Slope

Slope is defined as the incline of a roof surface, expressed as inches of rise per foot of horizontal run. Slope and pitch are often used interchangeably in residential roofing, though technically pitch refers to the ratio of rise to the full span. The Asphalt Roofing Manufacturers Association (ARMA) classifies roofs as low-slope (2:12 to 4:12), conventional slope (4:12 to 8:12), or steep-slope (8:12 and above). Slope directly affects material selection, installation method, labor costs, and drainage performance.