Roof Pitch

Roof Pitch

The pitch of a roof refers to the angle of the roof, which is typically expressed as the number of inches of vertical "rise" over a 12-inch horizontal "run."

Minimum slopes for various roof coverings

The International Residential Code (IRC) outlines the minimum requirements for roof coverings and requires that the installation instructions provided by the manufacturer of the roof covering be followed.

According to the 2015 IRC R905,

Roofing materialRoof slopes
Asphalt shingles2:12 or greater
Built-up roofs0.25:12 or greater
Clay and concrete roof tiles2.5:12 or greater
Liquid-applied roofing0.25:12 or greater
Metal roofs without lap sealant3:12 or greater
Metal roofs with lap sealant0.5:12 or greater
Metal roof shingles3:12 or greater
Mineral-surfaced roll roofing1:12 or greater
Modified bitumen roofing0.25:12 or greater
Photovoltaic shingles2:12 or greater
Slate shingles4:12 or greater
Sprayed polyurethane foam roofing0.25:12 or greater
Thermoset single-ply roofing0.25:12 or greater
Thermoplastic single-ply roofing0.25:12 or greater
Wood shingles3:12 or greater
Wood shakes3:12 or greater

Walkability based on different Roof Slope

  • Roof having slope less than 6:12 (26.57°) is walkable.
  • Roof having slope 7:12 (30.26°) is walkable but caution is required.
  • On Roof having slope between 8:12 to 10:12 (33.69° to 39.81°), walking is not recommended. Extreme caution is required.
  • Roof having slope greater than 11:12 (42.51°) is too steep to walk on.Roof jacks, Scaffolding, affixed ladders etc. needed for installation, insection and repair.