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 updates to the NZ Metal Roof and Wall Cladding Code of Practice were published on 1 November 2022.
In a major update, the Clause 15.5 – previously 'Insulated Panels' – has been revised and extended.
The main clause has been renamed 15.5 Warm Roofs, and it now includes sub-clauses dealing with 15.5.1 Insulated Panels, 15.5.2 Composite Systems and 15.5.3 Spray-On Systems.
Other notable updates include:
- Changed recommendations for 5.4.6 Asymmetrical Valleys.
- Changed recommendations for 15.4.7 Standing Seam Roofing Wind Loads to minimise wind noise.
- The performance requirements quoted from 5.1 NZBC: Clause E1 — Surface Water has been expanded to better reflect the intent of NZBC E1 — Surface Water.
- The 3.8B Altitudes for Snow Loading Design was renamed to remove ambiguity.
- Roofing products with adhered absorbent fleece were added to 10.10 Ventilation Pathways.
- 18.104.22.168 Standing Seam Flashing details added to 15.4 Standing Seam Cladding.
The rest of the updates consist of minor edits for grammar, clarity, and layout.For more detailed information, see 19.1 2022 – November.