In New Zealand, bathroom waterproofing is governed by NZS 4243 and the Building Code Clause E3. Whether you're doing a full renovation or just retiling, understanding waterproofing requirements is non-negotiable.
What Areas Need Waterproofing?
All wet areas within 1500mm of a shower or bath require waterproofing membrane to a minimum height of 1800mm on shower walls. Floor areas must be fully waterproofed.
Choosing the Right Membrane
There are three main types used in NZ residential work: sheet membranes, liquid-applied membranes, and cementitious coatings. For most renovations, a liquid-applied polyurethane or acrylic membrane offers the best combination of flexibility and durability.
Common Failure Points
Corners and junctions between floor and wall are where most waterproofing failures occur. Ensure adequate corner reinforcement tape is used and that the membrane is continuous with no gaps or holidays.