Minimum Roof Pitch For Standard Shingles
The minimum pitch is typically 3 12 meaning the roof should rise 3 inches for every 12 inches of horizontal foot.
Minimum roof pitch for standard shingles. The metal roof minimum slope doesn t stray far from other building with different material. That works out to about nine degrees if that works better for you. The 2 12 number is rise over run or two units of vertical for every 12 units horizontal. Asphalt felt paper that is tacked to the roof sheathing.
Shingles of all types need to have a slope to function properly. The standard of lower pitch actually ranges between 1 12 to 5 12. All asphalt shingle roofs with a pitch of 4 12 or more have an underlayment of 15 lb. However you can only use this pitch with built up roofing or specialized synthetic roofing.
Clay and concrete tile requires a minimum roof pitch of 2 1 2 12 or greater. These shingles are appropriate for pitches as low as 4 12 pitch all the way up to a 12 12. Asphalt shingles continue to be the most widely installed roof covering option in north america. 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.
The roofing materials most often used for these pitches include asphalt composite shingles. With regards to the pitch the building standard code bs 5534 recommends a minimum pitch of 20 0 for slate roofs. Asphalt shingles require a minimum roof pitch of 2 12 or greater. Let us recap on the minimum roof pitch required for each type of roofing material.
The minimum pitch for a roof is 1 4 12 which translates to 1 4 inch rise to 12 inches of run. 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. What is the minimum pitch slope of an asphalt shingle roof. You could also opt for a pvc flat roofing membrane.
The minimum requirement is 2 12. The following table provides the minimum required allowable roof slope for each type of roofing material mentioned in the code. The short simple answer is 2 12 has traditionally been considered the absolute minimum acceptable roof slope suitable for asphalt shingles. 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.
Metal roof shingles require a minimum roof pitch of 3 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.