Flashing Material Calculator

How It Works

Flashing is the unsung hero of a waterproof roof — over 90% of roof leaks originate at flashing points, not in the field shingles. Drip edge goes along all eaves and rakes to direct water into gutters. Valley flashing (W-metal or woven shingles) handles the heavy water flow where two roof planes meet. Step flashing consists of small L-shaped pieces woven between shingles where the roof meets a wall. Chimney flashing uses a two-part system: step flashing on the sides and a cricket/saddle on the uphill side. Pipe boots are rubber-gasketed cones that seal around plumbing vents. Replace all flashing during a re-roof — old flashing is the #1 cause of post-replacement leaks.