When I first started to look into these products, I was using the acronym WRB to stand for “weather-resistive barrier.” It seems that “weather-resistive barrier” and “water-resistive barrier” are often used interchangeably, both by building professionals and manufacturers. However, I learned enough in my interviews with trusted building professionals to change the acronym so that “WRB” stood, more specifically, for “water-resistive barrier.”
The thing is, it’s important to be very specific about the four different control layers in a building assembly—water, air, vapor, and thermal. Unlike the water-resistive barrier, which may terminate at the top of the wall beneath a roof overhang, for example, an air barrier is a continuous assembly that must connect from one plane of a building to the next. As you’ll see, the products often can do more than just keep water out of your walls and you may be able to use a water-resistive barrier as the air barrier on walls, but that is only one dimension of the air-control assembly.
As you choose products for your work, take the advice of the building professional I spoke with and think about the four control layers individually at first. Then, if you can use a product that does double duty, great. Here are nine products that all work first-and-foremost as water-resistive barriers. Some have been around the block, others you may not have encountered yet.
DuPont Tyvek Homewrap (photo above)
For a while it seemed that the brand name “Tyvek” was used synonymously with “housewrap.” This is because it was the first synthetic product to hit the American market, long before a WRB was required by the International Residential Code (IRC). Tyvek HomeWrap is nonwoven, nonperforated, high-density polyethylene. It has a perm rating of 56, one of the highest available, and is UV…