New Waterproofing Provisions

As of September 2023 the National Construction Code (NCC) has changed its standards arounds waterproofing.

The Housing Provisions have changed to require that surface finishes grade to every drain waste (that is any hole in the floor) in a wet area.

This applies regardless of whether the floor waste was required to be installed as a requirement of NCC 2022, or if the floor waste was installed voluntarily.

Queensland specific rules override the Housing Provisions Queensland Development Code (QDC) Mandatory Part (MP) 4.5 Livable dwellings and grading to floor wastes and states that:

• The wet area floor gradient to non-mandatory floor waste is now required to be between 1:80 and 1:00, overriding the NCC provision of a gradient between 1:50 and 1:80.

• However, the floor does not need to be graded to the non-mandatory floor waste if:

  • All vessels have in-built overflow protection, and flood stop safety valves are fitted to all flexible hose assemblies in the wet area; or

  • Each entrance to the wet area has a linear drain across the full entrance; or

  • Each entrance to the wet area has a weir extending across the entrance at least 10mm above the height of the floor waste and maximum gradient of 1:8 within the door jamb/ 100mm of door jamb.

[Refer to A5 of QDC MP4.5 for detailed requirements]

• The floor does not need to be graded if there is no floor waste.

• If an area of the floor is separated from the entrance by a graded area, that separated area does not have to be graded [refer figure A5(5) of QDC MP4.5].

Your can dowmlaod your copy of the QDC MP4.5 here