TIPS FOR CHOOSING HOUSEWRAP

摘要

When water gets behind exterior cladding-as it inevitably will-it should always encounter a weather-resistive barrier to protect the structure from moisture damage. For many new homes, housewrap serves as this last line of defense. It's crucial, then, to fully understand the performance differences between housewraps and to use the right one for the job ... or suffer expensive consequences. Most synthetic housewraps are made from polyolefin, a common class of plastic, but in two fundamentally different ways: A woven variety uses long threads running the length and width of the wrap, resembling cheesecloth; a nonwoven type uses shorter fibers set in a random pattern, much like OSB panels. Of the two types, nonwoven wraps do a superior job reducing the chance of moisture problems, and the extra $200 or so cost premium for the average house is cheap insurance against callbacks and more serious issues. Woven wraps tend to rip or tear more readily than nonwoven wraps, like a run in a nylon stocking, a snag in woven house-wrap can quickly grow, especially when exposed to wind. This tendency is especially critical when wraps are installed by hurried laborers and remain exposed to the elements for weeks.