a material that severely limits the movement of water vapor (water in a gaseous state) from one side of the material to the other. The relationship of this term to the term vapor retarder is complex and often indeterminate. Read a complete discussion and delineation of water and air, barriers and retarders, Understanding the Terms Barrier and Retarder for Vapor and Air by Joe Lstiburek's on the Building Science website.
A moisture-impervious layer applied to the warm side for the purpose of preventing moisture travel.
Layer which prevents the passage of water into a material or structure.
A moisture-impervious layer applied to the surfaces enclosing a humid space to prevent moisture travel to a point where it may condense due to lower temperature.
a clothing item which is impervious to water thereby serving as a barrier to the transportation of water vapor
a good way to prevent moisture from wicking through the floor," he notes
a layer of material that slows or prevents the absorption or release of moisture from or into a wall or floor
a material that offers a higher resistance to the diffusion of water vapor than most other materials
a material that stops the flow of moisture
a material used to prevent the transfer of water vapor from one area to another
a must, all the way around -- on the warm side
an impermeable material (such as heavy plastic) installed on the warm side of the framing under the plaster or wall board
an impermeable material, typically plastic or asphalt paper, attached to insulation
an item designed to trap body heat and hold in body moisture
a plastic sheeting that prevents air and moisture infiltration into the building and can improve its energy efficiency
a specially treated plastic sheet that prevents condensation of water vapors, which are a natural occurrence from the earth, from entering the crawl space
a moisture-proof layer of material used to reduce moisture migration
A layer of material through which water vapor will not pass.
A material which retards the transmission of water vapor. It is rated in perms ("permeance"). The smaller the perm rating, the better the water vapor resistance. A good vapor barrier should have a perm rating no greater than 1.0.
A waterproof material that is used to prevent moisture from migrating from damp to dry areas, where it may condense and cause problems.
A waterproof membrane in a floor, wall, or ceiling that blocks the transfer of condensation.
A waterproof material or film placed between a heated area of the home and an area that is not heated to prevent moisture from seeping between the two areas.
a material designed to resist the migration of moisture through a wall or other building component. As water vapor in the air moves from a warmer to a cooler part of the building it can settle and condense on cooler building components, such as rafters, beams and walls, eventually causing those components to mildew, rust or rot. Vapor barriers, which are impermeable to water vapor migration, help to protect against this possibility. The most common vapor barriers are made of plastic, but other materials, including oil paint, can also serve the purpose.
Paper or plastic material used to keep moisture from moving through a wall.
A building product installed on exterior walls and ceilings under the drywall and on the warm side of the insulation. It is used to retard the movement of water vapor into walls and prevent condensation within them. Normally, polyethylene plastic sheeting is used.
Any material used to prevent the passage of water vapor.
Watertight material used to prevent the passage of moisture or water vapor into and through walls and under concrete slabs.
A black plastic material placed under the concrete of a foundation to resist moisture.
The material used to prevent moisture from penetrating walls or floors.
A material which prevents or impedes the passage of water vapor through the walls of a structure or container. Aluminum is an excellent vapor barrier.
Also called a vapor retarder, this is a material that retards the movement of water vapor through a building element (such as walls, floors, and ceilings) and prevents metals from corroding and insulation and structural wood from becoming damp.
Material used to prevent passage of vapor or moisture from one area to another. Kraft paper or foil is used on roll-type (batt) insulation, foil used on insulation board. Sometimes a plastic membrane is installed over insulation without a vapor barrier before the inside walls are covered.
A watertight material used to prevent the passage of moisture into or through floors, walls and ceilings.
A material such as plastic that prevents the passage of moisture.
A water-resistant material as used to prevent the passage of moisture and vapors.
A membrane which is placed between the insulation and the roof deck to retard water vapor in the building from entering the insulation and condensing into liquid water.
A barrier designed to restrict passage of water vapor through a wall or roof. In the roofing industry, barrier material should be rated at 0.2 perm or less. A covering of metal foil or plastic that inhibits the transmission of moisture or vapor through it; used in conjunction with building insulation. See also Permeance.
Waterproof membrane placed under concrete floor slabs that are placed on a grade.
A vapor barrier is a Class I vapor retarder. Vapor barriers are materials that are vapor impermeable.
Visquene installed to prevent moisture from passing between two locations. A vapor barrier is installed on top of the foundation fill prior to pouring the slab. This prevents condensation entering the floor of the home from the ground below.
Treated paper or plastic film that retards the flow of air and moisture.
insulating materials used to prevent the buildup of moisture, whether by condensation or penetration in walls, floors and other parts of a building
(1) A sheet material designed to restrict the passage of water vapor through a roof or wall. In the roofing industry, a vapor retarder should have a perm rating of 0.5 or less; (2) Roof component designed to obstruct water vapor flow through a roof or wall. See VAPOR RETARDER.
A material with a permeance of one perm or less which provides resistance to the transmission of water vapor.
A material, such as foil, plastic film or specially coated paper, with a high resistance to vapor movement,used to control condensation or prevent migration of moisture.
is material such as paper, metal or paint used to prevent vapor from passing from rooms into the outside walls.
A continuous plastic membrane which surrounds the entire thermal envelope of a house and prevents moisture penetration into the wall cavity. Also referred to as a Vapor Retarder.
A plastic film or other product used on exterior walls to prevent the formation of vapor behind the adjoining interior walls. A properly installed vapor barrier can prevent the formation of mildew due to water vapor between the wall and the wallpaper.
A material with a high resistance to vapor movement, such as foil, plastic films or specially coated paper, that is used to control condensation or prevent migration of moisture.
Material used to retard the flow of vapor or moisture into walls and thus prevent condensation within them.
Material placed to prevent vapor or moisture from passing through a wall, floor or partition. Materials include paper, metal, plastic and paint..
MATERIAL SUCH AS COATED PAPER, METAL, PLASTIC, OR PAINT WHICH IS USED TO PREVENT VAPOR FROM PASSING FROM ROOMS INTO OUTSIDE WALL CAVITIES, ATTICS, OR CRAWL SPACES.
A material that prevents the passage of water or water vapor through it.
A moisture-impervious material, such as plastic sheeting, placed on the subbase under a concrete slab to help prevent moisture vapor transmission.
The element in a wall, floor or ceiling that does not allow moisture or air to penetrate and is used to prevent condensation in insulation.
Material used to retard the flow of vapor or moisture to prevent condensation from forming on a surface.
Material used to retard the movement of water vapor into walls and prevent condensation in them. Usually considered as having a perm value of less than 1.0. Applied separately over the warm side of exposed walls or as part of batt or blanket insulation.
section of material that resists passage of water vapor.
A material, usually in thin sheet form or combined with a sheathing material, designed to prevent the passage of moisture through a wall or floor with the aim or preventing condensation within the wall.
Generally, vapor barrier is a term often used when discussing humidity (or vapor pressure) where vapor (e.g. water vapor) is prevented from moving between discrete spaces or volumes. Because no material or installation is perfect, moisture will still cross the surface to be protected; the formal term is therefore vapor retarder. Similarly, air barriers are intended to eliminate air infiltration, but are more accurately entitled air retarders.