Cracks at window corners: when a buyer should bring in an engineer
Corner cracks, moderate slab cracks and failed sealant on houses near Truganina, and how a pre-purchase report treats them.
In short: Diagonal cracks from the corners of doors and windows are one of the clearest signs of movement. They do not always mean a failed footing, but they do change the questions a buyer should ask.
Why corners crack
Openings are the weak points in a wall. When the ground moves, stress concentrates at the corners of doors and windows, and cracks start there.
What we found next door
On an inspection in Deer Park in August 2026 we recorded cracking at the corners of doors and windows indicating soil movement, and slab cracks between 2mm and 4mm, beyond the tolerance.
When an engineer is needed
Cracks that are wide, growing or stepping through brickwork, or slab cracks beyond tolerance, need a structural engineer to assess their significance. A pre-purchase report flags them; it does not diagnose the footing.
Sealant and water
Failed sealant often appears alongside cracking, and water getting into the wall adds to the problem. Both are on the report.
What it means for your purchase
Major cracking does not automatically mean walk away. It means get the engineer's view, understand the likely cost, and negotiate or decide with that information.
Written by our local inspection team from work carried out in Truganina. Licensed building practitioners, Building & Plumbing Commission registration CDB-U 53425.
