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,, as Code of Practice Online (MRM COP Version 3).

The most recent Update to the COP was on 1 December 2019.

Major Revisions

  1. For this update, the COP section 5 Roof Drainage and all its sub-clauses have been substantially revised. The updates focussed heavily on creating new online tools for calculating Roof Drainage, Gutter Capacity, Downpipe Capacity and Valley Capacity, which are located in 5.7 Capacity Calculations.

Summary of other changes in this update

See 19.1 2019 – December for details of the changes in this Update.