Most residential metal roofs require at least a 3 12 roof pitch and have no maximum roof pitch.
Minimum roof slope for metal roof.
The minimum roof slope for metal roof panels depend on 3 different scenarios.
Low slope roofs are not totally flat their roof slope generally ranges from 1 4 12 to 3 12.
Minimum metal roof slope depends on the roof profile building design climate and site location.
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.
Low slope metal roofs require less material which reduces the overall load on the building s structure.
Typically large footprint single story.
The following table provides the minimum required allowable roof slope for each type of roofing material mentioned in the code.
Minimum pitch for metal roof.
To get the minimum pitch for a metal roof the vertical rise per foot is divided by the horizontal slope.
That is a 14 degree angle.
Moreover low slope metal roofs are not prone to the degradation experienced by organic materials enabling these roofs to better resist the elements.
This means for every 12 horizontal units the roof must rise a minimum of 3 vertical units.
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 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.
Lap sealants shall be applied in accordance with the approved manufacturer s installation instructions.
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 pitch is typically 3 12 meaning the roof should rise 3 inches for every 12 inches of horizontal foot.
In retrofit projects a sub framing system is attached to the existing flat roof surface to provide a minimum 12 roof pitch.
That means there is at least 3 of vertical rise to the roof slope for every 12 it goes back horizontally.
The minimum roof slope for metal roofs is dependent upon the roof profile.
Profile in the context of metal roofing means the shape that the sheet of metal is bent into to form the panels.
Lapped nonsoldered seam metal roofs without applied lap sealant must have a minimum roof slope of 3 12 25 slope.