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 is eligible for a Lifetime limited warranty when used on Lifetime Shingle roofs,2 and it's an eligible component of GAF residential enhanced warranties. It is also covered by a 10-year limited warranty3 when used with other approved non-asphaltic roof coverings.