The NZ Metal Roof and Wall Cladding Code of Practice is a comprehensive design & installation guide, and a recognised related document for Acceptable Solution E2/AS1 of the NZ Building Code.
The NZ Metal Roof and Wall Cladding Code of Practice (COP) is published by NZ Metal Roofing Manufacturers Inc. (MRM), to provide:
- acceptable trade practice for the fixing of metal roof and wall cladding and accessories.
- prescriptive detailing for designers and sets a benchmark for the standard of detailing and workmanship required over and above that required to comply with the NZBC.
The COP does not describe or dismiss alternative methods, which may need specific acceptance by the Building Consent Authorities.
It is published in accordance with current technology, materials, and building codes. The COP will be periodically updated to reflect changes in legislation and standards or improvements in technology and available materials.
The most current Code of Practice is available on the MRM website, www.metalroofing.org.nz/cop, as Code of Practice Online (MRM COP Version 3).
The most recent Update to the COP was on 1 September 2021.
Summary of Changes in this update:
- In an important update, the recommendation for freeboard for internal gutters on the 5.3.7 Gutter Capacity Calculator was changed to 30mm to align with E1/AS1 and E1/AS2.
- The recommendation for minimum suitable pitch for 9.1 Penetrations Minimum Pitch, has been amended to include modern proprietary profiles.
- New clauses with easy-to-use fastener pattern reference tables. The tables would cover most standard corrugated and trapezoidal cladding, for 3.18 G550 Steel Cladding Fastening Pattern Tables and 3.20 Aluminium Fastening Pattern Tables.
- Other new clauses were for 5.4.4 Intersecting Valleys and 14.8 Double Lapping.
- The drawing in 5.7 Downpipe Spreaders was replaced to give a clearer reflection of the downpipe design and using the online downpipe spreader capacity calculator.
The rest of this update consisted of fixing minor errors.
See 19.1 2021 – September for details.