air barrier / Guides

Interior sheathing as air & vapor barriers in wood frame construction
Air and vapour barriers

Interior sheathing as an air and vapour or vapor barrier

...air barrier and vapour barrier, and eliminating the need to install a separate product to do that job. One of the benefits of OSB as an air barrier is that it is solid. A polyethylene or foil air barrier can be easily pierced by the slightest touch with a sharp tool, without even realizing it. In contrast, it is unli...

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

...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 with ...

Exterior air barrier membrane © Ecohome
Air and vapour barriers

How to install an air barrier for reduced air leakage

...barrier is to prevent vapour diffusion and the job of an air barrier is to stop air leakage through differences in air pressure between inside and out. A wall system should have one vapour barrier, but can have many air barriers. A vapour barrier can act as a very effective air barrier, but an air barrier does not (and...

Air barriers are essential to a properly functioning wall system
Air and vapour barriers

What is an air barrier?

...air leakage than is carried by vapor diffusion. That makes air barriers 100 times more important than vapour barriers, so why is no one talking about them? We don't talk about air barriers because we are too busy talking about vapor barriers. An air barrier is not something you walk into a building supply store and b...

Air and vapour barriers

Aerobarrier home and attic air-sealing spray

...air barrier that you can’t possibly see - from as small as a human hair to as big as a half-inch wide. The airflow in the home is monitored in real time by the blower door computer. Depending on the building size, the number of leaks and the client’s desired level of airtightness, the process of installing Aerobarrie...

The difference between air barriers and vapour barriers
Air and vapour barriers

The Difference between air barriers and vapor barriers

...air barriers and vapor barriers The job of a vapor barrier is to prevent vapor diffusion, and the job of an air barrier is to stop air leakage through differences in air pressure. A wall system should have one vapor barrier, but can have many air barriers. A vapor barrier can act as a very effective air barrier, but ...

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

Replacing polyethylene vapour barriers with latex paint vapor control

...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 effectively as an air barrier if it is ca...

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

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

...barriers are often intended to act as an air barrier as well, but the most common installation techniques (staples, nails and hastily installed tape) mean it is a rare case when they actually do a good job at air sealing. Manufacturers will rightly claim their products are a suitable choice for an air barrier, and they...

Passive House wall system ; Larsen Trusses & dense-packed cellulose insulation
Wall assemblies - new construction

Larsen truss wall systems with double-stud construction & extra insulation for new homes & energy efficient home renovation

...barrier and air barrier 11 7/8" TGIs (I-joists) as a double-stud wall attached to the exterior of the sheathing (R42) 1.5" ECO4 Wood fiber-board rigid exterior insulation (R4) Weather barrier (WRB) Strapping Exterior cladding * Both homes are built on a raft-slab ‘ slab on grade ICF Forming kit ’ with 12 ...

Insulating crawlspaces as part of home renovation
Crawl spaces

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

...air barrier, but EPS and mineral wool are not. Air doesn’t leak through intact concrete but it is quite likely that crawlspace walls will leak air. If you have a stone foundation, old cracked concrete or cinderblocks, bringing the poly barrier up the wall and sealing it to the rim joists will provide you with an air ba...

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?

...air baffles ensure soffit ventilation works properly © InterNACHI Some builders have expressed concerned that ridge vents aren't sufficient because they can be blocked by snow, but snow isn't an air barrier. It will slow the air, but as long as the vent runs the length of the roof there should be enough air flowing...