Platform Framing

This is a common framing method where each floor serves a work platform for building and erecting the walls for the next storey. End-nail the top and bottom plates to each stud with two nails at least 82 mm (31⁄4 in.) long. Apply wall sheathing to the framing prior to erection to eliminate the need for scaffolding for this operation. Some types of sheathing such as plywood and OSB will resist lateral loads and keep walls square. Others such as rigid glass-fibre, asphalt-coated fibreboard, polystyrene or polyurethane board will not, and walls need to be reinforced with diagonal wood or metal bracing let into the studs (Figure 68).

Once a wall section is ready, rotate it into the vertical position, add temporary braces and nail the bottom plates to the subfloor and floor framing members (Figure 68). The braces should have their larger dimension on the vertical and allow the vertical position of the wall to be adjusted so that it is plumb.

Once the wall sections are aligned and plumb, they are nailed together at the corners and intersections. When polyethylene is used for the air barrier system, a strip of the material should be placed between the interior walls and the exterior walls, and above the first top plate of interior walls before the second top plate is applied for later attachment and sealing to the rest of the air barrier

Interior partitions supporting floor, ceiling or roof loads are called load-bearing walls; others
are called non-load-bearing or simply partitions. Interior load-bearing walls are framed in the
same way as exterior walls. Studs are usually 38 × 89 mm (2 × 4 in. nominal) lumber spaced at 400 mm (16 in.) on centre. This spacing may be changed to 300 mm (12 in.) or 600 mm (24 in.) depending on the loads supported and the type and thickness of the wall finish used.

Partitions can be built with 38 × 64 mm (2 × 3 in. nominal) or 38 × 89 mm (2 × 4 in. nominal) studs spaced at 400 or 600 mm (16 or 24 in.) on centre depending on the type and thickness of the wall finish used. Where a partition does not contain a swinging door, 38 × 89 mm (2 × 4 in. nominal) studs at 400 mm (16 in.) on centre are sometimes used with the wide face of the stud parallel to the wall. This is sometimes done for partitions enclosing closets to save space.

Since there is no vertical load to be supported by partitions, single studs may be used at door openings. The top of the opening may be bridged with a single piece of 38 mm (2 in. nominal) lumber the same width as the studs. These members provide a nailing support for wall finishes, door frames and trim.

Source : Canada Mortgage and Housing Corporation (CMHC)