If necessary use a sliding bevel to determine angles needed where the rafters will meet the ledger board.
Ledger board for roof rafters.
It is always better to have a large rafter rather than be concerned with a sagging roof.
Locate a position for a header or ledger board.
Locating and mounting the ledger is normally a fairly easy process.
Attach 2x6 rafters to the house with joist hangers and or supported by the ledger board.
Structures such as sheds or barns can be frames with rafters every 24 again make sure to consult local codes.
The ledger should be attached before the foundation is built for a deck patio roof posts and other structure.
For low pitch roofs building codes may require larger dimension rafters.
Determine how high it must be to provide an adequate slope to the roof.
Attach the rafters to the ledger boards and settle joists.
Attach the rafters to the house with joist hangers which supported by ledger boards.
As roof pitch is lowered the weight burden on the rafters increases.
Visit the roof framing page for more information on cutting roof rafters and visit the roof pitch calculator for determining rafter lengths based on rise and run.
Place the rafters on 24 centers attach them to the settle joists and beams toward the center.
For instance if your roof has a steep pitch you may be able to use 2 inch by 4 inch rafters but if your roof has a low pitch building code may require that you used 2 inch by 6 inch or 2 inch by 8.
If you ve wondered how to frame a lean to roof off a pole barn this video will show you how i did it.
The opposite side of the porch roof will be supported by a header beam that is installed parallel to the house on top of 6x6 support posts.
Rafter span tables use these tables to determine lengths sizes and spacing of rafters based on a variety of factors such as species load grade spacing and pitch.
If your project had a rafter length of 8 or less a safe and strong method is to use 2x8 framed 16 on center.
Make sure to check the vertical beam to ensure that the end rafters are placed securely.
If you are tying the roof directly to a house wall you can install a ledger board with flashing and install rafter ties to attach the rafters at the appropriate angles or use engineered trusses.
Find the wall studs or roof trusses that will have to support the ledger.
Rafters are placed on 24 centers and attached to the beams and settle joists are attached as needed image 1.