Minimum Roof Pitch For Flat Roof

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 pitch for flat roof.

Minimum metal roof slope depends on the roof profile building design climate and site location. Wood shingles require a minimum roof pitch of 3 12 or greater. For example a roof that rises 3 inches for every 12 inches has a pitch of 3 12. 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 for metal roofs is dependent upon the roof profile. To get the minimum pitch for a metal roof the vertical rise per foot is divided by the horizontal slope. To calculate roof pitch take the lowest point of the roof and measure the amount of rise for every 12 inches of horizontal movement toward the highest point. Wood shakes require a minimum roof pitch of 3 12 or greater.

A low pitched roof is easier to put up and maintain but may show very little of its material at ground level. Low slope roofs are not totally flat their roof slope generally ranges from 1 4 12 to 3 12. This is the basis for calculating the angle which is approximately a 1 19 degree 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.

In order to achieve this drop a slightly steeper angle of 1 40 1 44 should be the aim when installing a flat roof as this accounts for surface. However you can only use this pitch with built up roofing or specialized synthetic roofing. Slate and slate type shingles require a minimum roof pitch of 4 12 or greater. The profile refers to the shape the metal sheets take when they bend to.

Minimum pitch for metal roof. Built up roofs require a minimum roof pitch of 1 4 12 or greater. The following table provides the minimum required allowable roof slope for each type of roofing material mentioned in the code. Depending on the roof profile there are minimum roof slope requirements for each panel which need to be considered.

With regards to metal roofing the profile refers to the shape adopted by the metal sheets when they are bent to form the panels. The minimum slope for standing seam of roof systems shall be one quarter unit vertical in 12 units horizontal 2 percent slope. They provide excellent weather resistance great value and now more than ever a tremendous range of beautiful designs and color blends. Mineral surfaced roll roofing requires a minimum roof pitch of 1 12 or greater.

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.