Most waterproof membrane systems are currently outside the scope of any of the Ministry of Business, Innovation and Employment’s (MBIE, previously the Department of Building and Housing) Acceptable Solutions to the New Zealand Building Code, and can only be considered as an Alternative Solution for the purposes of any building consent application, with the exception of pre-formed rubber and EPDM membranes which are included within the Ministry's Acceptable Solutions.
As there are no Standards or accepted industry-wide documents in use in New Zealand, the WMAI are developing a suite of Codes for waterproofing membranes which will set the minimum WMAI-agreed benchmark requirements for an Alternative Solution.
These Codes will also set recommended training criteria and installation methodology for the industry.
Our purpose is to develop and promote a suite of Codes of Practice that cover the following types of membranes:
- RMB (Reinforced Modified Bitumen) formally known as Torch-on membrane 4th edition published March 2021
- Liquid-applied
- Self-adhesive
- Internal Wet Area Membranes 5th edition published July 2022
- Below Ground Tanking Membranes published January 2023
View publications available for purchase on our Publications page >
The suite of Codes will include the following applications for membranes:
- Internal or external
- Above or below ground
- Roofing or decking
- Trafficable or non-trafficable
We aim to set the benchmark for best industry practice in relation to waterproof membranes.
Development Methodology
The development methodology for all Codes developed by the WMAI is as follows:
- The Members creates a “wish list” for the scope of the proposed document
- A review of international documents and publications, manufacturers and suppliers’ literature, and the New Zealand Building Code is undertaken to refine the scope
- Draft text is written, based on the surveyed literature, the practical experience of the committee members and from industry knowledge
- An initial draft is reviewed by the Members, and edited accordingly
- A public consultation draft is released to targeted industry parties for their comments, including the Ministry of Business, Innovation and Employment (New Zealand), industry organizations, BCAs (Building Consent Authorities), applicators, designers, suppliers, building owners, and roofing consultants
- Each comment received from the reviewers is considered and discussed by the Development Committee, and where appropriate changes are made
- The pre-print draft is reviewed and signed off by all members of the WMAI
- The Code is made available for download from the WMAI website, members’ websites, plus printed in hardcopy.