Video: How Important Is Your WRB? | Continuous Insulation with Foam Sheathing

by Timothy Ahrenholz

Published on January 16, 2019.

As you design a building envelope, it can be easy to focus on getting the insulation right. After all, the International Building Code goes to great lengths to require specific R-values and U-factors. And while the thermal control layer is certainly important, the building code is less specific about the other major control layers: the water resistive barrier (WRB), the air barrier, and the vapor control layer. Water, air, and vapor are harder to quantify than heat, which is why the code spends less time discussing them. But if your wall fails to control them, all the insulation in the world won’t help.

Fortunately, the folks at continousinsulation.org have compiled many helpful, free resources to give you guidance where the code is silent. Visit the application pages on WRBs, air barriers, water vapor control, and thermal insulation for articles, research reports, step-by-step installation guides, and more.

Also, take a look at this quick video, part of a series where Joe Lstiburek, Ph.D., P.Eng, explores effective building envelope design:

For additional information, review the following articles, as well as the previous videos in this series:

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