Installs wood framing (floor, wall and roof systems)
Framing questions test load path, spacing, and the prescriptive rules that keep a platform-framed building straight, square and tied together. Expect basic span and layout reasoning rather than engineered design.
Floors
Floor joists are sized from span tables for the species, grade, spacing and load, and are carried on beams, bearing walls or hangers - not nailed to a ledger that has not been flashed. Bridging or blocking keeps deep joists from twisting and spreads load. Subfloor panels run across the joists with long edges supported, glued and screwed, joints staggered. Drilling and notching follow prescriptive limits: holes stay small, centred and away from top and bottom edges, and the middle third of a span is not notched.
Walls
Studs are laid out at 400 or 600 mm on centre from a control corner so sheathing edges land on framing; the last space is adjusted rather than left oversize. Openings get king studs, jack (trimmer) studs and a header sized for the span and the load above - a header in a bearing wall is larger than one in a non-bearing wall. Plates lap at corners and intersections, and fire blocking goes in where required at concealed spaces, dropped ceilings and floor levels.
Roofs
Roof framing runs ridge, common rafters or trusses, hips and valleys, with collar ties where the design requires them to resist thrust. Trusses are braced temporarily during erection and permanently per the truss drawing, and are never cut or modified on site. Hurricane ties and rafter anchors connect roof to wall and wall to floor, completing the load path. Roof sheathing is nailed to the required pattern, with a gap at the ridge for ventilation.
Worked example
A wall is 5.3 m long, framed at 400 mm o.c. 5.3 ÷ 0.4 = 13.25 → 13 spaces need 14 studs, but 13 × 400 mm = 5.2 m leaves a 500 mm end space. Recalculating: 5.3 ÷ 13 = 408 mm per space, so 14 studs fit with every space within the 400 mm requirement, and the first stud is set back half a stud width so the sheathing edge is supported.
Traps
Notching a joist midspan; omitting jack studs so the header bears only on the king stud; cutting a truss on site; and leaving the last stud space oversize.