Minimum Roof Slope For Flat Roof

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

Minimum roof slope for flat roof.

You need to consider the slope requirements of each panel to determine this minimum slope. In general the minimum slope for a flat roof is 1 0 but as stated earlier this is only possible in theory. The minimum slope of a roof depends on the roof s profile. This means for every 12 horizontal units the roof must rise a minimum of 3 vertical units.

The minimum roof slope allowed by code for any type of roof is in 12 applicable only to coal tar pitch roof systems. The short simple answer is 2 12 has traditionally been considered the absolute minimum acceptable roof slope suitable for asphalt shingles. Minimum roof slope roof pitch r905 7 2 wood shingles can only be installed on roof slopes of 3 12 or greater 25 slope. Determine the minimum slope of the roof based on the roofing material.

The profile is the shape taken by the sheets when you bend them to form panels. Match roof material and use appropriate slope match the roofing on the covered porch with the main roof. It takes the manufacturer s recommendations the unique conditions of the roof as well as the skills and the expertise of the installer to arrive at the right slope. Normally 1 80 0 72 is the recommended minimum angle for a slope and this is universal across the vast majority of flat roofing systems regardless of the materials that they incorporate.

The minimum slope for lapped non soldered seam metal roofs without applied lap sealant shall be three units vertical in 12 units horizontal 25 percent slope. A 4 12 is a roof slope that rises by 4 inches for every 12 inches across. The following table provides the minimum required allowable roof slope for each type of roofing material mentioned in the code. This forms an angle of 18 5 between the horizontal section and the roof and creates a gentle incline that is seen as a midpoint between a low pitch and medium pitch roof.

Flat roof slope minimum according to the international building code the typical built up flat roof that uses tar or asphalt goes by the guideline that for every foot 12 inches of a flat roof a minimum of inch must step up or down. This is the basis for calculating the angle which is approximately a 1 19 degree slope.