Vapor retarder. vapor-tight said of a surface that is enclosed so as to resist the passage of vapor, often including the use of a gasket around its periphery.
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
A moisture-resistant layer applied to the surfaces of humid spaces that prevents moisture from traveling to a point where it can condense due to lower temperat
