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.
The following revisions 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.
19.1A Revision Detail - 2023 - March
| Category | Clause Number (at time of update) | Clause (As of current publication) | Details |
|---|---|---|---|
| 3 - Substantial change to recommendation | 5.3.7 | 5.4.7 Gutter Capacity Calculator | Gutter Capacity Calculator now supports calculation where gutter fall is greater than 1:100, and has an option for Secret Gutters (i.e. where a roof slopes towards a raking wall or barge). |
| 3 - Substantial change to recommendation | 7.1.1 | 7.1.1 Minimum Roof Cladding Pitch | Revised and renamed table 7.1.1A Minimum Pitch for Generic Metal Roofing. |
| 4 - Clause Inserted | 5.2 Roof Drainage Terminology | New clause to clarify COP usage of terminology pertaining to Roof Drainage. | |
| 4 - Clause Inserted | 5.3.2.1 Designing for Climate Change | Newly introduced clause, recommending NIWA's HIRDS-tool. | |
| 4 - Clause Inserted | 5.4.1.1 Bay Windows | New clause discussing drainage for Bay Windows. | |
| 4 - Clause Inserted | 5.4.1.2 Outbuildings | New clause to give guidance on roof drainage for outbuildings. | |
| 2 - Editing and rearrangement | 1 | 1 Introduction | Updated Revisions Message |
| 2 - Editing and rearrangement | 2.1 | 2.1 Definitions | Added definitions for Freeboard, Internal gutter, Hidden gutter, Secret gutter, and Raking Spouting. |
| 1 - Minor Errata | 3.5.2 | 3.5.2 Wind Load | Fixed broken link. |
| 2 - Editing and rearrangement | 5.3.5.1 | 5.4.5.1 Internal Gutter Design Features | Added clarifying text regarding scuppers. |
| 2 - Editing and rearrangement | 5.4.6 | 5.5.6 Asymmetrical Valleys | Included details drawing for installing a . |
| 2 - Editing and rearrangement | 8.3 | 8.3 Flashing Cover | Added clarification of rib cover to 8.3K Apron Flashing Cover — Trapezoidal. |
| 2 - Editing and rearrangement | 8.4.2 | 8.4.2 Barge And Verge | Added illustrations showing details for:8.4.2B Stepped Fascia Corrugate Under Barge; 8.4.2C Stepped Fascia Corrugate Over Barge; 8.4.2D Stepped Fascia Trapezoidal Under Barge; 8.4.2E Stepped Fascia Trapezoidal Over Barge; and 8.4.2F Tray Roofing-Wall Connection. |
| 2 - Editing and rearrangement | 8.4.4 | 8.4.4 Apron Flashings | Added illustration showing 8.4.4H Parapet Flashing, Chase Cut and 8.4.4I Parapet Flashing, Face Fixed. |
| 1 - Minor Errata | 14.16 | 14.16 Stop-ends | Minor edit for clarity. |
| 2 - Editing and rearrangement | 14.17 | 14.17 Turndowns (Drip Forming or Drip Edging) | Edited copy to provide guidance for difficult to turn down profiles, such as deep corrugated profiles. |
| 4 - Clause Inserted | 19.1 2023 – March | Revision and updates active 1 March 2023. |