weather-barriers / Green Building & Sustainable Home Renovation Information & Advice

A technical guide to understanding the role weather barriers and rainscreens play in a wall, choosing the right products and installation tips for optimum performance. They're officially known as water-resistive barriers or WRBs, sometimes weather-resistive barriers, but in practical terms they are more commonly called...

There has been a steady evolution in the way we build homes over the last couple of decades, and the old standby wall recipe of 2x6s, fiberglass insulation and polyethylene doesn't measure up anymore with building codes, nor the trend towards high performance housing. One aspect of wall assemblies that is garnering som...

Vapor Barriers in walls, why polyethylene can be problematic It would probably surprise many home builders to hear what really causes moisture accumulation in walls, and what to do to prevent it. An understanding of how water vapor moves through walls is important, so a good place to start would be with our page explai...

The difference between 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 effect...

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 w...

Heat pump electric hot water heaters, good or bad idea? Water heaters are generally the biggest energy drain in a home after heating. so Air-to-water heat pump water heaters are potentially a big energy saver, particularly when the main heat source in a home is an air source heat pump, as the water heater can in effect...

We found this video at Whole Systems Design, a New England based company who identify, design, and develop human habitats. In their own words from their website : "We design and implement regenerative food, fuel, and shelter systems that operate on current solar energy. These are homesteads, farms and schools fit for a...

Approximately 100 times more water vapor is carried into our walls by 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 ...

There are many manufacturers of heat pump water heaters on the market, which, rather than heating water with an electric coil as a normal electric hot water tank does, employ an evaporator to extract heat from the air (either interior or exterior) and use it to make hot water. The byproduct of an air-to-water heat pump...

It might seem like pie in the sky, but with these easy to read DIY instructions from the good folks at the Endeavour Centre your dream of a warm, net-zero shower is well within reach.  This tutorial will show you how to make excellent use of an easy to put together, handmade, solar hot water system. Use it to build the...

The Ecohome Demo House has a vapor permeable exterior air barrier, and with an ACH rate of .69 it is  several times more airtight than the average new home. Air leakage can be responsible for up to 1/3 of the total heat loss of a home and cause significant moisture damage in walls, as one small hole can be responsible ...