Every hour a roof stays open during a Pacific Northwest storm means more water damage, and more of it is the kind you cannot see until mold shows up weeks later. A blue plastic sheet from the hardware store shreds in the next windstorm and often makes the leak worse. We install a real emergency roof tarp using 6-mil polyethylene material, secured from the ridge down past the eave so wind and rain cannot get underneath it. It holds until we can complete the permanent repair on a clear-weather window.
