How Much Slope For Metal Roof

According to this code the minimum slope for asphalt shingles is 17 degrees or two vertical units to twelve units in the horizontal.

How much slope for metal roof.

Typically low slope metal roof systems vary in weight from 40 to 135 pounds per 100 square feet making them among the lightest roofing products and the easiest to install. Some slight overhang is recommended in conjunction with a drip edge flashing to prevent water from getting under the roofing and onto underlying wood. Pitch is thus the ratio of the rise in inches to a 12 inch run and is often expressed using a semicolon for example 6 12. The minimum pitch for roll roofing is 2 12 or 2 inches rise to 12 inches run.

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. In my opinion accurate slope for metal roof systems is in excess of 2 1 2 12. 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.

Standing seam metal roofs with mechanical lock systems to ward off leaks can be successfully and attractively installed on roofs with at least a slope of 1 in 12. In case a slope greater than this is necessary then a double underlayment application must be used as per the requirements of the international building code. Metal is usually installed on rafters or strip sheathing rather than the solid decking used under other materials. Roof pitch or slope is a measure of vertical rise to horizontal run expressed in inches per foot.

A typical metal roof overhang may be 2 to 4 inches or even less. A lightweight roofing system also places fewer demands on a building s structural support system an important consideration in earthquake prone areas. Low slope roofs are not totally flat their roof slope generally ranges from 1 4 12 to 3 12. The minimum pitch for a standing seam metal roof is 1 4 or 3 inches rise to 12 inches run.

Profile in the context of metal roofing means the shape that the sheet of metal is bent into to form the panels. Generally speaking if the waterproofing capacity of metal were sufficient in low slope applications why would the industry apply. A a roof with a 6 rise for every 12 run has a 6 per foot or 6 in 12 pitch. Lap sealants shall be applied in accordance with the approved manufacturer s installation instructions.

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. A steep slope allows for the fast run off of the moisture.