Re-entrant reinforcement, and the corner that cracks without it
Diagonal steel at internal corners, doing one specific job.
In short: Re-entrant corner reinforcement not installed on Oran Park slabs.
What a re-entrant corner is
An internal corner in the slab outline, where an L-shaped or stepped footprint turns back on itself.
Why it needs steel
Shrinkage stress concentrates at that geometry as the concrete cures. Diagonal bars spread it so the slab does not relieve the stress by cracking.
What we recorded
Re-entrant reinforcement not installed on Oran Park pours, on more than one job.
What happens without it
A crack running diagonally out from the corner. Rarely structural, frequently visible through the floor covering, and awkward to argue about later.
Timing
Pre-pour, alongside cover, beam widths and the vapour barrier.
Written by the Owner Inspections team from inspections carried out in Oran Park. Licensed building practitioners, NSW Fair Trading licence 366177C.
