For roofs that won t experience heavy snow loads a gable roof can span up to 22 with 2 4 rafters.
How to build a 2 12 pitch roof.
This is a way of measuring the degree of steepness of the roof.
So use a tape measure to find the height of the roof above the top wall of the building.
Resilient asphalt shingles lie much flatter to the substrate than slate tile and concrete which keeps water from being easily blown under them.
A pitch of 2 12 is the minimum pitch for shingles made of asphalt so your roof just barely makes the cut off for one of the most popular roofing material options.
The pitch of a roof is the rise the vertical angle of the roof over the run the horizontal measurement.
Calculate the roof pitch.
The pitch of the roof is a ratio.
Pitch ratios range from 2 12 to 12 12.
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.
The number of inches that the roof rises vertically for every foot of roof.
You can use either 2 6 or 2 4 rafters for roofs with a 3 12 pitch or greater but it depends on the overall size of your shed.
For roofs that will experience heavy snow or wind and will span the same distance use 2 6 rafters.
Just enter the dimensions of the roof rise and run to get started.
If you re building rafters and aren t sure where to start when determining the length of your lumber you re in the right place our rafter stock size calculator shows you how long your rafters should be so you ll know what you need in terms of framing lumber dimensional lumber studs and more.
Most roof s have a pitch in the 4 12 to 9 12 range.