Allowable shingle exposure may also vary by the shingle grade something that you might infer by visual inspection of the shingles matching against wood shingle grade definitions or.
Minimum slope for wood shingle roof.
Wood shakes can only be installed on roof slopes of 3 12 or greater 25 slope.
The following table provides the minimum required allowable roof slope for each type of roofing material mentioned in the code.
Built up roofs minimum roof slope roof pitch r905 9 1.
The minimum roof slope allowed by code for any type of roof is in 12 applicable only to coal tar pitch roof systems.
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.
Nrca s recommended minimum roof slope guidelines for steep slope roof systems generally are greater at steeper inclines than those in the building code.
Low sloped roof shingle installation.
Asphalt shingles continue to be the most widely installed roof covering option in north america.
Normal roof slope for typical installation.
Normal shingle installation is allowed for all roofs with a pitch of 4 12 and above.
Underlayment for asphalt shingles clay and concrete tile metal roof shingles mineral surfaced roll roofing slate and slate type shingles wood shingles wood shakes and metal roof panels shall conform to the applicable standards listed in this chapter.
The short simple answer is 2 12 has traditionally been considered the absolute minimum acceptable roof slope suitable for asphalt shingles.
This means for every 12 horizontal units the roof must rise a minimum of 3 vertical units.
Underlayment materials required to comply with astm d226 d1970 d4869 and d6757 shall bear a label indicating compliance to the standard.
Why is 2 12 the minimum.
There are differing opinions as to the minimum slope for a roof but the generally accepted minimum is 3 12.
For asphalt shingle clay and concrete tile metal shingle slate and wood shake and shingle roof systems nrca recommends slopes of 4 12 or more.
The minimum slope for an asphalt shingle roof is 2 12.
The maximum weather exposure for wood shakes or wood shingles depends on the shingle size and the slope or pitch of the roof.
Wood shakes minimum roof slope roof pitch r905 8 2.
The roof pitch between 2 12 and 4 12 is considered as a low pitch roof so shingles can be installed in the roof slope between 2 12 and 4 12.
They provide excellent weather resistance great value and now more than ever a tremendous range of beautiful designs and color blends.
For example if it is a very low slope water including snowmelt or.
For example a shingle roof in a snowy region could be 2 12 but it is better to have a steeper.
This number corresponds to the number of inches of rise in a 12 foot run.
Some people recommend not installing asphalt shingles on slopes below 5 12 but a skilled roofer may well be able to make this work.