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Although the information contained in this Code has been obtained from sources believed to be reliable, New Zealand Metal Roofing Manufacturers Inc. makes no warranties or representations of any kind (express or implied) regarding the accuracy, adequacy, currency or completeness of the information, or that it is suitable for the intended use.

Compliance with this Code does not guarantee immunity from breach of any statutory requirements, the New Zealand Building Code or relevant Standards. The final responsibility for the correct design and specification rests with the designer and for its satisfactory execution with the contractor.

While most data have been compiled from case histories, trade experience and testing, small changes in the environment can produce marked differences in performance. The decision to use a particular material, and in what manner, is made at your own risk. The use of a particular material and method may, therefore, need to be modified to its intended end use and environment.

New Zealand Metal Roofing Manufacturers Inc., its directors, officers or employees shall not be responsible for any direct, indirect or special loss or damage arising from, as a consequence of, use of or reliance upon any information contained in this Code.

New Zealand Metal Roofing Manufacturers Inc. expressly disclaims any liability which is based on or arises out of the information or any errors, omissions or misstatements.

If reprinted, reproduced or used in any form, the New Zealand Metal Roofing Manufacturers Inc. (NZMRM) should be acknowledged as the source of information.

You should always refer to the current online Code of Practicefor the most recent updates on information contained in this Code.


This Code of Practice provides requirements, information and guidelines, to the Building Consent Authorities, the Building Certifier, Specifier, Designer, Licensed Building Practitioner, Trade Trainee, Installer and the end user on the design, installation, performance, and transportation of all metal roof and wall cladding used in New Zealand.

The calculations and the details contained in this Code of Practice provide a means of complying with the performance provisions of the NZBC and the requirements of the Health and Safety at Work Act 2015.

The scope of this document includes all buildings covered by NZS 3604, AS/NZS 1170 and those designed and built under specific engineering design.

It has been written and compiled from proven performance and cites a standard of acceptable practice agreed between manufacturers and roofing contractors.

The drawings and requirements contained in this Code illustrate acceptable trade practice, but recommended or better trade practice is also quoted as being a preferred alternative.

Because the environment and wind categories vary throughout New Zealand, acceptable trade practice must be altered accordingly; in severe environments and high wind design load categories, the requirements of the NZBC will only be met by using specific detailing as described in this Code.

The purpose of this Code of Practice is to present both Acceptable Trade Practice and Recommended Trade Practice, in a user-friendly format to ensure that the roof and wall cladding, flashings, drainage accessories, and fastenings will:

  • comply with the requirements of B1, B2, E1 E2 and E3 of the NZBC;
  • comply with the design loading requirements of AS/NZS 1170 and NZS 3604 and with AS/NZS 1562;
  • have and optimised lifespan; and
  • be weathertight.

COP v24.03:Safety; Responsibilities

13.2 Responsibilities 

The HSWA identifies four duty holders responsible for health and safety on site.
They are;
  • PCBU's
  • Officers,
  • Workers, and
  • Other People.

13.2.1 PCBU 

The person conducting a business or undertaking (PCBU) is not necessarily one person. It is a business entity in most cases, but there could be more than one PCBU involved with a project; clients, principal contractors, and sub-contractors can all be PCBUs.

The ‘Primary duty of care’ of the PCBU is to ensure the health and safety of workers and anyone else who might be affected by the work done. PCBU Responsibilities 

The PCBU must (as far as reasonably practicable):

  • Provide and maintain a workplace that is without risks to health and safety.
  • Ensure the safe use, handling, and storage of plant, structures, and substances.
  • Provide adequate facilities for the welfare of workers.
  • Provide the information, training, instruction, or supervision that is necessary to protect all persons from risks to their health and safety arising from work.
  • Monitor the health of workers and the conditions at the workplace to prevent injury or illness.

13.2.2 Officers 

Officers are people (including chief executive officers and directors) who have significant influence over the management of a business. An advisor is not considered an officer.

Sole traders have the responsibilities of both a PCBU and an officer. Officer Responsibilities 

An officer must take reasonable steps to:

  • Keep up to date about work health and safety matters.
  • Understand the nature of the hazards and risks associated with the organisation's operations.
  • Ensure the organisation has resources and processes in place to eliminate or minimise risks.
  • Ensure appropriate and timely processes are in place for receiving and responding to incidents, hazards, and risks.
  • Ensure there are processes for complying with any duty.
  • Verify that health and safety processes are in place and being used.

13.2.3 Workers 

A worker is anybody who carries out work on behalf of a PCBU. Workers' Responsibilities 

Workers must:

  • Take reasonable care to ensure the health and safety of themselves and others in the workplace.
  • Comply with health and safety policies and procedures of the PCBU.

Workers have the right to refuse to undertake unsafe or dangerous work.

13.2.4 Other People 

Other people in the workplace includes visitors and customers. Other People's Responsibilities 

Other People must:

  • Take reasonable care for their own health and safety.
  • Ensure that their acts or omissions do not adversely affect the health and safety of others.
  • Comply with safety instructions and procedures issued by the PCBU.