Vapor retarder

Vapor retarder

Layer that inhibits vapor diffusion through a building envelope. Examples include polyethylene sheeting, foil facing, kraft paper facing on batt insulation, and low-permeability paints. Most building codes define a vapor retarder as 1 perm or less, with many common vapor retarders being significantly less than 1 perm.

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.
References in periodicals archive ?
Your reply was to put the vapor retarder directly on the concrete.
The components of this system include Wall Guardian FW-100A liquid-applied fibered acrylic air barrier which acts as a water/weather barrier and vapor retarder; GreatSeal LT-100 polyether Liquid Tape for board-to-board joints, windows, doors, masonry, roof flashings, etc.; and UT-40 Universal Tape for quickly sealing cracks, transitions, penetrations and seams in exterior wall systems.
** The code also states that you could apply a coating over the air impermeable insulation to create this Class II vapor retarder. Having pointed that out, I know of no practical coating that is relatively easy to apply that accomplishes this.
Later he joined the JM Roofing Division, where he received a patent for a fire-rated vapor retarder system and co-developed other patented products.
It is best to use unfaced fiberglass, and there is no need for a vapor retarder. The plywood that is likely to be the subfloor under the hardwood floor is an effective vapor retarder and all you need.
From the exterior to the interior, the studied wood-framed wall, shown in Figure 3, is comprised of cement based plaster, a layer of wall membrane, oriented strand board (OSB), cellulose fiber, a layer of vapor retarder and gypsum board.
One common insulation system is a layer of fiberglass insulation laminated to a water vapor retarder that is pulled across the top of the purlins (or outside of the girts)--conventionally referred to as "over-the-purlin" or "over-the-girt" (OP or OG) systems (also, "single layer" systems) within Standard 90.1-2007 (ASHRAE 2007).
We recommend filling the stud spaces with friction-fit fiberglass batts, covering the walls and ceiling with a 4-mil poly vapor retarder, and blowing insulation (cellulose insulation is a good choice) into the attic after the ceiling drywall is installed.
Special detailing of the panels minimized thermal bridging and supports a continuous vapor retarder. To preserve the vapor retarder while housing the building's heating, power and communications distribution systems, an interior utility chase is provided within the exterior walls.
The change allows unvented roof assemblies if two conditions are met: there's no vapor retarder between the attic and the home's living space, and the builder insulates between the rafters with air-impermeable insulation.
The analyses even returned one situation where the vapor barrier needed to be a vapor retarder (i.e., poly) located on the outside of the Oriental Strand Board (OSB) sheathing.
Bio-Based Systems' BioBase 501 soy-based foam insulation, Certain Teed's MemBrain vapor retarder, Taco's Hot Water D'Mand System, and Southern Diversified's American Pride interior latex paints are some of the most notable products named for the residential market.