Poly vapour barriers / Guides

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

Replacing polyethylene vapour barriers with latex paint vapor control

...poly that gets installed as a vapour barrier is mistaken for, and almost entirely relied upon to act as the air barrier. The purpose of the two barriers should not be confused - the job of the vapour barrier is to control vapour diffusion, the job of the air barrier is to control air leakage. 6 mil poly can work effe...

Radon and vapour barrier below slab on grade floor
Radon in Homes - Mitigation

Vapour / radon barriers below slab floors

...polyethylene as a sub-slab vapour barrier, we used a 10 mil barrier and a radon evacuation stack to lower radon gas levels in homes, research shows (see below) that thicker membranes offer more effective protection. In this video we are installing a 10 mil vapour barrier but we would probably use a thick vapor barrie...

Insulating crawlspaces as part of home renovation
Crawl spaces

How to insulate crawlspaces properly as part of renovating an older home

...vapour barrier © Pescrawlspaces.com For those with nothing but a dirt floor, the single most important thing to do will not cost much - cut off the moisture supply to the air by laying down polyethylene directly on the ground. The standard 6 mil poly vapour barrier will work fine as a DIY solution. Do the best job ...

What is Interstitial Condensation? (And how to stop it!)
Walls and Roofs

What is Interstitial Condensation in Walls or Roofs? (And how to stop it!)

...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 with an impermeable poly vapor barrier, you are at risk of drawing warm and humid exterior air into your wall assembly where it can condense on that ...

How to insulate basements properly
Insulation and soundproofing

Best practices for basement insulation in new home construction

...vapour retarder primer ) is recomended as an interior vapour control layer below grade. It is most important to not include a polyethylene vapour barrier or other vapour impermeable materials that prevent walls from drying. 6 mil poly vapour barriers are an above grade solution intended to allow walls to dry to the e...

Step by step guide for slab-on-grade home construction
Slab on Grade

Slab-on-grade construction: the ecoHOME A to Z Slab building guide

...VAPOUR BARRIERS FOR SLAB ON GRADE: Install anchor bolts and lateral insulating panels and then the center panels. Next, cut around the plumbing system and mechanical equipment. Ensure that there are no gaps in the insulation, even in problem areas. Install a polyethylene air / vapour barrier over the entire ins...

Frost in Attics: What causes Attic Ice? How to Fix it?
Roof assemblies - renovation

Why is there frost in my attic? Is ice in roofs a problem & How do I stop it?

...polyethylene vapour barrier over the whole surface (it can go up and down over joists) then reinstalling the insulation. Make sure the poly is well-taped at the seams and on the sides as well, it will serve little purpose if it allows air to flow up at the exterior edges. Pay close attention to not tear it while you're...

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

...polyethylene vapor barriers in wall assemblies in all but the coldest of climates, or at least change their location within the wall assembly to avoid the possibility of interstitial condensation damaging wall structures . Moisture-impenetrable vapor barriers work great in winter and, before air conditioning and heav...

Blower Door Tests - What's the Cost & Who Does Them?
Air and vapour barriers

What is a blower door test? What's the cost? How do you find a company to do one?

...barriers in the form of 6 mil poly vapor barriers , exterior weather resistant barriers (WRBs) , tapes and caulking etc, so the cost doesn’t really go up much. All you need to do to improve the air seal is take your time and be a bit more careful, and what’s the point of taping the joints of a membrane if you don’t do ...