Consider a 3-year-old, 3-story apartment building in Seattle clad with vinyl lap siding. Inspection has confirmed that the vinyl siding system was installed in conformance with the manufacturer’s installation instructions and with industry standards published by the Vinyl Siding Institute (www.vinylsiding.org). Even so, the oriented strandboard (OSB) sheathing behind this siding was found to be extraordinarily water-damaged and decayed.
