Raven Industries Vapor Barrier

January 4, 2008
raven industries vapor barrier
Raven Industries manufactures a wide variety of products, but their Rufco water vapor barrier is an important development in the home construction and remodelling arena. Black plastic isn’t necessarily a vapor barrier. You need to buy plastic that’s designed as a vapor barrier, and tested for its effectiveness. If you want to install flooring in your basement, a vapor barrier is important to the life of the new floor. Moisture wicks through concrete or wood into your home or office, and that moisture is wicked into the flooring, especially wood and carpet. That moisture can be damaging, so stop it before it comes inside with a quality vapor barrier.

A water vapor barrier is an essential ingredient of new home construction. A water vapor barrier — actually, water vapor retarder — is any material that resists passage of water vapor through walls, floors, ceilings, and other building assemblies. Some materials, such as drywall, are not very good water vapor barriers. They must be further protected by high-performance water vapor barriers such as Raven Industries’ Rufco product line.

Rufco is a high density polyethylene plastic sheet. It is formed of two laminated layers of plastic, laid with their grains across each other for tear-resistance. This cross-laminated design provides excellent tear and puncture resistance and limited stretching.

Raven Industries, based in Sioux Falls, South Dakota, is a manufacturer of plastic films of many kinds. The company’s engineered products division fabricates polyethylene and polypropylene films in very low, low, medium, and high density formulas and in thicknesses ranging from ultra-thin 0.25 mil to 40 mils. These films are used in applications ranging from shrink-wrap packaging to lining ponds, and of course in home construction water vapor barriers.

A water vapor barrier must be continuous in order to block water vapor seepage effectively. For a house, that means a very large continuous sheet of water vapor barrier material is needed. Rufco comes in stock rolls of 100 feet long by 4 to 60 feet wide, which can be fused together using the company’s specially formulated “seaming” tape. Rufco can also be ordered in custom larger widths to reduce on-site seaming labor.

This vapor barrier can be used directly on the ground, as in a crawl space, keeping the air above dryer than it would otherwise be. It can be applied to concrete walls, on the under side of floor joists, and even as a house wrap. When applying this product in a crawl space, you want to create a continuous cover from ground level, down the foundation walls, across the debris-free ground, and up the foundation walls. Raven provides great directions to help you create a vapor-resistant barrier.

No water vapor barrier is perfect; it will let water pass, however slowly. The performance of a water vapor barrier is measured by its Water Vapor Transmission Rate (WVTR). Rufco water vapor barrier films have a low WVTR of 0.02 gms/100 sq. ins./day, using the testing method specified in ASTM E96. This means that only 0.02 grams of water pass through every 100 square inches of Rufco film in a whole day, at normal temperatures and relative humidity. These WVTR results translate into a US Perms (permeability) rating of 0.045.

Rufco film is also a good gas barrier. Its oxygen permeability rating is only 45 to 85 cc/100 square inches/day at 77 degrees Fahrenheit, using the testing method specified in ASTM D1434. Rufco film blocks over 97 percent of radon gas.

Rufco comes in four styles to meet varying needs and budgets. Rufco 300 is a 3 mils thickness. It is best suited for above-ground applications such as silage covers, temporary walls, wood products covers, etc. Rufco 400 and 400SSB (Super Sampson Barrier) are slightly thicket at 3.5 mils. Both are certified to meet ASTM E-1745, Class C, as an underslab vapor retarder.

As vapor barriers go, Rufco products by Raven Industries are a quality family. Their engineering properties make them reliable, effective vapor barriers for many applications ranging from home insulation to ice skating rink liners, and even poultry house roofs. The Rufco line of water vapor barrier films has proven itself in a variety of construction projects for many years.

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