Roof Rafters And Ceiling Joists

Rafters form the foundation for attachment of the roof boards onto which the final roof covering is fixed.

Roof rafters and ceiling joists. This board forms the bottom member of each rafter and of course the ceiling of the space below. Rafter ties or ceiling joists acting as rafter ties are required by code unless the house is designed so that the walls or a structural ridge beam carries the full load of the roof. Assuming that your builders have chosen to use wood for your house s frame your roofing joists ceiling joists rafters or trusses will be made from long planks of wood placed parallel to one another at evenly spaced intervals along the length of your roof. In this design the tops of the rafters attach to a load bearing ridge beam that runs along the length of the roof.

The joists might then be covered with osb or plywood to form an attic floor for storage. Use this table to determine the maximum lengths of ceiling joists based on species of lumber joist spacing and joist size. 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. If you are framing a cathedral ceiling there are a couple ways to deal with the need for rafter ties.

In unfinished space an attic insulation is typically laid between the joists. A structural ridge is the standard alternative to ceiling joists. The are similar to trusses in this regard. Rafter spans can be extended slightly beyond what the rafter tables suggest when there is a cantelever extending beyond the supporting wall.