Roof Pitch

Definition

Roof pitch is the steepness of a roof, expressed as the ratio of vertical rise to horizontal run. A 6/12 pitch means the roof rises 6 inches for every 12 inches of horizontal distance. Pitch can also be expressed in degrees or percentage. Most residential homes in the US use pitches between 4/12 and 8/12, with 6/12 being the most common. Pitch matters for estimating because steeper roofs have more actual surface area than their footprint — a 12/12 pitch has 41% more surface than its footprint. Pitch also affects material compatibility: low-slope roofs (under 2/12) require membrane roofing instead of shingles.