By creating a barrier at the most vulnerable areas of your asphalt shingle or metal roof (at the eaves and rakes, in valleys, around chimneys, etc.), StormGuard® Film-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. StormGuard® Film-Surfaced Leak Barrier is a key part of the GAF Lifetime Roofing System.2 It’s eligible for Lifetime ltd. warranty when used on Lifetime Shingle roofs2 and it’s an eligible component of GAF residential enhanced warranties. It’s also covered by up to a 10-year ltd. warranty3 when used with other approved non-asphaltic roof coverings.