What is the minimum pitch slope of an asphalt shingle roof.
Minimum roof pitch michigan.
The minimum requirement is 2 12.
The short simple answer is 2 12 has traditionally been considered the absolute minimum acceptable roof slope suitable for asphalt shingles.
For roof slopes from two units vertical in 12 units horizontal 17 percent slope and up to four units vertical in 12 units horizontal 33 percent slope underlayment shall be two layers applied in the following manner.
Rise multiplier rise multiplier 1 to 12 1 01 6 to 12 1 12 2 to 12 1 01 8 to 12 1 20 3 to 12 1 03 12 to 12 1 42 4 to 12 1 06 15 to 12 1 60 5 to 12 1 08 18 to 12 1 80.
The minimum slope for standing seam roof systems shall be one quarter unit vertical.
That works out to about nine degrees if that works better for you.
Roof slope multipliers for roof components of sloping roofs multiply by the figures given below to obtain the cost per square foot of horizontal projection.
However you can only use this pitch with built up roofing or specialized synthetic roofing.
Apply a minimum 19 inch wide 483 mm strip of underlayment felt parallel with and starting at the eaves fastened sufficiently to hold in place.
You could also opt for a pvc flat roofing membrane.
Lap sealants shall be applied in accordance with the approved manufacturer s installation instructions.
The minimum roof pitch is also subject to the standards set forth by the various building codes used in the respective regions.
This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement.
The picture below shows the pitch of a 7 12 roof slope meaning that for 12 of horizontal measurement roof run the vertical measurement roof rise is 7.
They provide excellent weather resistance great value and now more than ever a tremendous range of beautiful designs and color blends.
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.
Importance of a roof pitch.
The chief reason for having a roof pitch is to redirect water and snow away from the roof and avoid any percolation that might result from stagnation of water on the roof.
The minimum pitch for a roof is 1 4 12 which translates to 1 4 inch rise to 12 inches of run.
So you would need to pick the right option as most regular standing seam metal roofs will require a roof pitch of 2 12 or even 3 12 at a minimum.
The 2 12 number is rise over run or two units of vertical for every 12 units horizontal.