WeatherWatch Mineral-Surfaced Leak Barrier is a key part of the GAF Lifetime Roofing System.1 It’s eligible for Lifetime limited warranty when used on Lifetime Shingle roofs1 and it’s an eligible component of GAF residential enhanced . How does WeatherWatch Protect your Roof? By Creating a barrier at the most vulnerable areas of your asphalt shingle (at the eaves and rakes, in valleys, & around chimneys, etc.), WeatherWatch  Mineral-Surfaced Leak Barrier helps prevent leaks due to water backing up in your gutters, wind-driven rain, and, in the North, damaging ice dams. It will also help protect your home from expensive wall and ceiling staining from leaks.