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Disclaimer

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.

Scope

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 v23.12:Installation; Stop-Ends

14.16 Stop-ends 

Stop-ends are required at the upper end of all roofing sheets, on horizontal metal wall cladding and at the lower edge of penetrations

Stop-ends for trapezoidal profiles are of two types, i.e. 'dog-eared' or 'pull-up'.

Stop-ending tools should be in good condition so that they do not mark the coating. This is particularly important when using pre-painted material.

Stop ending can cause distortion of the pan adjacent to the turn-up, which can cause contact and mark the turndown of the cover flashing onto the pan of the cladding. This can be avoided by technique and experiment, often standing in the pan adjacent to the end being stopped will prevent the pan from becoming convex at this point. 

14.16A Dog-eared Stop-ends

A 'dog-eared' or full stopend is made by cutting the rib back to the height of the profile so the material can be dressed and “wrapped around” 90°. It is not possible to dog-ear stop-end many profiles because of the shape of their rib.

To create dog-eared stop-ends:

  • Slit all ribs to a length equivalent to their height.
  • Cut away the tops of the ribs at a slight upwards angle and remove.
  • Insert turn-up tool to full depth and turn up more than right angles.
  • Knock dog's ears flat on a stop-end tool as shown.
  • Ensure tray is lying flat
The rib height should be added to the sheet length when the material
is ordered to provide an allowance for a full stop-end.

14.16B Pull-up Stopends

A 'pull-up' stop-end is not cut back but pulled up to the maximum allowable height without tearing the metal. No extra material allowance is required for a 'pull-up' stop-end. 

14.16C Corrugate Stop-ends

Stop-ends for corrugate should be pulled up to the full height of the profile, and on low pitches at exposed sites, additional weathering may be provided by the use of filler blocks. See 8.8 Profile Closures.