Roof Slope Requirements

Asphalt shingles continue to be the most widely installed roof covering option in north america.

Roof slope requirements.

The basic object of the house or home is to provide shelter. Amongst many decisions one has to make when designing a metal building determining metal roof minimum slope is one of them. In roof construction a roof is covered by covering materials which are supported on a structural member. The minimum pitch for.

Minimum slope for asphalt shingles the requirements for an asphalt shingles roof are contained in the international building code. According to this code the minimum slope for asphalt shingles is 17 degrees or two vertical units to twelve units in the horizontal. The roof is the uppermost portion of the building. Cricket angles slopes are to be constructed to maintain positive slope drainage the entire distance of the valley.

It determines how many inches the roof should rise for every 12 inches expanding on the horizontal side. The roofs can be either flat or sloping. Roof pitch is the degree of building s roof slope. The short simple answer is 2 12 has traditionally been considered the absolute minimum acceptable roof slope suitable for asphalt shingles.

Determine the minimum slope of the roof based on the roofing material. A roof must be strong to withstand snow and wind load. Crickets should be installed behind all curbs that obstruct drainage. Slope should be built into the structure on new buildings.

Roof slope of 1 4 per foot minimum is required on all roof systems. In cases of roof system replacement and re cover of existing low slope roof systems ibc 2018 and irc 2018 waive the codes 1 4 12 minimum slope requirement and apply a performance based positive roof drainage minimum requirement. Roof slope equivalents as rise. Run in degrees and as percentage the minimum roof slope allowed by code for any type of roofis in 12 applicable only to coal tar pitch roof systems.

Match roof material and use appropriate slope match the roofing on the covered porch with the main roof. When required for steep slope roofs section 1507 in the ibc and section r905 1 2 of the irc specify the use of an ice barrier that consists of either two layers of underlayment cemented together or a self adhering polymer modified bitumen sheet at eaves and valleys. This means for every 12 horizontal units the roof must rise a minimum of 3 vertical units.