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 23.09).
The following revisions to the NZ Metal Roof and Wall Cladding Code of Practice were published on 1 September 2023.
Versioning and presentation:
- Beginning with this revision the Code of Practice updates its version number with each update, to make it clear when the current update was published.
The version numbering uses a year.month pattern: for example this update is v23.09, where 23 indicates the year (2023) and 09 indicates the month (September).
Refer to 19 Revision History for a log of specific changes in each update.
- An overall upgrade to styling for improved typeface readability and better contrast in headings.
- Additionally there are new "Quick Actions" on the COP Home page for reference to updates and interactive tools, and the registration process has been streamlined.
Substantial change to recommendations:
- 16 Maintenance and all its sub-clauses have been comprehensively revised.
- 5.6.2 Sumps: Added recommendation to seal internal sumps against the sides and soles of the gutter.
- 14.19.3 Correctly Installed Gutters: Changed recommendation for gutter drainage to be more consistent with MBIE tolerances.
- In 3 Structure, tables and graphs have been rearranged to correspond to whether the design is under NZS3604 or AS/NZS1170:
3.10 Fastening Pattern Tables – Designs to NZS 3604
3.11 Wind Load/Span Graphs – Designs to AS/NZS1170
The rest of the updates consisted of minor corrections and edits.For more detailed information, see 19.1 2023 – September.