A lean to roof also called a shed roof slopes in one direction with rafters that rest against another structure at their high end and overhang support posts or an exterior wall at their low end.
Rafter lean to roof.
The roof rafters provide integral structural support to the roof.
You can use common rafters on any shed roof but they make the most sense when constructing a gable roof or lean to type shed roof where they can sit on or attach to top plates of a wall.
In other words if there is a 1 1 2 ridge board nailed into the wall and the width of the lean to is 96 then the run will be 94 1 2 96 1 1 2 94 1 2.
Lean to rafters then connect to a ledger board against a wall of another shed or house.
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.
Before you cut your boards you ll need to measure the width of your building and calculate the exact length of each rafter.
Enter this measurement into the calculator and select a roof pitch and the length of the rafter will automatically returned along with the rise.
Rise and run means that a 6 12 pitch roof has 6 of rise vertical for each foot of run horizontal.