The slab
A 112.5 m² raft slab on Brisbane shale, with deep edge beams to handle the variable ground conditions. Total slab category cost $37,900, including earthworks, termite barrier, formwork, steel and concrete pump. The shale variability cost us a $2,200 variation on one corner.
Subfloor framing
Subfloor framing went in once stumps were set and the slab cured. Costed inside the raise-and-subfloor category at $18,000. Coordination with the engineer and certifier through this stage is critical: hold points sit between framing and the next inspection.
Posts and bracing
The original Queenslander posts were assessed, retained where structurally sound, and replaced where needed. Engineering specified the bracing pattern across the new lower level. Modern bracing requirements on a 100-year-old structure require engineering work you don't see in the budget until the certifier flags it.
Engineering hold points
Engineering hold points across the structural sequence: slab, subfloor frame, wall frame, roof tie-down. Each requires a certifier inspection and engineer sign-off before the next trade arrives. Missing a hold point delays you a week.
