All asphalt shingle roofs with a pitch of 4 12 or more have an underlayment of 15 lb.
Minimum roof pitch for standard shingles.
Clay and concrete tile requires a minimum roof pitch of 2 1 2 12 or greater.
With regards to the pitch the building standard code bs 5534 recommends a minimum pitch of 20 0 for slate roofs.
The 2 12 number is rise over run or two units of vertical for every 12 units horizontal.
The roofing materials most often used for these pitches include asphalt composite shingles.
You could also opt for a pvc flat roofing membrane.
What is the minimum pitch slope of an asphalt shingle roof.
But since there is still a wide variety of slate roofing systems there are occasions when the minimum pitch can go down to as low as 15 0 depending on the uniqueness of the roof.
Traditional 3 tab shingles made with asphalt composite are the most popular type of shingle and are the most flexible in terms of adapting to many roof pitches.
But shingle roofing is not watertight in the sense that standing water or wind driven water on a low slope roof can work its way up between the laps which is the reason for the minimum 2 12 slope.
However you can only use this pitch with built up roofing or specialized synthetic roofing.
Let us recap on the minimum roof pitch required for each type of roofing material.
Asphalt shingles require a minimum roof pitch of 2 12 or greater.
The short simple answer is 2 12 has traditionally been considered the absolute minimum acceptable roof slope suitable for asphalt shingles.
Metal roof shingles require a minimum roof pitch of 3 12 or greater.
The standard of lower pitch actually ranges between 1 12 to 5 12.
That works out to about nine degrees if that works better for you.
Asphalt felt paper that is tacked to the roof sheathing.
Shingles of all types need to have a slope to function properly.
There are some standing seam metal roofing options available from atas and other manufacturers that can be installed on a roof with pitch of 1 12.
So you would need to pick the right option as most regular standing seam metal roofs will require a roof pitch of 2 12 or even 3 12 at a minimum.
The minimum pitch is typically 3 12 meaning the roof should rise 3 inches for every 12 inches of horizontal foot.
They provide excellent weather resistance great value and now more than ever a tremendous range of beautiful designs and color blends.
The following table provides the minimum required allowable roof slope for each type of roofing material mentioned in the code.
The minimum pitch for a roof is 1 4 12 which translates to 1 4 inch rise to 12 inches of run.
The metal roof minimum slope doesn t stray far from other building with different material.
The minimum requirement is 2 12.
