The short simple answer is 2 12 has traditionally been considered the absolute minimum acceptable roof slope suitable for asphalt shingles.
Minimum slope for aluminum flat roof.
Flat roof slope minimum 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.
The minimum roof slope for metal roofs is dependent upon the roof profile.
Lapped nonsoldered seam metal roofs without applied lap sealant must have a minimum roof slope of 3 12 25 slope.
The minimum roof slope allowed by code for any type of roof is in 12 applicable only to coal tar pitch roof systems.
For the most part the minimum pitch for metal roof installations depends on what kind of material you are installing and the method in which the material is being fastened.
The following table provides the minimum required allowable roof slope for each type of roofing material mentioned in the code.
Corrugated metal roofing has the same minimum pitch.
To get the minimum pitch for a metal roof the vertical rise per foot is divided by the horizontal slope.
Typically large footprint single story.
Low slope metal roofs require less material which reduces the overall load on the building s structure.
With regards to metal roofing the profile refers to the shape adopted by the metal sheets when they are bent to form the panels.
Asphalt shingles continue to be the most widely installed roof covering option in north america.
They provide excellent weather resistance great value and now more than ever a tremendous range of beautiful designs and color blends.
Determine the minimum slope of the roof based on the roofing material.
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.
The minimum roof slope for metal roof panels depend on 3 different scenarios.
According to the 2012 international building code 1507 4 2 deck slope minimum slopes for roof panels need to comply with the following.
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.
The minimum pitch for metal roof shingles and lapped non soldered panels is 3 12.
Minimum metal roof slope depends on the roof profile building design climate and site location.
Minimum pitch for metal roof.
This means for every 12 horizontal units the roof must rise a minimum of 3 vertical units.