Vapor retarders / Guides

Vapor retarder latex primer instead of polyethylene sheet
Air and vapour barriers

Replacing polyethylene vapour barriers with latex paint vapor control

...vapor semi-permeable interior finishes. The following main principles are recommended: Avoid vapor barriers where vapor retarders will work, avoid vapor retarders where vapor permeable materials will work. Avoid the installation of a vapor barrier on both sides of the wall assembly. Avoid using poly, foil fac...

Tyvek home wrap left exposed to wind and UV rays
Air and vapour barriers

Choosing the right house wrap / weather barrier, which is best?

...retarders. The higher the perm rating or Ng, the quicker moisture can evaporate. *Ng stands for Nanograms, or billionths of a gram of water. That 60 Ng number refers to the amount of water that will pass through a square meter of a material in a second [ 60 ng /( Pa.s.m2 )]. 1 U.S. perm is actually 57 Ng, that 3 bi...

Poly vapour barriers in air conditioned houses can cause mold and rot
Healthy indoor air quality

Why you should Never Install Air-Con in a Home with a Vapor Barrier

...Vapor Barrier + Air-Con = Damp Moldy Walls So here's a little known fact that most HVAC installers won't tell a potential new client for central air; Polyethylene vapor barriers in combination with air conditioning in homes can rot walls because of the condensation they may cause. This is why if you have a newer home...

Finished basements can lead to mold and mildew
Healthy indoor air quality

Why are basements moldy? How to fix or Prevent a Moldy Basement

...Vapor barriers on basement insulation will rot your walls " We put vapour barriers in basement wall assemblies to keep moisture from getting into them, as if they didn't already contain thousands of litres of water. Polyethylene won't keep foundations dry, they are already soaking wet. All it will do is prevent the t...