Pitch

Pitch is defined as the steepness or angle of a roof, expressed as a ratio of vertical rise to horizontal run. A roof with a 6:12 pitch rises 6 inches for every 12 inches of horizontal distance. Most asphalt shingle manufacturers require a minimum pitch of 4:12 (18.4 degrees) for standard installation. Steeper pitches increase material quantity, labor difficulty, and safety requirements, with roofs at 8:12 (33.7 degrees) or greater typically classified as steep-slope and requiring specialized equipment.