The minimum roof slope allowed by code for any type of roof is in 12 applicable only to coal tar pitch roof systems.
Lowest pitch shingle roof.
It is important for shingle roofs to function properly and one method of ensuring that this is achieved is to observe the pitch requirements for the shingles.
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.
Normal shingle installation is allowed for all roofs with a pitch of 4 12 and above.
The asphalt shingle manufactures recommend that you install asphalt shingles on a recommended minimum of 4 in 12 or greater however most manufactures will warrant their shingles down to a 2 in 12 pitch if the recommended installation method is used.
Mineral surfaced roll roofing requires a minimum roof pitch of 1 12 or greater.
The recommended minimum roof pitch for shingles is 2 12 or simply two units of vertical rise to every twelve units of horizontal span.
Current as of august 2020 asphalt shingles are an effective roof covering material for sloped roofs that can be successfully used on slopes as low as 2 12.
You are required to have a double layer of asphalt saturated felt paper or a single layer of ice water shield under your.
Metal roof shingles require a minimum roof pitch of 3 12 or greater.
As well a slope of 4 12 is most commonly considered the lowest slope for standard shingle installations.
We do install shingles on these in between pitches but special application measures must be taken in this middle ground.
Manufacturers of asphalt shingles recommend a pitch of 4 12 or more but the absolute minimum pitch is 2 12.
As in all construction work paying attention to the little details can make all the difference between a long lasting trouble free project and one that results in callbacks and early failure never a good option with a new england roof.
So a 4 12 pitch roof rises 4 inches for every 12 inches of horizontal run.
Pitch is measured in inches of vertical rise of the roof over one foot 12 inches of horizontal run.
Wood shingles require a minimum roof pitch of 3 12 or greater.
Wood shakes require a minimum roof pitch of 3 12 or greater.
The following table provides the minimum required allowable roof slope for each type of roofing material mentioned in the code.
Installation on roof slopes below a 2 in 12 pitch is not recommended at all.