Waterproof or Water Resistant

The Difference

Waterproof material, or construction, does not allow moisture to penetrate through it.

Water Resistant material, or construction, means it restricts moisture movement and will not degrade when it gets wet.

Where it matters

The Building Code of Australia (Volume Two – Table provides details of the ‘wet areas’ that are required to be water resistant or waterproof.

Below is a short summary:


  • Waterproof:  Floor, 150mm up walls, all wall and floor junctions, all penetrations.
  • Water Resistant: Walls up to 1800mm from floor.

Areas adjacent to showers

  • Waterproof:  Timber or particle floor, all wall and floor junctions.
  • Water Resistant: Concrete and cement sheet flooring.

Areas adjacent to baths and spas

  • Waterproof:  Timber or particle floor, tap and spout penetrations.
  • Water Resistant: Concrete and cement sheet flooring, exposed wall from 150mm above hob down,

Laundries and toilets

  • Waterproof:  Junction of fitting to wall, surface penetrations.
  • Water Resistant: 150mm above fitting where fitting is within 75mm of wall.


To me this seems a bit lightweight. . . . Over the past 40 years of homeownership I have experienced both an overflowing bath, and a broken laundry hose.

I would suggest you consider at the least extending the waterproofing to the whole of the bathroom and laundry floors.

A  floor drain  is also a good idea