Many homes have sloping roof lines that intersect taller sidewalls. If rain penetrates the siding on this house, it could easily find a path behind the lower sheet of house wrap.
Especially, how some upper pieces were installed first then overlapped by pieces installed later at a lower point in the wall. What did concern me was how little scraps of house wrap were cobbled together. No real problem here, but the lack of consistency caught my eye. Another builder I met with, used a combination of Tyvek (R) and Typar (R) on the same house. Poorly installed housewrap is just as bad as no housewrap. The sidewall had icicles protruding from beneath one section of the vinyl siding where rain had penetrated the siding and was frozen in its tracks trying to escape. But vinyl siding is not waterproof, as I learned while inspecting a house in frigid temperatures after a heavy, wind-driven rain. Many builders are convinced that nothing gets past vinyl siding. This seems especially true when houses are sided with vinyl. Too often, builders neglect to wrap their houses with some type of water resistant membrane before they apply siding. The details provided will improve your chances of preventing leakage, even in high exposure conditions. I have investigated structural failures and repaired homes for many years. A second line of protection should be provided in all homes, especially those exposed to wind-driven rain. Moderate and severe weather can drive water through the smallest of cracks in any siding. Lesson learned: properly-installed siding isn’t water proof! The water ran down the face of the felt paper, behind the window flashing and head casing. Heavy east winds pressurized the wall and guided rain water through the butt joints of the siding above the window. I had attached the window flashing against the felt paper rather than tucking it under the paper. Later, as habit dictated, I installed the window z-flashing above the window head casing and sided the wall. Then the obvious hit me.ĭuring construction, this window was back-ordered, so I had decided to pre-wrap the entire wall with 15# felt and pop in the unit when it arrived. Finally, out of desperation, I removed every course of bevel siding from the east wall. During this 3-year period, I sprayed water, applied caulk and tightened every joint and flashed connection on the east wall of the home – with no luck. Each time there was a heavy east wind driving the rain directly against the window and wall surrounding it. This leak occurred once a year for 3 consecutive years. Well, fixing leaks can be a tricky proposition. A late-night phone call explained in detail how many drips-per-minute were falling from the head jamb of the east-facing double-mullion window. But 6 months after they moved in, a wind-driven rain converted my plum into a prune. The clients were overjoyed with the finished product and moved in ahead of the scheduled closing date. It was an expensive home I had contracted during the early days of my career: A large Gambrel on the peak of the highest hill in town. I vividly remember the job where I learned that even properly installed siding isn’t waterproof. Some information contained in it may be outdated.Ĭareful detailing of house wrap and flashing connections will reduce maintenance and lengthen the working life of structural components in wood-frame structures. Please note: This older article by our former faculty member remains available on our site for archival purposes.