The minimum roof slope for metal roofs is dependent upon the roof profile.
Minimum roof slope alberta.
The profile refers to the shape the metal sheets take when they bend to.
Use a membrane roofing system for roof slopes less than 4 12 1 3.
Extending from the edge of the roof a minimum of 900 mm up the roof slope to a line not less than 300 mm inside the inner.
Where the roof slope is less than 1 in 6 or in roofs that are constructed with roof joists the unobstructed vent area shall be not less than 1 150 of the insulated ceiling area.
To get the minimum pitch for a metal roof the vertical rise per foot is divided by the horizontal slope.
Metal roof shingles require a minimum roof pitch of 3 12 or greater.
Depending on the roof profile there are minimum roof slope requirements for each panel which need to be considered.
Cgsb ca cgsb 37 54 polyvinyl chloride roofing and waterproofing membrane national building code of canada 2005.
The minimum roof slope allowed by code for any type of roof is in 12 applicable only to coal tar pitch roof systems.
Division b part 5 page 5 11 the national building code now dictates that all flat roof deck and balcony areas are considered roofs and when specifying a pvc.
The minimum slope for standing seam of roof systems shall be one quarter unit vertical in 12 units horizontal 2 percent slope.
Let us recap on the minimum roof pitch required for each type of roofing material.
The following table provides the minimum required allowable roof slope for each type of roofing material mentioned in the code.
The alberta building code.
Asphalt shingles require a minimum roof pitch of 2 12 or greater.
The minimum pitch for a roof is 1 4 12 which translates to 1 4 inch rise to 12 inches of run.
Minimum pitch for metal roof.
Clay and concrete tile requires a minimum roof pitch of 2 1 2 12 or greater.
Use a membrane roofing system for roof slopes less than 4 12 1 3.
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 roof slope permitted for issuance of an asphalt shingle roofing warranty certificate is 4 12 1 3.
However you can only use this pitch with built up roofing or specialized synthetic roofing.
They provide excellent weather resistance great value and now more than ever a tremendous range of beautiful designs and color blends.
The short simple answer is 2 12 has traditionally been considered the absolute minimum acceptable roof slope suitable for asphalt shingles.