Floor Framing

A rim joist is end-nailed or toe-nailed to each joist. The joists, including the end joist parallel to the exterior walls, are toe-nailed to the sill plate (Figure 63). The inner portions of the joists are supported on top of load-bearing walls or intermediate beams (Figure 53), or framed into the side of the beam (Figure 54).

Figure 63

When a load-bearing wall runs parallel to the joists, it must be supported by a beam or load-bearing wall in the basement. Floor designs often require a load-bearing wall located at right angles to the floor joists, but offset from the joist support. Load-bearing interior walls at right angles to floor joists should be located not more than 900 mm (36 in.) from the joist support when the wall does not support a floor, and not more than 600 mm (24 in.) from the joist support when the wall supports one or more floors, unless the joist size is designed to support such concentrated loads.

Non-load-bearing partitions parallel to the joists should bear on joists or on blocking between the joists. The blocking should be 38 × 89 mm (2 × 4 in. nominal) lumber spaced 1.2 m (4 ft.) or less on centre.

Source : Canada Mortgage and Housing Corporation (CMHC)