Minimum Roof Slope For Metal Roof

Typically large footprint single story.

Minimum roof slope for metal roof.

Profile in the context of metal roofing means the shape that the sheet of metal is bent into to form the panels. The minimum slope for lapped non soldered seam metal roofs with applied lap sealant shall be one half unit vertical in 12 units horizontal 4 percent slope. Low slope metal roofs require less material which reduces the overall load on the building s structure. Lapped nonsoldered seam metal roofs without applied lap sealant must have a minimum roof slope of 3 12 25 slope.

Low slope roofs are not totally flat their roof slope generally ranges from 1 4 12 to 3 12. 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. Minimum metal roof slope depends on the roof profile building design climate and site location. The minimum roof slope for metal roof panels depend on 3 different scenarios.

The metal roof minimum slope doesn t stray far from other building with different material. The pitch is measured in inches of vertical rise per foot of horizontal run and the 5v crimp profile shown above requires a minimum slope of three in twelve or 3 12 3 inches vertically per 12 inches horizontally. Lap sealants shall be applied in accordance with the approved manufacturer s installation instructions. To get the minimum pitch for a metal roof the vertical rise per foot is divided by the horizontal slope.

The minimum pitch is typically 3 12 meaning the roof should rise 3 inches for every 12 inches of horizontal foot. That is a 14 degree angle. The minimum roof slope allowed by code for any type of roof is in 12 applicable only to coal tar pitch roof systems. The minimum roof slope for metal roofs is dependent upon the roof profile.

The minimum slope for standing seam of roof systems shall be one quarter unit vertical in 12 units horizontal 2 percent slope. Moreover low slope metal roofs are not prone to the degradation experienced by organic materials enabling these roofs to better resist the elements. That means there is at least 3 of vertical rise to the roof slope for every 12 it goes back horizontally. This means for every 12 horizontal units the roof must rise a minimum of 3 vertical units.

In retrofit projects a sub framing system is attached to the existing flat roof surface to provide a minimum 12 roof pitch. The following table provides the minimum required allowable roof slope for each type of roofing material mentioned in the code.