Installing Stone Flooring

Stone sealer - sealant creates a barrier on the surface of your stone floor that repels liquid and keeps spills and water marks from penetrating and damaging your stone floor. This treatment is the perfect finishing touch to any granite or marble installation works. This process is a must for the protection of all natural stones.

Dear Floorlady,
I am planning an addition to my home in Central NY state. One part of the addition is an entry/mudroom, unheated but enclosed and insulated. The other part is a screened porch, open to the elements.

My builder is planning a concrete pad for both. We have lots of options for flooring but I'd really like stone to match the fieldstone fireplace and drystack walls around the property.

I have so many questions. Does it make sense to put stone on top of concrete? Do I mean concrete or cement? Does the concrete/cement have to be laid on a slight grade? Will moisture cause the floor of the porch to crack and the stones to heave or become loose? Where can I find exact instructions on how to do this...there are a few stone masons around but I'd like to understand as much as possible before talking to them. Do you recommend slate or flagstone instead of fieldstone? If fieldstone is OK, can I use rocks I find myself (we have lots of rocks around here and, strange as it may sound, gathering them from creekbeds is a lot of fun....the local farmers call us "Rock Freaks".)
thanks.

Hi Karen!
Wow! Lots of questions! ;o)

Yes, it makes complete sense to put stone on top of concrete. It provides something stable for the stone to sit on so that you will hopefully never have to experience 'heaving' stones.

I wouldn't think that the concrete has to be laid on a slight grade since the whole idea is to have a level floor, right? It will self-level somewhat and your builder will have tools to utilize to make it level. :~)

Slate may not be great choice unless you have a very good moisture barrier underneath - preferably under the concrete itself because concrete will draw moisture, which will ruin everything! You can really use any of the stones you want so long as you have a good moisture barrier underneath them and really good sealer & finish (multiple coats!) on top of the stone. Even the creek stone should be sealed or you'll be losing pieces/layers. In my experience there is usually layering associated with these stones.

Of course, I can't guarantee that the floor wouldn't heave/crack, but it will definitely reduce the chances.

Oh, and don't worry - you're not alone! There's lots of 'rock freaks'!

You're one smart cookie to want to know everything possible before you contract workers! Don't be afraid to utilize the site's search engine located in the upper right-hand corner and even at your favorite search engine (mine's Google!). Read, read, and read some more!

I am trying to lay a runner, which was made from my carpet on my stone stairs, which are solid precast stone. I wondered if you had any ideas for an adhesive that would be strong enough to hold the carpet on the stairs without damaging the stone. Obviously I would only apply the adhesive to small areas on the stairs necessary to hold the runner in place, but I would love some ideas...thank you!!

You could try stair rods which attach to the stairs on top of the carpet- the runner is held in place by them. I've seen them in brass and stainless -- there may be other options. This option would let you remove the carpet runner for cleaning or redecorating. There are no VOCs from glue to worry about either!

Hello Flooring Lady,
I have just completed building brick and stone (sciota blue stone treads) front steps to my home. I'm a pretty experienced diy'er and the steps look great, but have run into a problem with the landing. For the landing, I "wet-set" irregular flagstone varying in thickness into mortar. They look great but I've run into a slight problem. I graded the landing slightly away from the front door as to avoid water run-off toward the house. However, when setting the flagstone into the mortar, due to the varying level of the stone, I have had some "pooling" in certain spots of the landing. When I leveled the landing, I used the high point of each stone instead of the low point as the point of reference, which has created some natural peaks and valleys on the landing. I was wondering if you knew of a clear gloss finish which would function as both a sealer and a self-leveling agent. Most sealers that I have looked into online seem to be brush, roll, or spray on. I'm wondering if there is something that may provide up to approx 1/8 - 1/4 inch of "filler" in some of the valleys of the landing. Any suggestions?

Hi Frank,

I've never heard of any that are thick enough to act as the type of filler you need. Maybe somebody else has and they'll help us out by chiming in.

Dear Flooring Lady,
I am converting a 5x13 room in my basement into a wine cellar. I am using natural flagstone to do the walls and the floor. I have the vapor barrier and the galvanized metal lath for the walls and it has a concrete floor. I have a couple of questions since I am new to this and the guy helping me has only done brick before.
1 Do I do the walls first and then the floor? I was planning on using a 1x2 on the base of the wall that I would remove after I do the walls which leaves room for the flooring. (also doing that on the ceiling and around the door.) Is this a good idea?
2 Can I set the stone directly on the concrete floor or do I need a moisture barrier there also?

Thank you for your help.

Hi JW,

This sounds more like a question for somebody who deals more in construction since you're dealing with floors and walls. It sounds like it'd be a good topic for me to investigate/learn for myself. This part of the site will help explain about different moisture barriers.

I would think it'd be easier to lay the floor first to avoid a gap at the base of the wall, but that's up to you, especially since I don't have a clue as to any of the specifics about the flagstone you're working with.

I did a little Google-ing using this search: "how to" build "wine cellar" - interesting stuff. I think you'll find this to be very helpful in particular. Sounds like a neat project. Good luck!

I am remodeling a powder room with 24 12x12" sand stone tiles that i have put 2 coat of sealer prior to install.My question is:-"When i put the sealer on the tile i liked the look it made but after drying it when back to the original state.Is -it possible to keep that wet look?
thank you.

Marie

Hi Marie,
Yes, it is! What you need to use is a high-sheen or glossy sealer or finish. AquaMix has a wonderful line of products of sandstone flooring. The biggest thing to worry about is making sure that whatever product you use next that it will be compatible with the sealer you've already applied. Have the info for the sealer you've used readily available and give AquaMix a call - you don't want to mix products that aren't chemically compatible or it'll ruin your finish, give you an ugly finish and possibly damage your flooring. There's a toll-free number at the website.

I would like to apply flagstone to the wooden entry steps to my house. The wood is 2" x 12" and the steps are about 5 1/2" deep with space left to equalize the risers at the top step onto the Hardie plank porch. Should I use a sub flooring like Hardie backer or would mesh and mortor do the trick? Thanks

Hi Karen,
I suppose it would depend on how much reinforcement the steps already have under the wood. Sounds like they're pretty sturdy already though and I would tend to think that you'd do ok with the hardbacker (hardie backer).

Hi :),

We just started installing polished stones in our entry way. however, the color does not look as shiny as what we saw in the store and I am starting to think that they gave us a non polished stone!!! how can i tell it is polished and do you think enhancing and sealing it would help?

thank you so much,any ideas would help.......

Hi Sam,
Enhancing and sealing may help, though if it's pre-sealed you will have to strip them first and if they're not sealed, they really should be before you install them to make it easier to remove grout residue.

I would suggest taking one of your tiles to where you bought them from and comparing them. I can't tell if they're really polished or not since I'm not there. If you aren't happy with what you received vs. the store display, then by all means raise a ruckus with them!

Good products for your stone can be found at bioshieldpaint.com - good luck!

Thank you so much for letting me know what I need to do to seal my floors. I did by a product that is called pre-grout sealer. on the box is say to apply if before putting grout and I showed the product to my installers and they said it is not necessary to do that since grout will fill all the holes on the stone and that is what it is for. I am in a cross road. should i pre seal or not? I can not tell if they were pre sealed and am not sure how to remove the seal after grout and reseal again!!! thanks

Sam, what kind of stone flooring do you have? Some types of stone have little low spaces that can be filled in with grout and then sealed, but this is usually done by the manufacturer. I've also heard of a lot of people complain about the little pieces of grout popping out, most likely due to expansion/contraction, which normally isn't a problem, but like I've stated, I have heard of it here on this site.

Basically, if it's pre-sealed, you shouldn't have any problems. Easiest way to determine this is to put a few drops of water on the stone. If the stone absorbs the water, then it's not sealed.

If you have natural imperfections (little dips, pits, etc.) in your stone and this is what you like, then your installer really shouldn't get the grout in it and then seal if the tile isn't already pre-sealed. Make sure he does a thorough job of removing any grout residue so you don't get any white grout haze, which wouldn't be noticed until he seals the floor. The only remedy for this is to strip and reseal. Good luck!

Good Day!

I was thinking of using some beautiful but thick stone (1 to 1 1/2 inch thick stone on an existing patio that has a concrete base now. Is this stone to big and if not how much grout foundation do I need to put down to hold these stones in place. The area is around 300 sq feet.

Thanks so much

Hi John,
You might want to try to find some sort of patio or outdoor landscaping type site to ask this question. I should think that the stones are fine, but wouldn't have a clue as to what would be proper to set them in outside. You'd definitely need something heavier than a thin set mortar. Sorry for a lame answer, but this site is for flooring within a home - though on ocassion we can help with patio situations where the flooring has already been laid - like help with cleaning and such.

Hello,

I am planning to floor my bathroom myself and I have 3/4" thick subfloor. It is an old house with original hardwood in the hall that meets the bathroom floor(linoleum). I bought 1/2" backerboard as a (novice) thinking I would apply it to the subfloor. The problem is if I put the mortar, backerboard, and tile on the floor, I am going to have quite an incline between the bathroom and the hall. Even if I take out the subfloor and put the 5/8" subfloor and use 1/4" backerboard...with the tile I will still have an incline. Do you have any suggestions for a smooth transition from tile to the hardwood?

Hi Cindy,
What you'll need is a transition strip where the bathroom and hallway flooring meet. As far as an getting them both to be the same height -- isn't going to happen.

Hello,
I am going to be installing flag stone at the front entrance of the inside of my house, a section that is about 6’ by 6’. The rest of the room has ¾” thick walnut flooring that I have installed about two months ago. I have planed to have a smooth transition between the stone and wood, and to achieve this I have installed the appropriate thickness of underlayment beneath the hardwood. My question to you is: can I but the stone directly against the hardwood, or do I need to leave a gap to allow for wood expansion and contraction? If a gap is require, what are my options?

Thank you
Gary

Hi Gary,
It should be ok to butt them up, and I say this based on the assumption that this area will be pretty much climate controlled and that the walnut flooring is nailed. Most people prefer to use a transition strip as it protects the edges where the two different flooring types meet. You're most likely going to have an issue with dirt/dust getting trapped where the two floors meet without a t-strip no matter how close you can get the two flooring types.

Hello, I'm thinking of putting irregular flagstone in an addittion. I used TJI's 14 7/8 1' on center and 3/4" MDF T&G for flooring. I'm going to have the stone cut between 1/2 to 3/4 of and inch. It's about 900sq. total. Would it be better to use a cement backer board like hardybacker or 30lb felt and wire mesh.

Thanks Matt

Hi Matt,
It sounds like you did a very good job on making a very stable base. It sounds like it would be strong enough that you can use hardybacker under it rather than having to use the felt/wire mesh.

I am going to lay a 900 sq ft. living room floor (new construction) of natural stone 3/4" to 1 1/2" thick stones. The base is a solid concrete slab. would you lay the stone directly on the slab, and what mortar mix is appropriate and how thick. I have done lots of rock laying but no flagstone before. Thanks, Wayne

Hi Wayne,
You'd want at least a medium set mortar for laying it. I would recommend using natural stone that is more uniform in thickness though.

Hello. I am planning to install natural stone on a 8'h x 7'w painted brick fireplace wall. What would be the process since the brick is painted?

~Mike

Hi Mike,
For best adhesion, I would recommend stripping the paint off of the brick.

Hi, this is going to sound awful, but have a section of flagstone floor that really is past its best, so wish to lift, use the better pieces elsewhere in the house, but concrete the section that is coming up and then tile. The existing base is just sand. Any ideas what I should do with this area with regards damp proofing this area? Any info appreciated Jackie

Hello,

I am remodelling a master bath and plan on installing, limestone natural tile. When remodelling I had to remove an old ceramic floor which was installed with a wire mesh and mortar. I do not wish to reinstall the mesh system but want to use a cementboard backer instead. My subfloor is in good condition and I have replaced sections where water damage was apparent.The sub floor is a minimum of 5/8" thick. Would using a cement board be sufficient?

In addition, I am installing a focus wall of natural stone which comes in precut sections and is approxiamatley 4cm thick (I am in Canada). What type of adhesive would you use to apply this wall? (the sections are fairly heavy).

Hi Jackie,

Where in the house is this flooring? Where do you live? Are you tired of the flagstone or would a good refinish bring it back to life?

You can read about various moisture-proofing approaches at: http://www.theflooringlady.com/moisture_proofing/

Hi Jerry,

I don't have experience with the wire mast and mortar, though I've seen it in older homes. I'd think the backerboard would be sufficient. That's what I have in my bathroom and it's holding well.

I don't have experience hanging stone on wall surfaces. It seems to be something's needed to strengthen the wall too.

hello, I'm building a house and the homeowner has specified crab orchard flagstone for the entire house inside and outside . The house is on a conventional floor system I'm not to worried about the inside of the house but very concerned about the balconies which are exposed to the elements I would like to use plywood for the subfloor but wonder how to accomplish the waterproofing of the subfloor.

Hi Freddy,

You do indeed need to put good weatherproofing down on the plywood. You could do a "blow down" asphalt-like layer before laying the flagstone on top, or you could use Bitchathane, or some other rubber membrane, as the layer between the plywood
and the flagstone.

It sounds lovely. I hope it works out for you.

Hello,

I am having a natural stone (Travertine) installed in the kitchen. Currently I have a "tile" look Linolium on the floor. Is it okay to lay the stone directly over the Linolium or should I have the Linolium removed first? The Linolium is directly on top of concrete. Will the Linolium hinder a proper adhesive seal if not removed or create a better water barrier if it remains and place the Travertine on top? FYI: The Travertine is a Tumble Travertine.

Thanks!

Ron,

You sure can lay it right over, IF you are positive the linoleum won't lift, that it has been properly glued down to the concrete without gaps or air bubbles. You would still have to use a thin-set for the new tile so the travertine will adhere properly.

I have made a Flagstone Porch that I have mortered. I'm now looking for either clear epoxy or polyurethane to pour over it. Birmingham stumped.

KC,

I would recommend the water-based Diamond Coat Varathane Polyurethane to apply over it.

We own a mid century home with an original application of flagstone slate for an entry way. We have a couple of flagstone tiles that are loose (each tile is probably about 16"x8" and mostly rectangular in shape). I plan on removing them for repair and reusing. What type of mortar should I use to reset as well as grout (and any other tricks I should know about)?

Thanks!

Greg

Greg,

Most home centers should have some type of motar repair adhesive you can use to reset a stone or two. If you do use new grout on those two stones, it may not match the rest of the area. Also, to protect the stones, you may need to reseal them.

Hi. I have a cabin that was built in 1860 and the floor is rock which we think was collected from around the property. It is laid tightly over a dirt/clay floor. I have been investigating ways to seal the floor and came across your website. I really don't want to pull all the rocks up in this process, it would be hours and hours of extra work. Is it possible for me to seal the floor with the Diamond Coat Varathane Polyurethane without having cement under the rock?
Thanks for any advice you can give.
Cynthia

Cynthia,

In virtually every type of stone flooring you will want to apply sealants over the top of the flooring.

But, I would check with the manufacturer to be sure that any moisture coming through the stone will not harm the sealant.

Hello Floooring Lady,
I am installing 3/4" flagstone in an entry way and 1" as floor protection for a woodstove. The stone will be set on a cement backerboard.

1. What is the minimum depth of mortar recommended?

2. Is the best means of application like tile in which the mortar is spread on the backerboard and a final pass is made with a notched trowel?

3. If a notched trowel is used, what size notch would be recommended?

4. Is the grout the same as what is used for tile?

5. Do you have any special techniques to get the best adhesion when setting the stone?

Thanks in advance,
Lonnie