How to use
Estimate roof surface, squares, shingle bundles, felt rolls and cost.
Limits
With footprint alone, the overhang estimate uses A + 4.4e(√A + e), where e is horizontal overhang. With measured rectangular sides, use (l + 2e)(w + 2e). Apply the slope factor to that horizontal area. One roofing square is 100 ft². Counts use typical US coverage; check product specifications.