To keep the porch roof framing as simple as possible we installed a structural ridge supported by posts at each end with the common rafters landing on top of the ridge.
Pitch break shed roof rafter framing.
If you re framing a gable roof on a new house or building a shed or even a doghouse with a gable roof you ll need to cut a number of roof rafters.
For an 8 10 shed one sheet of plywood should be fine.
A 18 pieces of 2 4 lumber 92 long both ends cut at 30º rafters.
Before you cut your boards you ll need to measure the width of your building and calculate the exact length of each rafter.
You are going to cut out triangles that will cover the apex of each set of rafters.
A 9 pieces of 2 4 lumber 145 1 4 long cut at 60º at both ends bottom rafters.
Using a pitch measuring tool that i d made we also determined that the exact pitch of the shed roof was 3 1 2 in 12.
In order to build a roof for a large shed you needs the following.
2 4 rafters can span up to 7.
This example is for a roof with an 8 12 pitch.
Drip edge and felt paper.
Turn in a set of building blueprints with a pitch less than 3 12 or build a shed style roof with a low pitch and your building inspector will not pass the construction and provisions will have to be made to get the pitch up to acceptable standards if it is going to be shingled.
The roof rafters provide integral structural support to the roof.
Spacing your 2 4 shed rafters at 24 on center limits the width of your roof.
Pitch break shed roof rafter calculator.
Using the law of sines c a sin c sin a c shed roof rafter length c1 90 shed roof pitch angle c2 90 main roof pitch angle shed roof pitch angle c 90 shed roof pitch angle 90 main roof pitch angle shed roof pitch angle c c1 c2 a main roof pitch angle shed roof pitch angle a shed roof run shed roof rafter length shed roof run sin 90 shed roof pitch angle 90 main roof pitch angle.
The roof on this shed is a 4 in 12 slope which makes it a 18 and one half degree angle on the board ends.
Corbett grace their parents and even their kids are learning a lot about the many ways a few right many wrong to build a high performance home.
Rafter layout with a framing square.
Board to length with the ends angled properly and then to mark and cut the birds mouth and seat on the rafter.
For heavy loads 2x4s can span up to 5.
Position the square with both the 8 inch on the outside edge of the tongue and the 12 inch on the blade on the upper edge of the board.
The ridge end of the rafter and often the eve end will need to be cut to the angle of the roof slope.
Blind valleys simplify framing.
Most roof framing is 24 on center and you can still build sheds up to 14 with 2 4 rafters at 24 on center.
For light load roofs 24 o c.
A 18 pieces of 2 4 lumber 20 3 4 9 pieces of 2 4 lumber 38 1 2 long intermmediate rafters.