with the slate–it’s almost as if it melted into the slate and left these awful hard-as-rock scaly deposits. I’ve tried different things to remove them but short of using a hammer and chisel (which I’ve done), that seems to be the only remedy. Do you have a recommendation and if so, if I seal the slate in the future, will that help prevent a rug pad from doing this again?

  325. Karin,
    I would encourage you to call the manufacturer and ask them the best way to scrub those clean. Harsh chemicals would be unhealthy and possibly damage the floor.
    After the slate is sealed, in the future, this should not happen again. The backing may stick a little, but shouldn’t be as hard to remove.

  326. I am currently installing indian slate 12 x 12 tile thoughout my entire home. I am interested in a low sheen sealant that will enhance the colors. What brand of sealer do you recommend. I tried the links offered on this page, but have not been successful in locating Diamond Coan Varathane Polyurethane, if that is what you would recommend for this application. thanks.

  327. A year ago we bought a house with slate flooring. I do not believe it has been sealed. We clean it every few months with some type of floor cleaner. It never really gets clean. Lately we have experienced a black gummy hard scumb on the tile and it seems to be making the file break up in fine pieces leaving a large whole in the tile. Any experience with this and any suggestions on what to do? Thanks, David

  328. Hello,
    First I must say that your article is very interesting and I got some valuable information from reading it.
    The concern that I have is about slate roofing tiles, that came from China. I was wondering if you could help me, because the problem that we have is that the slate roof has been installed about 3 years ago. Over that time the a lot ( and I really mean A LOT) of slates have pealed off and some are just falling apart. To me it seems that the weather conditions (Chicago) are damaging the slates. Do you think that if we applied penetrating sealants it would stop the slates from falling apart. I would really appreciate if you could recommend a product that we could use on the roof slate.
    Thank you

  329. David,
    I have not had this experience, but it does sound as though the tile needs to be sealed.
    I would try to clean it with a mild soap and water. And, maybe check with the manufacturers of your current floor cleaner, and see if they have a solution to the black scum that you getting.

  330. Hello,
    my kitchen floor is slate. The surface is rough which makes it difficult to sweep out crumbs, foods or dust. Any solution to make the tile surface smoother for my cleaning job? I don’t believe my floor is sealed. Will many layers of sealant help? Thanks.

  331. 40 years ago in an effort to save $, I set garden variety large slate pieces in mortar for our kitchen floor. It is uneven + – 1/4″ and the mortar joints are almost black from various sealers. We are no longer pleased with the appearance. I would like to have someone resurface the floor and apply a good sealer. Is this doable? Where do I start?

  332. Tom,
    Stone floors can have the old sealer removed and be redone. However, you may need to tear the floor out and redo it to make a 1/4″ difference level. There may be a professional installer in your area who you could ask to take a look and offer suggestions.

  333. I just last week installed my first slate floor.
    I sealed it with two coats of penetrating sealer. I was not aware of how soft the tiles are. The dog scratched one of them with her nails today. What can I put on them, if anything, so that they will not scratch so easily?

  334. Hello. We have a black vermont slate kitchen floor, which was installed about a year ago. We have had it sealed and stripped and resealed 5 times by professional floor care companies and, yet, the floor will not maintain a seal. Each time it is sealed it is fantastic for about 1 month and then we notice that water no longer beads on it, it begins to stain, and when we wash it with a rag the rag becomes black with residue/color from the slate? The flooring company has used both Aldon Chemical products and Aqua Mix products in attempt to fix the problem. Nothing has worked! Any suggestions? Thank you.

  335. We have a slate floor in our bathroom. 9 months ago I had a baby and hadn’t really cleaned the floor super good for a while. When I cleaned the floor it seemed very dirty, especially behind the toilet. Then I realized that it wasn’t dirt that was coming up, but it was the slate dissolving. The kids aren’t very good at sealing the shower with the shower curtain and I think water has penetrated the stone. Should we reseal the floor? or do we need to replace it?

  336. Jo,
    I would suggest calling the manufacturer of the flooring you have and ask what is best to seal it with.
    It is possible that the floor care company is not using the correct sealer for your product.

  337. What is the best product and method to remove a water based topical sealer from my slate floors? The sealer has been on for about 5 years and is long overdue for re-sealing.

  338. I have had my Chinese Slate floor down for about 6 years, there has never been any heavy traffic, as I live alone, and do not entertain a lot. The color of the slate is charcoal grey, I have noticed there are some white stains on the tiles close to the wall, the shape of the stain is like a water stain would look like. I have cleaners who wash the floor every month and I have no idea what they use, can you tell me how to clean the tiles so I can let my cleaners know also do you think they would need to be resealed and if so, do I have to remove all the furniture? there is no wear and tear under the sideboards which are large and heavy and would really be a difficult job to move

  339. What kind of company do I get to come and seal my slate floor? We moved in to our house 3 months ago, I have four kids and can’t seem to keep the floor clean. Every little thing shows up. Also when walking on the floor with socks, the socks end up dirty from the slate. Not my favorite flooring. I have no idea where the slate is from either.

  340. Shane,
    If you know who the manufacturer is of the original sealer, I would call them and ask for their recommendation.
    High alkaline cleaners can remove water based sealers, but I do not have a specific product recommendation.

  341. Jill,
    There is an article on Stone Floor Care that will help with the cleaning suggestions.
    As far as the sealers, if the sealer is damaged it should be resealed to be protected. The furniture would need to be moved if the sealer was being applied to those areas.

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