Type of roofing minimum slope maximum slope asphalt shingles low slope application 1 in 6 no limit.
Minimum roof slope bc.
The minimum slope for standing seam of roof systems shall be one quarter unit vertical in 12 units horizontal 2 percent slope.
2 asphalt and gravel or coal tar and gravel roofs may be constructed with lower slopes than required in sentence 1 when effective drainage is provided by roof drains located at the lowest points on the roofs.
The code provides minimum slopes for various types of roofing in table 9 27 3 a.
There are no minimum slopes given for gutters and this becomes a separate issue.
The minimum pitch for a roof is 1 4 12 which translates to 1 4 inch rise to 12 inches of run.
The following table provides the minimum required allowable roof slope for each type of roofing material mentioned in the code.
1 see sentence 9 26 3 1 2.
Notes to table 9 26 3 1.
To get the minimum pitch for a metal roof the vertical rise per foot is divided by the horizontal slope.
The minimum roof slope allowed by code for any type of roof is in 12 applicable only to coal tar pitch roof systems.
2 see sentence 9 26 3 1 3.
Depending on the roof profile there are minimum roof slope requirements for each panel which need to be considered.
Roof slope to a point equal in height to the flashing on the masonry but not less than 1 5 times the shingle exposure.
Asphalt shingles can be applied as low as 2 12.
However below 4 12 a superior underlay is required.
Cedar is available down to 4 12 for shakes and 3 12 for shingles.
However you can only use this pitch with built up roofing or specialized synthetic roofing.
The profile refers to the shape the metal sheets take when they bend to.
It further gives installation methods which it considers will ensure acceptable performance at these minimum slopes.
3 profiled metal roof cladding systems specifically designed for low slope applications are.
The minimum roof slope for metal roofs is dependent upon the roof profile.
The values given here.
The short simple answer is 2 12 has traditionally been considered the absolute minimum acceptable roof slope suitable for asphalt shingles.
With regards to metal roofing the profile refers to the shape adopted by the metal sheets when they are bent to form the panels.
There are fewer options when the roof slope approaches 2 12.
They provide excellent weather resistance great value and now more than ever a tremendous range of beautiful designs and color blends.
Asphalt shingles continue to be the most widely installed roof covering option in north america.
