Photo courtesy Inspec. Photo © Matt Bryan
When three separate wood-frame structures in the northern United States showed evidence of possible moisture infiltration in the roof areas, an independent architectural/engineering consulting firm was called in to confirm the issue was present, determine the amount of damage, find the source, and design solutions. All three buildings had been built within the last 10 years, and shared similar design characteristics, with commercial space on the first floor and apartments on the upper levels. When all three assessments had uncovered premature failures to some structural components of the roof assemblies as a result of accumulated moisture in the truss space, a thorough investigation into the source had to be conducted.
The investigations found many bypasses in the vapor retarder that allowed warm, moist interior air to migrate into the truss space. The party walls between apartment units, which were a double-stud wall construction, interrupted the continuity of the vapor retarder.
An article in our newest, sponsored e-book, Sealing the Building Envelope, discusses the steps taken to remedy the problem of moisture infiltration in the three buildings. To get your copy of this free, downloadable resource in either pdf or digital edition, visit www.constructionspecifier.com/ebook/georgia-pacific-sealing-the-building-envelope-e-book.
