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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 v24.09:Revision-History; 2022-November

2022 – November

19.8 2022 – November

In a major update, effective 1 November 2022, 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 5.5.6 Asymmetrical Valleys.
Changed recommendations for 15.4.9 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 3.6.2.2B Altitudes for Snow Loading Design was renamed to remove ambiguity.
Roofing products with adhered absorbent fleece were added to 10.10 Ventilation Pathways.
15.4.11 Tray Roof Flashing details added to 15.4 Tray Roofing.

The rest of the updates consist of minor edits for clarity and layout.

19.8A Revision Detail - 2022 - November

Category	Clause Number (at time of update)	Clause (As of current publication)	Details
2 - Editing and rearrangement	1	1 Introduction	Updated Revisions Message
2 - Editing and rearrangement	3.8	3.6.2.2 Snow Loads	Table 3.6.2.2B Altitudes for Snow Loading Designn was renamed to remove ambiguity.
1 - Minor Errata	3.15	3.4 Profiles	Renamed Tray/Deck profiles to Standing Seam/Tray Profiles.
1 - Minor Errata	5.1	5.1 NZBC: Clause E1 — Surface Water	Expanded performance requirement in accordance with E1– Surface Water.
3 - Substantial change to recommendation	5.4.6	5.5.6 Asymmetrical Valleys	Changed recommendation in line with the most recent 5.5.7 Valley Capacity Calculator.
2 - Editing and rearrangement	10.1	10.10 Ventilation Pathways	Added fleece lined products.
1 - Minor Errata	12.1.1	12.1.1 Wind Noise	Added recommendation to reduce Underlay Flutter, by adding spray-on foam insulation.
2 - Editing and rearrangement	15.3.2	15.3.2 Valleys	Updated Reference to 5.5.7 Valley Capacity Calculator
2 - Editing and rearrangement	15.4.6	15.4.8 Tray Ventilation	Replaced 15.4.8A Standing Seam Ventilation with better quality image.
3 - Substantial change to recommendation	15.4.7	15.4.9 Standing Seam Roofing Wind Loads	Change in recommendation.
4 - Clause Inserted		15.4.11 Tray Roof Flashing	Newly created clause.
3 - Substantial change to recommendation	15.5	15.5 Warm Roofs	The main clause Insulated Panels have been renamed Warm Roofs. In addition to insulated panels, the clause also features composite roofs and spray-on systems.
2 - Editing and rearrangement	15.5.1	15.5.1.1 Insulated Panel Manufacturing	The clause Design under Insulated Panels has been comprehensively reviewed and edited. It is now called Insulated Panel manufacturing. The rest of the content is available in smaller sub-clauses throughout the new clause 15.5.1 Insulated Panels.
4 - Clause Inserted		15.5.1 Insulated Panels	Newly created clause for Insulated Panels.
4 - Clause Inserted		15.5.1.2 Insulated Panel Composition	Newly created clause.
4 - Clause Inserted		15.5.1.3 Insulated Panel Face Profiles	Newly created clause.
4 - Clause Inserted		15.5.1.6 Insulation Panel Insulation Values	Newly created clause.
4 - Clause Inserted		15.5.1.8 Natural Lighting for Insulated Panels	Newly created clause.
4 - Clause Inserted		15.5.1.11 Insulated Panels Fitness for Purpose	Newly created clause.
4 - Clause Inserted		15.5.1.12 Insulated Panel Installation	Newly created clause.
4 - Clause Inserted		15.5.1.13 Insulated Panel Installation Safety	Newly created clause.
4 - Clause Inserted		15.5.1.15 Insulated Panel Penetrations	Newly created clause.
4 - Clause Inserted		15.5.1.17 Insulated Panel End Laps	Newly created clause.
2 - Editing and rearrangement	15.5.2	15.5.1.4 Insulated Panel Face Materials	The clause has been comprehensively reviewed and edited.
4 - Clause Inserted		15.5.2 Composite Systems	Newly created clause.
4 - Clause Inserted		15.5.2.1 Composite Systems Composistion	Newly created clause.
4 - Clause Inserted		15.5.2.2 Composite System Installation	Newly created clause.
2 - Editing and rearrangement	15.5.3	15.5.1.5 Insulated Panel Core Materials	The clause has been comprehensively reviewed and edited.
4 - Clause Inserted		15.5.3 Spray-On Systems	Newly created clause.
4 - Clause Inserted		15.5.3.1 Ventilation of Spray-on Systems	Newly created clause.
2 - Editing and rearrangement	15.5.4	15.5.1.7 Insulation Panel Structure	This clause has been comprehensively reviewed and edited.
2 - Editing and rearrangement	15.5.4.1	15.5.1.14 Insulated Panels Supporting Structure	The clause has been comprehensively reviewed and renamed.
0 - Clause Removed	15.5.5	Thermal	Clause was removed during the revision of Insulated Panels.
0 - Clause Removed	15.5.5.1	Fire	Clause was removed during a revision of Insulated Panels.
2 - Editing and rearrangement	15.5.6	15.5.1.10 Insulated Panels and Internal Moisture	This clause has been comprehensively reviewed and renamed.
2 - Editing and rearrangement	15.5.7	15.5.1.9 Insulated Panel Acoustics	This clause has been comprehensively reviewed and edited.
3 - Substantial change to recommendation	15.5.8	15.5.1.16 Fixing Insulated Panels	This clause has been comprehensively revised and renamed.
2 - Editing and rearrangement	15.5.9	15.5.1.18 Insulated Panel Flashings	This clause has been comprehensively revised and renamed.
2 - Editing and rearrangement	17.3	17.3 MRM Soft Edge Standard	Editing for clarity.
4 - Clause Inserted		19.8 2022 – November	Revision summary for the November 2022 update.