Code of Practice v3.0 Online
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.
COP v3.0:introduction
View Whole Section for Introduction
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 March 2023.
Substantial changes to recommendations:
- 5.4.7 Gutter Capacity Calculator extended to include secret gutters, and gutter fall greater than 1:100.
- New clause 5.2A Roof Drainage Terminology as used in the COP.
- Opinion on small sheds and bay windows that do not require spouting.
- Reviewed table 7.1.1 Minimum Roof Cladding Pitch and added maximum run.
- Added design advice for scuppers in 5.4.5.1 Internal Gutter Design Features
- Added advice for minimising roof noise in 15.4.7 Standing Seam Roofing Wind Loads.
Editing and rearrangement:
- Freeboard for Internal Gutters has been increased to 30mm to align with COP calculator and E1/AS1
- 14.11A Minimum Overhang updated drawing. No change to recommendations.
- 14.17 Turndowns (Drip Forming or Drip Edging) reviewed copy to provide guidance for difficult-to-turn-down profiles, such as deep corrugated profiles.
- 2 Glossary added definitions for freeboard, internal gutters, hidden gutters, secret gutters, and raked spouting.
- Updated illustrations detailing
8.4.2C Stepped Fascia Corrugate Over Barge, 8.4.2B Stepped Fascia Corrugate Under Barge,8.4.2E Stepped Fascia Trapezoidal Over Barge, 8.4.2D Stepped Fascia Trapezoidal Under Barge, 8.4.4H Parapet Flashing, Chase Cut, 8.4.4I Parapet Flashing, Face Fixed, 8.4.2F Tray Roofing-Wall Connection and 5.5.6A Valley Baffle.
Other changes consisted of small fixes for clarity and grammar.
For more detailed information, see 19.1 2023 – March.