When it comes to call-backs about leaks, contractors are generally most worried about potential product defects. Instead, they should be much more concerned about installation issues, as forensic analysis finds that improper installation practices are the leading cause of leaks. According to water intrusion expert Gene Summy, contractors can avoid “80-90% of litigation out there” by using the correct installation methods. Here then, are some of the most common installation errors we see that lead to call-backs:
Improper application of WRB
Properly shingled housewrap is key to keeping the water out, but we often see WRBs installed with reverse laps. Instead of forming a continuous plane down the wall, reverse laps create a gap that allows water to flow under the WRB and onto the wall. To avoid this outcome, make sure that you always install WRBs from the bottom first, with each successive course lapping on top of the lower course.
Not using sealants
AAMA window installation best practices specify the use of a sealant with self-adhesive flashings, but we still see failures from installers that don’t heed this advice. Sealant can fill small voids in OSB and other substrates, and improve the flashing’s bond to the surface, both of which will greatly reduce the risk of leaks.
Mixing and matching products
Adhesives and sealants from different manufacturers can have different chemical properties that are incompatible for use together. Sometimes this incompatibility can cause chemical reactions that lead to catastrophic product failure. If you mix and match products from different manufacturers, it’s imperative to test their compatibility before installation.
Not following manufacturer guidelines
Many self-adhesive products have installation temperature guidelines and for good reason. We see the poor adhesion that results from installing flashing in temperatures both below and above the guidelines. The lesson? Read the manufacturer’s installation temperature guidelines and follow them.
A cautionary example
Henry recently helped remediate serious moisture-intrusion issues at a townhome complex in rainy Portland, Oregon. In this case, the original builder chose poor weatherization products and used improper installation practices. After remediating the rot and to keep the repaired building dry for years to come, the contractor used the Henry 1-2-3 Moisture Control System that's backed by an industry-leading 15-year warranty. Read the full project profile here. Read the full project profile here.
Contact a Henry weatherization expert for advice and support on your next job.
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