How Vapor Barriers Work

hi it's Steve Maxwell here and I'm going to talk to you about vapor retarders also called vapor barriers it's usually a kind of polyethylene plastic that's applied to the inside face the warm face of Stud frame walls to understand why a vapor retarder is necessary take a look at this cross-section of a wall that's the inside and outside surfaces with insulation between in this example the left side is the cold outside area as if it was winter and the inside is heated space if that warm air is allowed to make its way into the wall cavity as it will if the vapor barrier is not there droplets of condensation are going to form somewhere within that wall cavity and that's a bad thing because the moisture is going to trigger mold growth and pour into our air quality and that's bad that's why vapor retarders are applied to the warm side of a wall like this when it's in place that warm air cannot make its way into the wall cavity that wall cavity stays dry which is exactly what you want this is my favorite vapor retarder it's actually very smart in the way that it operates once again take a look at this wall cross-section with this product applied if there ever does happen to be high moisture buildup inside the wall it has the capacity to let that moisture dry it actually goes through this particular poly when the internal wall cavity humidity is low it acts as a conventional vapor barrier to stop more moisture moving in the product is called membrane spelled kind of differently that's the latest and best on the market right now

Channel: Bailey Line Road

Views: 296,631

Keywords: vapor barrier, home insulation, vapor barrier installation, air barrier, wall insulation, vapour barrier, crawl space, how to install vapor barrier, basement vapor barrier, vapor barrier ceiling, vapour barrier installation, crawl space foundation, vapour barrier basement, 6 mil poly vapour barrier, crawl space heater, crawl space vents, crawl space door, crawl space insulation, moisture barrier, homesteading, steve maxwell, bailey line road, diy projects, do it yourself

Id: fSdD9r5K4RU

Length: 1min 31sec (91 seconds)

Published: Sat Jan 16 2016