Flood test
A flood test checks waterproofing membrane integrity in a wet area before tiling by filling the area with water and holding it for a set period.
Ask Chalkline about this →A flood test is a pre-tile inspection method used to verify the integrity of a waterproofing membrane in a wet area before tiling proceeds. The waste is temporarily plugged, the area (typically a shower or bathroom floor) is filled with water to a nominated depth, and held for a specified period (typically 24 hours). If the water level holds without dropping, the membrane has passed. If the water level drops, a breach exists and must be located and repaired before tiling.
Flood testing is standard practice on residential wet areas in Australia. It is the builder’s quality assurance gate between the waterproofer’s work and the tiler’s work. A passed flood test should be confirmed in writing (or photographed) before the tiler is allowed on. Tiling over an untested or failed membrane means any defect discovered post-tile requires full tile strip and re-waterproofing.
Also known as: water test, flood testing.
Category: On-site inspection.
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Last updated: 2026-05-10. Verified: 2026-05-10. Quarterly review for currency.