How long should bathroom waterproofing last?

Membranes are not a consumable in the way grout or silicone are. Sitting under tiles, protected from ultraviolet light and from foot traffic, a compliant membrane on a properly prepared substrate has no obvious wear mechanism. So a bathroom leaking at five years is telling you something about how it was built.

What actually causes early failure

• Insufficient membrane thickness, usually from one coat where the product required two.
• No bond breaker at internal corners and junctions, so the membrane tears when the building moves.
• Poor substrate preparation, including dust, moisture or an incompatible primer.
• Penetrations, particularly the floor waste and tap bodies, not properly sealed into the membrane.
• Insufficient fall to the waste, so water sits on the membrane rather than draining.
• Tiling started before the membrane had cured.

Why it matters for a claim

Waterproofing is among the most common defects in Australian residential construction. Because early failure is a defect rather than wear, it usually falls within statutory warranty periods, which in most states run longer for structural or major defects. Establishing the installation date and who did it is therefore the first practical step, not the repair quote.