Where to use vapor retarders.Section R702.7 states that a vapor retarder is required on the interior side of all exterior wood-framed walls in climate zones 4 through 8, including marine 4. There are a few exceptions, however: Vapor retarders are not required on any below-grade or basement...
Vapor retarderWall cavityThe tight-envelope construction techniques to which architects and builders are now required to adhere have led to a steep reduction in air movement through walls. This means moisture gets trapped inside wall cavities without sufficient means for it to escape, leading to ...
vapor retarder 1.A membrane covering the outer surface of an insulated cold water pipe that is used to prevent moisture from penetrating the insulation and reaching the pipe. 2.A layer of material or laminate used to reduce, appreciably, the flow of water vapor into a roofing system. ...
A lot of people have heard advice aboutvapor barriers and vapor retarders. Many of them have walked away confused. A big part of the problem, I think, is that they’ve been told what to do—”Put it on the warm-in-winter side,” or “Never use one”—but they haven’t had...
for Impact Resistance of Plastic Film by the Free- Falling Dart Method 2.ASTM E96 Standard Test Methods for Water Vapor Transmission of Materials 3.ASTM E154 Standard Test Methods for Water Vapor Retarders Used in Contact with Earth Under Concrete Slabs, on Walls, or as Ground Cover ...
Polyethylene, a plastic sheet material, can be used as a vapor diffusion retarder for above-grade walls and ceilings (only) in very cold climates (in locations with 8,000 Heating Degree Days or higher). Most paint-like coatings also retard vapor diffusion. While it was once believed that ...
Depending on the perm level, a vapor barrier (or retarder) is a thick plastic sheet that can be installed to keep moisture and potentially dangerous chemicals out of your home by blocking them from entering through crawl spaces, roofs, walls, ceilings, and foundations. ...
Advanced Polyethylene vapor retarders that pass the ASTM E 1745 standard tests Kraft paper, often attached to one side of fiberglass batts (perm = 0.40). Vapor barrier paints (for the air-tight drywall system, for retrofits where finished walls and ceilings will not be replaced, or for ...
although it still has a ways to go on the topic of vapor retarders (see"Avoiding Wet Walls,"May/2017). The biggest change in the code is that air barriers are now required, and in most places in the U.S., the air barrier must be verified withblower door testing. In this article ...
to ceilings and walls. Perm ratings below 0.1 are often classified as impermeable, 0.1 to 1.0 are semi-impermeable, 1.0 to 10 are semi-permeable, and greater than 10 is considered permeable. “To take it a step further, when dealing with underslab vapor retarders and barriers, our industry...