Here’s how to select the best high-performance building wrap.
The best housewrap manages water and air infiltration within exterior wall systems. Choose a product that is tear-resistant and designed to withstand heavy winds and jobsite rigors. The product should also offer superior surfactant resistance to minimize water penetration and should incorporate UV inhibitors into its coating and fibers.
The above represents the basics for choosing the right product, but as with everything, there are nuances. The following 5 FAQs are good guidance for the proper installation of wraps, also known as weather-resistant barriers (WRBs).
1. Is Housewrap Durable?
It’s an obvious question, but an important one. A durable WRB is one that stays in place, has exceptional tear strength, and can stand up to surfactants and UV rays.
Opt for a high-performance material that has exceptional tear resistance and is designed to withstand heavy winds and jobsite rigors. Additionally, housewraWRBs with superior surfactant resistance will minimize water penetration and the resulting component degradation.
Finally, it is best to work with a high-performance material that incorporates UV inhibitors into its coating and fibers. This prevents deterioration that can occur from UV exposure
2. Does Building Wrap Breathe?
A building wrap must breathe to prevent moisture vapor from getting trapped in the wall cavity. Use high-tech products that can balance water holdout with an optimal perm rating of 10 to 20 perms. If you stay in this perm rating range, you will keep water from entering the wall cavity while allowing moisture vapor to escape.
3. Can Housewrap Serve as an Air Barrier?
It should. It is not too lofty a goal to expect a WRBs to perform as an air barrier that helps reduce air infiltration. High-performance products are effective air barriers because they reduce convective wind washing against sheathings and air infiltration into stud wall cavities.
When installed as part of an air barrier assembly, a WRB can reduce drafts in homes, increase indoor air quality and decrease energy use. It does this by reducing the amount of non-conditioned air that enters and exits conditioned wall cavities.
4. Does Housewrap Include a System Warranty?
A good warranty speaks volumes about the quality of a product. Some high-performance options on the market back builders with excellent warranties on labor and materials.
5. Is Housewrap Part of a Holistic System?
These products don't operate in a vacuum. They are part of a holistic approach to airtight construction, or at least that they should be. As such, they require thorough, comprehensive integration with other elements of the building envelope in order to retain system integrity.
In other words, be sure the WRB includes compatible tapes for seaming and adhesive flashings for openings. These details vastly improve the air and moisture resistance of the product.
Matt Power is an expert on building science. He has covered construction practices for nearly 30 years, winning dozens of awards for editorial excellence. As Green Builder’s Editor-in-Chief for nearly 10 years, Power continues to urge builders and homeowners to new levels of performance and innovation.