One of the more contentious issues in relation to bathroom construction is the provision of floor wastes and when they are required. There is much anecdotal evidence out there in relation to this, but what are the facts?
There are two primary documents in relation to wet areas construction:
- the Building Code of Australia (BCA) 2008 and
- AS 3740 – 2004 ‘Waterproofing of wet areas within residential buildings’ is the relevant Australian Standard referenced by the BCA.
Both contain information on materials and methods required in relation to waterproofing bathrooms and wet areas such as WCs and laundries.
The BCA has two parts: Volume 1 for Class 2 - 9 buildings and Volume 2 ‘Housing Provisions’ for Class 1 and 10 buildings.
AS 3740 contains the wet area provisions relevant for Class 1 buildings (houses), residential buildings, such as apartments, and commercial buildings.
The diagrams in AS 3740 indicate floor wastes for floor areas outside the shower enclosure for buildings that require this. The information in AS 3740 was subsequently transferred into BCA Volume 2 for houses unaltered and because of this it may be assumed that floor wastes are required in houses, but this is not strictly the case.
Unless stipulated by State or Territory legislation or adopted as traditional practice, floor wastes are only required under BCA Volume 1 in apartment buildings, residential buildings such as boarding houses or motels and residential parts of commercial buildings, if the bathroom is located above a sole occupancy unit or public space. There is no requirement for houses.
The intent of this provision is to provide protection to those other buildings and areas outside the immediate building, potentially being separation occupancies, in the event of flooding.
Falls to floor wastes
It is important to note that although a floor waste is generally not required in a Class 1 building, if one is provided, the bathroom floor must be graded to that waste.
This is noted in AS 3740 which states “Where a floor waste is provided the floor shall be graded to the waste’”. BCA Volume 2 also notes this in its definition of a floor waste.
Ref No. NAT BCA 08-22
The above is intended to provide general information in summary form. The contents do not constitute specific advice and should not be relied upon as such. Formal specific advice should be sought by members with respect to particular matters before taking action. ABN 99 004 631 752