Minimum Roof Slope Angle

A quarter inch slope is the lowest you would go with a metal roof experts recommend at least a half inch minimum to ensure a weatherproof interior for your shed.

Minimum roof slope angle.

The minimum pitch for a standing seam metal roof is 1 4 or 3 inches rise to 12 inches run. The profile is the shape taken by the sheets when you bend them to form panels. The minimum slope of a roof depends on the roof s profile. The following tableprovides the minimum required allowable roof slope for each type of roofing material mentioned in the code.

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 requirements for an asphalt shingles roof are contained in the international building code. The minimum pitch for shingles is 1 6 which is equivalent to 4 inches rise to 24 inches run.

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. Lap sealants shall be applied in accordance with the approved manufacturer s installation instructions. Express the slope of a metal roof by a ratio which indicates the pitch of the roof. According to this code the minimum slope for asphalt shingles is 17 degrees or two vertical units to twelve units in the horizontal.

The short simple answer is 2 12 has traditionally been considered the absolute minimum acceptable roof slope suitable for asphalt shingles. Remember metal roofing is more expensive than shingles. Minimum roof slope roof pitch r905 15 1 liquid applied roofing must have a design roof slope of 1 4 12 or greater 2 slope. The minimum slope for standing seam of roof systems shall be one quarter unit vertical in 12 units horizontal 2 percent slope.

The minimum pitch is typically 3 12 meaning the roof should rise 3 inches for every 12 inches of horizontal foot. The standard of lower pitch actually ranges between 1 12 to 5 12. The metal roof minimum slope doesn t stray far from other building with different material. Roof slope equivalents as rise.

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.