Wet Areas

Wet area walls may be concrete, or timber or steel framed. Each has different requirements.

On this page:

• timber and steel framing
• concrete and concrete masonry.

Timber and steel framing

Timber and steel framing must:

• have sufficient depth to install plumbing services (pipes)
• include dwangs and support for fixtures (e.g. wall-mounted WC, cabinets, built-in cistern, grab rails, plumbing outlets)
• be insulated on external walls
• have an appropriate level of treatment for the risk of water damage
• be sufficiently rigid for the selected finish.

Framed walls are not good sound insulators – wall linings need to be carefully considered and specified to reduce sound travelling from bathrooms to other parts of the house.

Steel frames must include a thermal break on external faces of the framing on exterior walls.

Concrete and concrete masonry

Concrete and concrete masonry provide a firm base for wet area finishes such as plaster, terrazzo and tiles. They must:

• for concrete masonry and plastered finishes, have a waterproof finish to prevent moisture absorption (e.g. paint finish in accordance with E3/AS1) – a steel trowelled concrete surface finish is deemed impervious as for floors
• for exterior walls, meet the requirements of E3/AS1 and H1
• must have plumbing and electrical services pre-installed as they can’t easily be accommodated retrospectively.

^{Updated: 24 May 2016}