The minimum roof slope allowed by code for any type of roofis in 12 applicable only to coal tar pitch roof systems.
Min roof pitch ny.
I e 4 inches of rise per 12 inches one foot of run.
Nonclassified roof coverings shall be permitted on buildings of group r 3 and group u occupancies where there is a minimum fire separation distance of 6 feet measured from the leading edge of the roof.
You could also opt for a pvc flat roofing membrane.
The minimum pitch for a roof is 1 4 12 which translates to 1 4 inch rise to 12 inches of run.
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.
With regards to the pitch the building standard code bs 5534 recommends a minimum pitch of 20 0 for slate roofs.
However you can only use this pitch with built up roofing or specialized synthetic roofing.
The minimum requirement is 2 12.
If a roof slope rises say 4 inches when measured 12 inches along the bottom of a horizontal roof truss the roof slope is said to be 4 12.
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.
Shingles of all types need to have a slope to function properly.
What is the minimum pitch slope of an asphalt shingle roof.
The following tableprovides the minimum required allowable roof slope for each type of roofing material mentioned in the code.