Why the floor tiles cracked: a Werribee investigation
Tiles peaking and cracking across a ground floor, traced to missing movement joints.
In short: When tiles lift and crack, the tiles are rarely the cause. The question is what stopped them from moving.
What the owner saw
Floor tiles on the ground floor and in the laundry had peaked and cracked, and the grout was discolouring.
What we found
The tiled area extended well beyond the spacing at which movement joints are required, and the correct joints were not present. The tiles had also been grouted hard against the walls instead of finished with a flexible sealant.
Why that matters
Tiles and the slab beneath them expand and contract with temperature and moisture. Without movement joints that stress has nowhere to go, so it lifts the tiles into a peak and cracks them.
What the repair involves
Replacing damaged tiles is not enough on its own. Movement joints must be cut in at the correct spacing and the perimeter sealed with a flexible material.
Using the report
The report was written for the owner and builder to agree the repair. If it had gone to VCAT, an expert witness report would have been needed.
Written by our local inspection team from work carried out in Werribee. Licensed building practitioners, Building & Plumbing Commission registration CDB-U 53425.
