Minimum Roof Pitch For Fiberglass Shingles

The minimum roof slope allowed by code for any type of roof is in 12 applicable only to coal tar pitch roof systems.

Minimum roof pitch for fiberglass shingles.

Clay and concrete tile requires a minimum roof pitch of 2 1 2 12 or greater. Normal roof slope for typical installation. This number corresponds to the number of inches of rise in a 12 foot run. 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. Normal shingle installation is allowed for all roofs with a pitch of 4 12 and above. Metal roof shingles require a minimum roof pitch of 3 12 or greater. If 4 12 and above is normal and 2 12 is minimum what about properties with roofs in between the two such as a 3 12 pitched roof.

Slate and slate type shingles require a minimum roof pitch of 4 12 or greater. Asphalt felt paper that is tacked to the roof sheathing. We do install shingles on these in between. Mineral surfaced roll roofing requires a minimum roof pitch of 1 12 or greater.

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. The short simple answer is 2 12 has traditionally been considered the absolute minimum acceptable roof slope suitable for asphalt shingles. All asphalt shingle roofs with a pitch of 4 12 or more have an underlayment of 15 lb. The following table provides the minimum required allowable roof slope for each type of roofing material mentioned in the code.