Minimum Pitch For Flat Metal Roof

Minimum required roof slope for roofing materials.

Minimum pitch for flat metal roof.

In 12 0 25 in 12 1 19 built up roof coal tar pitch. 18 43 asphalt shingles with special underlayment requirements 2 in 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. In retrofit projects a sub framing system is attached to the existing flat roof surface to provide a minimum 12 roof pitch.

Most residential metal roofs require at least a 3 12 roof pitch and have no maximum roof pitch. Low slope metal roofs have simple geometries and are easier and less expensive to install that medium to steep slope roofs. Low slope metal roofs require less material which reduces the overall load on the building s structure. Most metal roofs will have minimum pitches of three in twelve but this might sometimes go down depending on whether there are special installation procedures issued by the manufacturer regarding that particular roofing material.

Moreover low slope metal roofs are not prone to the degradation experienced by organic materials enabling these roofs to better resist the elements. That said if you want to have a metal roof that is worth its weight in value that doesn t come with a ton of problems the minimum pitch for metal roof applications should be kept at around at least a 3 1 2 12 three and a half on 12 or above. To get the minimum pitch for a metal roof the vertical rise per foot is divided by the horizontal slope. Minimum metal roof slope depends on the roof profile building design climate and site location.

That is a 14 degree angle. Roofing material or system. However you can only use this pitch with built up roofing or specialized synthetic roofing. According to the 2012 international building code 1507 4 2 deck slope minimum slopes for roof panels need to comply with the following.

9 46 built up roof asphalt. 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. Minimum required slope x in 12 minimum required slope degrees asphalt shingles. Corrugated metal roofing has the same minimum pitch.

Low slope roofs are not totally flat their roof slope generally ranges from 1 4 12 to 3 12.