AS 3740:2021 Waterproofing of domestic wet areas
Supersedes: AS 3740-2010 Waterproofing of domestic wet areas
This document sets out minimum requirements for the materials, design and installation of waterproofing for domestic wet areas. This document applies to internal wet areas as defined in the National Construction Code (NCC).
NOTE 1: Appendix A provides design considerations for categories of wet area waterproofing.
The following are excluded from the scope of this document:
(a) Situations where flooding of the wet areas occurs through overflowing of vessels or plumbing failures.
(b) Concrete admixtures or penetrant sealers or similar.
(c) Decorative coatings.
(d) Communal or group wet areas such as shower areas as in swimming pool complexes, sporting
facilities, steam rooms, and similar situations.
NOTE 2: A suggested checklist of items to be reviewed following installation of waterproofing is provided in Appendix D.
NOTE 3: A method to determine whether the subfloor moisture content is suitable for the installation of waterproof membranes is provided in Appendix F.
The objective of this document is to set out the criteria for waterproofing wet areas within domestic buildings. It gives minimum requirements for materials, designs and installations.
The objective of this revision is to bring this document in line with the current waterproofing practices in the building industry. Changes from the previous edition include the following:
(a) Restructure for usability.
(b) Addition of figures with examples of application.
(c) Addition of information on risk levels of different areas.
(d) Inclusion of appropriate details for various risk levels.
(e) Clarification of usage definitions.
(f) Increased ease of reference for varying conditions.
(g) Revision of design and installation techniques.
(h) Expansion of information on shower and bath scenarios.
(i) Inclusion of informative integrity testing.
The role of waterproofing is to install waterproofing systems as a combination of waterproof and water-resistant materials in order to retain water within the designated wet area and exclude water from non-water-resistant building elements. It is intended that water be managed to an outfall at surface and substrate. Systems are intended to accommodate expected service conditions of the wet area to prevent damage by water and accumulated moisture to building elements.
This document is not to be interpreted as preventing the use of materials, systems or methods that meet the design and installation criteria set out in this document, but are not specifically referred to herein (alternative solution).
Additional requirements may need to be considered for wet areas intended for use by people with disabilities.
Wet Areas in Buildings.
Association of Wall and Ceiling Industries of Australia; Australasian Concrete Repair and Remedial Building Association; Australian Building Codes Board; Australian Industry Group; Australian Institute of Building Surveyors; Australian Institute of Waterproofing; Australian Tile Council; Better Regulation Division; CSIRO; Engineered Wood Products Association of Australasia; Housing Industry Association; Institute of Building Consultants.