Internal Waterproofing: 11 Top Tips

The most recent changes to AS3740 (Domestic Wet Area Waterproofing) and the NCC 2022 are extensive. With so much detail required to achieve compliance, the end game as a contractor or builder is to eliminate building failure.

Therefore, my 11 top tips are as follows;

1.       Do not use WR (water resistant) plasterboard on shower/bath recess walls. Use Cement Sheet.

2.       Get a copy of AS3740:2021 and get familiar with the contents

3.       If you are a builder, get one trade contractor to own the waterproofing, tiling, and caulking

4.       Use digital measuring tools such as Empire Spirit Levels

5.       Get your waterstops in the correct position as it is a simple visual item for inspectors to pick on and rectification involves stripping the room and starting again

6.       Do not use Particleboard anywhere on the floor. Only use James Hardie Secura Scyon 19mm compressed cement sheet

7.       Do not use MDF mouldings in wet areas

8.       Inform your client that caulking has a lifespan of 5 years and must be maintained

9.       Get your fillets/bond breakers and bandaging right at cold joins. This joint is prone to building movement and therefore susceptible to splitting.

10.   If you are a waterproofer, leave a pre printed sign informing the tiler of the product used

11.   Always follow Product Installation Guides