Minimum Roof Slope For Flat Roof

Match roof material and use appropriate slope match the roofing on the covered porch with the main roof.

Minimum roof slope for flat 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. Determine the minimum slope of the roof based on the roofing material. In general the minimum slope for a flat roof is 1 0 but as stated earlier this is only possible in theory. 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.

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

According to the 2012 international building code 1507 4 2 deck slope minimum slopes for roof panels need to comply with the following. 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. This means for every 12 horizontal units the roof must rise a minimum of 3 vertical units. The minimum slope of a roof depends on the roof s profile.

Asphalt shingles continue to be the most widely installed roof covering option in north america. This is the basis for calculating the angle which is approximately a 1 19 degree slope. 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. The following table provides the minimum required allowable roof slope for each type of roofing material mentioned in the code.

The profile is the shape taken by the sheets when you bend them to form panels. Express the slope of a metal roof by a ratio which indicates the pitch of the roof.