Rafters are the beams that run just under the roof of a home and represent the roof's angle. Joists are the horizontal beams that run just above the ceiling and anchor the rafter. Where these two housing frame components meet, they must be attached securely in order to ensure the stability and longevity of the roof.
Things You'll Need
- Table saw
- Wood nails
- Wood screws
Check the angle of the joists to ensure they are horizontal before attaching them to the rafter. Lay a water level on the top of the joist or check the angle with a laser level. If the joist does not sit perfectly level, then the wall heights must be corrected before the joists are attached.
Ensure that the ends of the joists that may project above the rafter are trimmed off before attaching the joists to the rafters. Use a table saw to cut off the angle that projects over the rafter.
Set the end of the joist on top of the wall (the other end of the joist should rest on the opposite wall). The trimmed edge of the joist should be up. Set the notched end of the rafter on the wall so that it sits flush with the top edge of the wall. Have a partner hold the rest of the rafter in place while you connect the joist and the rafter. The rafter and joist should sit flush against one another.
Attach a seismic anchor to the side of the rafter opposite the joist. Seismic anchors are joints with a 90-degree-angle twist that connect the rafters directly to the wall.
Nail the joist to the rafter. Use at least four nails per joist/rafter connection. Nails should be at least one and a half times the depth of the rafter and joist beams. Usually, these beams are 2-inches by 4-inches, and so the depth is 2 inches. Thus, the nails should be three inch long wood nails.
Test the rafter/joist attachment manually for stability by rocking it with your palm. For added stability, pre-drill holes for screws and anchor with 3-inch wood screws.
- "Residential Construction Academy: Carpentry"; Floyd Vogt; 2002
- Photo Credit new house image by Jim Dubois from Fotolia.com
How to Build Rafters
A rafter is a type of beam that structurally supports the roof of a building. Typically rafters are not built, they build...
How to Build Wooden Rafters for a Shed
Wooden rafters support the roof of a shed. They can be made out of 2-by-4 inch pieces of wood using a tape...
How to Put Up Trusses
Whether you are installing roof trusses for a room addition, or you are building an entire house, you will be able to...
How to Attach Fascia Board to Roof Trusses
Roof trusses are made up of rafters and ceiling joists. Rafters are cut in two pieces that are joined at an angle...
How to Frame a Gable Roof Without Ceiling Joists
A gable roof consists of two upward sloping sides that slope at the same angle and from the end look like a...
How to Install Joist Hangers on Rafters
Rafters are boards made of dimensional lumber. They are 2-by-8, 2-by-10 or 2-by-12 depending on personal preference and are installed to help...
How to Fasten Blocking to Rafters
Rafter blocking is an essential part of the roof framing process in that the blocks provide a stop for ceiling insulation and...