CODE OF PRACTICE NZ METAL ROOF AND WALL CLADDING VERSION 2.2 / 2012
NZ METAL ROOF AND WALL CLADDING CODE OF PRACTICE
Apr 05, 2023
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VERSION 2.2 / 2012
N Z M E T A L R O O F A N D W A L L C L A D D I N G C O D E O F P R A C T I C E
© N E W Z E A L A N D M E T A L R O O F I N G M A N U F A C T U R E R S I N C . A P R I L 2 0 1 2
PREFACE
PREFACE
This NZ Metal Roof and Wall Cladding Code of Practice is published by the NZ Metal Roofing Manufacturers Inc., to provide prescriptive acceptable trade practice for the fixing of metal roof and wall cladding and accessories. In addition it provides prescriptive detailing for designers and sets a benchmark for the standard of detailing and workmanship required over and above that required deemed to comply with the NZBC. This does not pre-empt or preclude the use of alternative methods that would also require specific acceptance by the Building Consent Authorities.
This Industry Code of Practice is published as the current state of the art at publication date, however it is recognised that as building is a dynamic industry the Code is a living document, and that alterations to legislation, standards, improved technology and new materials will require periodic upgrading of this Code of Practice.
Version 2.2 of the NZMRM Code of Practice as published at November 2012 supersedes the original versions published in 2008 and 2003.
Updates of Version 2 are now available as Version 2.2 in a pdf format which can be downloaded from the MRM website. http://metalroofing.org.nz . Version 2.2 is also available to be used on the website with options to print, email and search topics. The illustrations in the Code of Practice can be downloaded from the website as eps. or jpeg files. The Code of Practice is protected by copyright however the drawings and text are available to be copied and printed provided a signed license agreement is completed with the NZMRM and acknowledgment is given.
The pdf and website documents of the Code of Practice Version 2.2 are structured to mirror each other page for page so that any reference from one document can quickly be identified in the other by page number or section number.
A red line and date has been included to indicate where Version 2 has been updated to Version 2.2.
References to ‘consult or refer to the Manufacturer’ or ‘in accordance with standard trade practice’ have been omitted. This Code of Practice has been prepared after general consensus has been obtained between suppliers, manufacturers, and members of the Roofing Association of New Zealand (RANZ).
The Code is divided into three parts:
1. The performance requirements, and the prescriptive means to comply with this Code of Practice are printed in black bold font and blue shaded. They are summarised in Section 17 the Appendix.
The ‘What’ and the ‘How’.
The first part is normative, i.e. compliance is mandatory to comply with this Code of Practice and the word ‘must’ is used.
2. The recommended better practice options and the responsibilities of different parties to comply are printed in black - the ‘Should know’ and ‘should do’s’.
The second part is not mandatory but describes better options or alternatives. They are described by the words ‘should’, ‘recommend’, ’preferred’ and ‘may’.
3. The reasoning used to formulate the above is printed in blue - the ‘Why’.
The third part is informative, i.e. it is for information and reference.
The provision of the third part is intended to provide the education necessary to inform designers, to complement and complete the training required to qualify as a Licenced Building Practitioner or skilled tradesperson and also to be used as a text book in such training. The Code of Practice is intended to be a stand-alone document, however users are urged to read manufacturers literature and other relevant documentation that should be used in conjunction with this Code of Practice. Although it is written in user friendly terminology some words may not be in common usage however definitions and alternative words are found in section 1.3.
N Z M E T A L R O O F A N D W A L L C L A D D I N G C O D E O F P R A C T I C E
© N E W Z E A L A N D M E T A L R O O F I N G M A N U F A C T U R E R S I N C . A P R I L 2 0 1 2
PREFACE
V:2.2 PREFACE
Users are urged to read the complete document, as the reasoning and commentary provide a means of compliance with details and situations that may have not been previously encountered. Because metal roof and wall cladding is now regarded as a system and not a product, the interaction with, and the dependence on, other materials requires an understanding of the total Building Envelope. The implications of some subjects, such as condensation and loadings, are not always understood by designers, and therefore the roofing contractor has a responsibility to draw attention to any inadequate or incorrect detailing. No apology is offered for the complexity or any repetition included in this Code of Practice. Cross- referencing has been necessary to avoid duplication, but is available electronically by hyperlink throughout the Code, via the contents, the description, drawing details or ‘find’ or ‘search’.
Specifiers, manufacturers, tradespeople and the public should be aware of the limitations of the material they are using, because without full understanding users can be held liable for lack of ‘duty of care’. This document should be regarded as the ‘state of the art’ at the time of publication, however it is incumbent on all practitioners to ensure that any documentation used is the current version published by the NZMRM Inc.
This Code of Practice has been written to assist in meeting the requirements of the NZBC. partly because of the many conflicting and overlapping Standards used within the Building Industry. A current NZ, joint NZS/AS Standard or a Producer Statement can be cited as a means of specific compliance acceptable to a Building Consent Authority but which does not coincide with this Code of Practice. The information and evidence offered in support of the requirements of this Code has been obtained after wide consultation with associated industry participants resulting in a general consensus, acceptance and approval of those concerned.
The New Zealand Roof and Wall Cladding Code of Practice has been written for New Zealand conditions that recognize it as an unique island 2,000 km away from another major land mass, which is subject to high rainfall, high humidity, extremes of weather and high winds. The contents of this Code of Practice are relevant to other countries, but the information contained in this document should be moderated appropriately in accordance with local conditions. Overseas Standards and Codes of Practice are not always relevant to N.Z. conditions and should not be used in preference to this N.Z. Code of Practice.
© N E W Z E A L A N D M E T A L R O O F I N G M A N U F A C T U R E R S I N C . A P R I L 2 0 1 2
TABLE OF CONTENTSN Z M E T A L R O O F A N D W A L L C L A D D I N G C O D E O F P R A C T I C E
V:2.2 PAGE 3
2 .0 PERFORMANCE
10.0 PRESSED METAL TILES
12.0 INSULATED PANELS
17.0 USEFUL INFORMATION
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1.1. Disclaimer and copyright 1.2. Scope 1.3. Definitions 1.4. Descriptions
1.4.1. Domestic drawing details 1.4.2. Industrial drawing details 1.4.3. Product geometry
1.5. Acknowledgments 1.6. Related documents 1.7. Disputes
1.7.1. Mediation 1.7.2. Adjudication 1.7.3. Arbitration and litigation
2 .0 PERFORMANCE
2.1. NZBC 2.1.1. Durability
2.2. Metals 2.2.1. Thickness 2.2.2. Strength 2.2.3. Metallic coatings 2.2.4. Galvanised steel 2.2.5. AZ coatings 2.2.6. ZA coatings 2.2.7. Organic coatings 2.2.8. Powder coating 2.2.9. Aluminium 2.2.10. Stainless steel 2.2.11. Copper 2.2.12. Lead 2.2.13. Zinc
2.3. Sacrificial protection 2.3.1. Cut edges 2.3.2. Passivity 2.3.3. Microcracking 2.3.4. Minimum radius 2.3.5. Oil-canning 2.3.6. Material 2.3.7. Installation 2.3.8. Distortion
2.4. Metal corrosion 2.4.1. Types of corrosion 2.4.2. Metal performance 2.4.3. The atmosphere 2.4.4. The rain 2.4.5. Pollutants 2.4.6. Atmospheric corrosion 2.4.7. Galvanic corrosion 2.4.8. The electrochemical or galvanic series 2.4.9. Galvanic table
2.5. Environment 2.5.1. Environmental categories 2.5.2. Special environments
2.6. Types of corrosion 2.6.1. Crevice corrosion 2.6.2. Pitting corrosion 2.6.3. Poultice corrosion 2.6.4. Inert catchment 2.6.5. Ponding 2.6.6. Capillary 2.6.7. Unwashed areas 2.6.8. Corrosion rate 2.6.9. Solar collectors
2.7. Compatibility 2.7.1. Dissimilar materials 2.7.2. Compatibility table 2.7.3. Runoff corrosion 2.7.4. Fall-out corrosion
2.8. Organic coating protection 2.8.1. Underside protection 2.8.2. Colour differential 2.8.3. Touch up 2.8.4. Lap priming 2.8.5. Strippable films
2.9. Fatigue
3 .0 LOADINGS
3.0.1. AS/NZS 1170: 2002 3.0.2. NZS 3604: 1999 3.0.3. Types of load
3.1. Performance under load 3.1.1. Deflection 3.1.2. Section properties 3.1.3. Continuity
3.2. Point load
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3.3. Wind load. (U.D.L.) 3.3.1. Pressure coefficients 3.3.2. Local pressure coefficients kl
3.4. Load calculation 3.4.1. Wind load calculation
3.5. Snow loads 3.6. Fastener withdrawal loads
3.6.1. Timber purlins 3.6.2. Steel purlins 3.6.3. Steel battens
3.7. Super imposed and construction loads 3.8. Testing 3.9. Wind load span graphs
3.9.1. Profile shape 3.9.2. Trapezoidal profiles 3.9.3. Miniature profiles 3.9.4. Purlin overhang
4 .0 . DESIGN
4.1. Heat 4.1.1. Conduction 4.1.2. Radiation 4.1.3. Convection 4.1.4. Thermal expansion and contraction 4.1.5. Temperature range 4.1.6. Roof cladding expansion provisions 4.1.7. Profile strength 4.1.8. End laps 4.1.9. Roof noise
4.2. Condensation 4.2.1 Clause E3 internal moisture 4.2.2. Condensation 4.2.3. Water vapour 4.2.4. Night sky radiation
4.3. Underlay 4.3.1. Types of underlay 4.3.2. Use of underlays and vapour barriers 4.3.3. Synthetic wraps 4.3.4. Cold roof construction 4.3.5. Warm roof construction 4.3.6. Durability 4.3.7. Passive ventilation 4.3.8. horizontal laying 4.3.9 Vertical laying 4.3.10. Underlay and vapour barrier support 4.3.11. Seperation
4.4. Vapour barriers 4.4.1. Types of vapour control layer 4.4.2. Special requirements
4.5. Cavity construction 4.5.1. Types of cavities 4.5.2. Roof cavities 4.5.3. Wall cavities 4.5.4. Vertical cladding 4.5.5. Ventilation 4.5.6. Drainage path 4.5.7. Cavity underlays 4.5.8. Battens 4.5.9. Fasteners
4.6. Ventilation 4.6.1. Intake vents 4.6.2. Exhaust vents 4.6.3. Mechanical vents
4.7. Insulation 4.7.1. Types of insulation 4.7.2. Insulation position 4.7.3. Counterbattens
4.8. Roof pitch 4.8.1. Minimum roof cladding pitch 4.8.2. Runoff 4.8.3. Snow 4.8.4. hail
4.9. Curved roofs 4.9.1. Spring curving 4.9.2. Laps 4.9.3. Transverse laps 4.9.4. Durability 4.9.5. Purlin spacing 4.9.6. Concave roofs 4.9.7. Pre-curved roofs 4.9.8. Roll curving 4.9.9. Crimp curving
5 .0 FLAShINGS
5.2. Flashing cover 5.2.1. Flashing laps 5.2.2. Flashing edges
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1 TABLE OF CONTENTS
5.3. Flashing types 5.3.1. Ridge, and hip 5.3.2. Ridge - hip intersections 5.3.3. Barge and verge 5.3.3.1. Internal barge flashing 5.3.4. Parapet cappings 5.3.5. Apron flashings 5.3.5.1. Apron and parapet capping
terminations 5.3.5.2. Change of pitch 5.3.5.3. Step apron 5.3.5.4. Gutter apron 5.3.6 Valley 5.3.7. Soffit flashings 5.3.8. Flashings for vertical cladding 5.3.9. Flashings for horizontal corrugate
5.4. Fastening 5.4.1. Primary fasteners 5.4.2. Secondary fasteners 5.4.3. Secret fixing clips 5.4.4. Cleats 5.4.5. Seams 5.4.6. Flashing expansion 5.4.7. Expansion details 5.4.8. Building expansion joints
5.5. Curved flashings 5.5.1. Lockseamed flashings 5.5.2. Jennied flashings 5.5.3. Crimped flashings
5.6. Sealants 5.6.1. Properties 5.6.2. Methods of sealing 5.6.3. Surface preparation 5.6.4. Sealant extrusion and placement 5.6.4.1. Sealed laps 5.6.5. Strip sealants 5.6.6. Soldered joints
5.7. Profile closures 5.7.1. Vented fillers 5.7.2. Metal closures
5.8. Ridge vents 5.8.1. Ventilating ridging
6 .0 PENETRATIONS
6.1.1. Responsibility 6.1.2. Durability 6.1.3. Corrosion 6.1.4. Catchment 6.1.5. Obstruction 6.1.6. Discharge capacity 6.1.7. Sealing 6.1.8. Alternative materials
6.2. Penetration design 6.2.1. Nomenclature 6.2.2. Diverter and cricket designs 6.2.3. Installation 6.2.4. Laps 6.2.5 Details 6.2.6. Types of penetration flashing design 6.2.7. Type A soaker 6.2.8. Type B watershed 6.2.9. Type C tapered 6.2.10. Type D tray
6.3. Collar or boot flashings 6.3.1. Plant room and conduit penetrations
6.4. Window flashings for metal cladding 6.4.1 Flush window flashings 6.4.2. Recessed window flashings 6.4.3. Butt window flashings 6.4.4. Flashings for vertical cladding 6.4.5. Alternative flashing designs
6.5. Dormer junctions
7 .0 INSTALLATION
7.1. Pre-installation 7.1.1. Setting out and laying 7.1.2 Downturns 7.1.3. Stopends 7.1.4. Overhang 7.1.5 Cutting and drilling
7.2. Swarf 7.2.1. Swarf removal 7.2.2. Swarf damage
7.3. Fasteners 7.3.1. Primary fasteners 7.3.2. Nails 7.3.3. Screws
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7.4. Secondary fasteners 7.4.1 Rivets 7.4.2 Monel rivets 7.4.3 Aluminium rivets 7.4.4 Stainless steel rivets 7.4.5 Spacing 7.4.6. Fastener frequency
7.5. Fixing 7.5.1 Crest fixing 7.5.2. Pan fixing 7.5.3. Expansion fixings 7.5.4. Lap stitching
7.6. Installation 7.6.1. Driving 7.6.2. Tools 7.6.3. Modes of failure
7.7. Fastener loads 7.7.1. Load spreading washers 7.7.2. Sealing washers
7.8. Performance 7.8.1 Pull-out values 7.8.2 Pull-over values 7.8.3. Fastener durability 7.8.4. Corrosion 7.8.5. Coating thickness 7.8.6 Compatibility of fasteners 7.8.7. Purlin creasing
7.9. Fastening patterns 7.10. Reroofing 7.11 Fixing Aluminium Sheeting
8 .0 ROOF DRAINAGE
8.2.1. Catchment area 8.2.2. Capacity calculations 8.2.3. Profile capacity
8.3. Snow 8.3.1. hail
8.4. Gutters 8.4.1. Gutter installation 8.4.2. Gutter support systems 8.4.3. Eaves gutters 8.4.4. Internal gutters 8.4.5. Valley gutters 8.4.6. Fascia gutters
8.4.7 Concealed gutter systems 8.4.8. Secret gutters 8.4.9 Fall
8.5. Downpipes 8.5.1. Downpipe spreaders
8.6. Sumps 8.6.1. Rainwater heads 8.6.2. Outlets and overflows
9 .0 PLASTIC ROOFLIGhTING
9.2.1. Glass reinforced plastic. GRP 9.2.2. Polycarbonate 9.2.3. UPVC
9.3. Types of roof lights 9.4. Light transmission 9.5. Weathering and durability 9.6. Loadings
9.6.1. Point load. Walking traffic 9.6.2. U.D.L. wind and snow loads
9.7. Fixing 9.7.1. Side-lap fixing 9.7.2. Side-lap fixing between purlins 9.7.3. End laps 9.7.4. Span-breakers 9.7.5. Stopends 9.7.6. Purlin protection 9.7.7. Drainage 9.7.8. Condensation 9.7.9. Pitch
9.8. Thermal expansion 9.9. Transport, handling and storage
9.9.1. Maintenance
10.1. Design 10.1.1. Durability 10.1.2. Pitch 10.1.3. Underlays 10.1.4 Roof framing 10.1.5. Tiling battens
10.2. Roof drainage 10.2.1. Valleys 10.2.2. Valley installation
10.3. Flashings 10.3.1. Ridge
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1 TABLE OF CONTENTS
10.3.2. Gable ends 10.3.3. hip 10.3.4. Vertical wall 10.3.5 Wall to roof junctions 10.3.6. Penetrations
10.4. Installation 10.4.1. Laying 10.4.2. Roof traffic 10.4.3. Workmanship
10.5. Sitework
11.0 SECRET F IxED CLADDING
11.1. Self supporting cladding 11.2. Fully supported roof and wall cladding
11.2.1. Types 11.2.2. Traditional architectural metal
panels 11.2.3. Long length strip roof cladding 11.2.4. Types of joints 11.2.5. Standing seam 11.2.6. Angle seam 11.2.7. Roll cap 11.2.8. Transverse laps
11.3 Materials 11.3.1. Copper 11.3.2. Zinc 11.3.3. Aluminium 11.3.4. Stainless steel 11.3.5. Coated steel
11.4. Loadings 11.4.1 Fixing 11.4.2. Substrate 11.4.3. Clips, cleats and fasteners
11.5. Underlay 11.5.1. Ventilation
11.7. Façade cladding 11.8. Edge finishes
11.8.1. Ridge and hip 11.8.2. Apron or abutment 11.8.3. Eaves and verge 11.8.4. Penetrations 11.8.5. Cappings
11.9. Durability
12.0 INSULATED PANELS
12.4.1. Supporting structure 12.5. Thermal
12.5.1. Fire 12.6. Condensation 12.7. Acoustic 12.8. Fixing 12.9. Flashings
13.0 MAINTENANCE
13.5.1. Installation 13.6. Washing
13.7. Overpainting 13.7.1. Unpainted cladding 13.7.2 Repainting painted claddings 13.7.3. Weathered with white corrosion 13.7.4. Red corrosion 13.7.5. Paint 13.7.6. Brush application 13.7.7. Roller application 13.7.8. Spray application
13.8. Material selection 13.8.1. Residential 13.8.2. Commercial 13.8.3. Responsibility & liability 13.8.4. Special environments and exclusions:
13.9. Drinking water
14.0 SITE PRACTICE
14.1. Safety 14.1.1. Responsibilities 14.1.2. Training
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14.1.3. Working at height 14.1.3.1. Roof edge protection 14.1.4. Residential and light commercial
roofing 14.1.5. Limitations of fall arrest and
travel restraint 14.1.6. Access 14.1.7. Scaffolding 14.1.8. Mobile scaffolds 14.1.9. Personal safety 14.1.10. Safety mesh 14.1.11. Timber fixing 14.1.12. Steel fixing
14.2. Transportation 14.3. Handling 14.4. Acceptance of materials
14.4.1. Presence of moisture between sheets 14.4.2. Colour match 14.4.3. Storage 14.4.4. Storage stain
14.5. Roof loading 14.6. Walking on roofs
14.6.1. Roof access during construction 14.6.2. Roof cladding damage
14.7. Completion 14.8. Tools of the trade
15.0 TESTING
15.1. Scope 15.2. Commentary on part 15.1 15.3. General methods of testing sheet roof and wall cladding 15.4. Commentary on part 15.3 15.5. Specific methods of testing sheet roof and wall cladding for point load 15.6. Commentary on part 15.5 15.7. Specific methods of testing sheet roof and wall cladding to determine their resistance to wind pressures (UDL - uniformly distributed load)
16.0 LIST OF MEMBERS OF ThE NZ METAL…
N Z M E T A L R O O F A N D W A L L C L A D D I N G C O D E O F P R A C T I C E
© N E W Z E A L A N D M E T A L R O O F I N G M A N U F A C T U R E R S I N C . A P R I L 2 0 1 2
PREFACE
PREFACE
This NZ Metal Roof and Wall Cladding Code of Practice is published by the NZ Metal Roofing Manufacturers Inc., to provide prescriptive acceptable trade practice for the fixing of metal roof and wall cladding and accessories. In addition it provides prescriptive detailing for designers and sets a benchmark for the standard of detailing and workmanship required over and above that required deemed to comply with the NZBC. This does not pre-empt or preclude the use of alternative methods that would also require specific acceptance by the Building Consent Authorities.
This Industry Code of Practice is published as the current state of the art at publication date, however it is recognised that as building is a dynamic industry the Code is a living document, and that alterations to legislation, standards, improved technology and new materials will require periodic upgrading of this Code of Practice.
Version 2.2 of the NZMRM Code of Practice as published at November 2012 supersedes the original versions published in 2008 and 2003.
Updates of Version 2 are now available as Version 2.2 in a pdf format which can be downloaded from the MRM website. http://metalroofing.org.nz . Version 2.2 is also available to be used on the website with options to print, email and search topics. The illustrations in the Code of Practice can be downloaded from the website as eps. or jpeg files. The Code of Practice is protected by copyright however the drawings and text are available to be copied and printed provided a signed license agreement is completed with the NZMRM and acknowledgment is given.
The pdf and website documents of the Code of Practice Version 2.2 are structured to mirror each other page for page so that any reference from one document can quickly be identified in the other by page number or section number.
A red line and date has been included to indicate where Version 2 has been updated to Version 2.2.
References to ‘consult or refer to the Manufacturer’ or ‘in accordance with standard trade practice’ have been omitted. This Code of Practice has been prepared after general consensus has been obtained between suppliers, manufacturers, and members of the Roofing Association of New Zealand (RANZ).
The Code is divided into three parts:
1. The performance requirements, and the prescriptive means to comply with this Code of Practice are printed in black bold font and blue shaded. They are summarised in Section 17 the Appendix.
The ‘What’ and the ‘How’.
The first part is normative, i.e. compliance is mandatory to comply with this Code of Practice and the word ‘must’ is used.
2. The recommended better practice options and the responsibilities of different parties to comply are printed in black - the ‘Should know’ and ‘should do’s’.
The second part is not mandatory but describes better options or alternatives. They are described by the words ‘should’, ‘recommend’, ’preferred’ and ‘may’.
3. The reasoning used to formulate the above is printed in blue - the ‘Why’.
The third part is informative, i.e. it is for information and reference.
The provision of the third part is intended to provide the education necessary to inform designers, to complement and complete the training required to qualify as a Licenced Building Practitioner or skilled tradesperson and also to be used as a text book in such training. The Code of Practice is intended to be a stand-alone document, however users are urged to read manufacturers literature and other relevant documentation that should be used in conjunction with this Code of Practice. Although it is written in user friendly terminology some words may not be in common usage however definitions and alternative words are found in section 1.3.
N Z M E T A L R O O F A N D W A L L C L A D D I N G C O D E O F P R A C T I C E
© N E W Z E A L A N D M E T A L R O O F I N G M A N U F A C T U R E R S I N C . A P R I L 2 0 1 2
PREFACE
V:2.2 PREFACE
Users are urged to read the complete document, as the reasoning and commentary provide a means of compliance with details and situations that may have not been previously encountered. Because metal roof and wall cladding is now regarded as a system and not a product, the interaction with, and the dependence on, other materials requires an understanding of the total Building Envelope. The implications of some subjects, such as condensation and loadings, are not always understood by designers, and therefore the roofing contractor has a responsibility to draw attention to any inadequate or incorrect detailing. No apology is offered for the complexity or any repetition included in this Code of Practice. Cross- referencing has been necessary to avoid duplication, but is available electronically by hyperlink throughout the Code, via the contents, the description, drawing details or ‘find’ or ‘search’.
Specifiers, manufacturers, tradespeople and the public should be aware of the limitations of the material they are using, because without full understanding users can be held liable for lack of ‘duty of care’. This document should be regarded as the ‘state of the art’ at the time of publication, however it is incumbent on all practitioners to ensure that any documentation used is the current version published by the NZMRM Inc.
This Code of Practice has been written to assist in meeting the requirements of the NZBC. partly because of the many conflicting and overlapping Standards used within the Building Industry. A current NZ, joint NZS/AS Standard or a Producer Statement can be cited as a means of specific compliance acceptable to a Building Consent Authority but which does not coincide with this Code of Practice. The information and evidence offered in support of the requirements of this Code has been obtained after wide consultation with associated industry participants resulting in a general consensus, acceptance and approval of those concerned.
The New Zealand Roof and Wall Cladding Code of Practice has been written for New Zealand conditions that recognize it as an unique island 2,000 km away from another major land mass, which is subject to high rainfall, high humidity, extremes of weather and high winds. The contents of this Code of Practice are relevant to other countries, but the information contained in this document should be moderated appropriately in accordance with local conditions. Overseas Standards and Codes of Practice are not always relevant to N.Z. conditions and should not be used in preference to this N.Z. Code of Practice.
© N E W Z E A L A N D M E T A L R O O F I N G M A N U F A C T U R E R S I N C . A P R I L 2 0 1 2
TABLE OF CONTENTSN Z M E T A L R O O F A N D W A L L C L A D D I N G C O D E O F P R A C T I C E
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2 .0 PERFORMANCE
10.0 PRESSED METAL TILES
12.0 INSULATED PANELS
17.0 USEFUL INFORMATION
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1.1. Disclaimer and copyright 1.2. Scope 1.3. Definitions 1.4. Descriptions
1.4.1. Domestic drawing details 1.4.2. Industrial drawing details 1.4.3. Product geometry
1.5. Acknowledgments 1.6. Related documents 1.7. Disputes
1.7.1. Mediation 1.7.2. Adjudication 1.7.3. Arbitration and litigation
2 .0 PERFORMANCE
2.1. NZBC 2.1.1. Durability
2.2. Metals 2.2.1. Thickness 2.2.2. Strength 2.2.3. Metallic coatings 2.2.4. Galvanised steel 2.2.5. AZ coatings 2.2.6. ZA coatings 2.2.7. Organic coatings 2.2.8. Powder coating 2.2.9. Aluminium 2.2.10. Stainless steel 2.2.11. Copper 2.2.12. Lead 2.2.13. Zinc
2.3. Sacrificial protection 2.3.1. Cut edges 2.3.2. Passivity 2.3.3. Microcracking 2.3.4. Minimum radius 2.3.5. Oil-canning 2.3.6. Material 2.3.7. Installation 2.3.8. Distortion
2.4. Metal corrosion 2.4.1. Types of corrosion 2.4.2. Metal performance 2.4.3. The atmosphere 2.4.4. The rain 2.4.5. Pollutants 2.4.6. Atmospheric corrosion 2.4.7. Galvanic corrosion 2.4.8. The electrochemical or galvanic series 2.4.9. Galvanic table
2.5. Environment 2.5.1. Environmental categories 2.5.2. Special environments
2.6. Types of corrosion 2.6.1. Crevice corrosion 2.6.2. Pitting corrosion 2.6.3. Poultice corrosion 2.6.4. Inert catchment 2.6.5. Ponding 2.6.6. Capillary 2.6.7. Unwashed areas 2.6.8. Corrosion rate 2.6.9. Solar collectors
2.7. Compatibility 2.7.1. Dissimilar materials 2.7.2. Compatibility table 2.7.3. Runoff corrosion 2.7.4. Fall-out corrosion
2.8. Organic coating protection 2.8.1. Underside protection 2.8.2. Colour differential 2.8.3. Touch up 2.8.4. Lap priming 2.8.5. Strippable films
2.9. Fatigue
3 .0 LOADINGS
3.0.1. AS/NZS 1170: 2002 3.0.2. NZS 3604: 1999 3.0.3. Types of load
3.1. Performance under load 3.1.1. Deflection 3.1.2. Section properties 3.1.3. Continuity
3.2. Point load
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3.3. Wind load. (U.D.L.) 3.3.1. Pressure coefficients 3.3.2. Local pressure coefficients kl
3.4. Load calculation 3.4.1. Wind load calculation
3.5. Snow loads 3.6. Fastener withdrawal loads
3.6.1. Timber purlins 3.6.2. Steel purlins 3.6.3. Steel battens
3.7. Super imposed and construction loads 3.8. Testing 3.9. Wind load span graphs
3.9.1. Profile shape 3.9.2. Trapezoidal profiles 3.9.3. Miniature profiles 3.9.4. Purlin overhang
4 .0 . DESIGN
4.1. Heat 4.1.1. Conduction 4.1.2. Radiation 4.1.3. Convection 4.1.4. Thermal expansion and contraction 4.1.5. Temperature range 4.1.6. Roof cladding expansion provisions 4.1.7. Profile strength 4.1.8. End laps 4.1.9. Roof noise
4.2. Condensation 4.2.1 Clause E3 internal moisture 4.2.2. Condensation 4.2.3. Water vapour 4.2.4. Night sky radiation
4.3. Underlay 4.3.1. Types of underlay 4.3.2. Use of underlays and vapour barriers 4.3.3. Synthetic wraps 4.3.4. Cold roof construction 4.3.5. Warm roof construction 4.3.6. Durability 4.3.7. Passive ventilation 4.3.8. horizontal laying 4.3.9 Vertical laying 4.3.10. Underlay and vapour barrier support 4.3.11. Seperation
4.4. Vapour barriers 4.4.1. Types of vapour control layer 4.4.2. Special requirements
4.5. Cavity construction 4.5.1. Types of cavities 4.5.2. Roof cavities 4.5.3. Wall cavities 4.5.4. Vertical cladding 4.5.5. Ventilation 4.5.6. Drainage path 4.5.7. Cavity underlays 4.5.8. Battens 4.5.9. Fasteners
4.6. Ventilation 4.6.1. Intake vents 4.6.2. Exhaust vents 4.6.3. Mechanical vents
4.7. Insulation 4.7.1. Types of insulation 4.7.2. Insulation position 4.7.3. Counterbattens
4.8. Roof pitch 4.8.1. Minimum roof cladding pitch 4.8.2. Runoff 4.8.3. Snow 4.8.4. hail
4.9. Curved roofs 4.9.1. Spring curving 4.9.2. Laps 4.9.3. Transverse laps 4.9.4. Durability 4.9.5. Purlin spacing 4.9.6. Concave roofs 4.9.7. Pre-curved roofs 4.9.8. Roll curving 4.9.9. Crimp curving
5 .0 FLAShINGS
5.2. Flashing cover 5.2.1. Flashing laps 5.2.2. Flashing edges
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5.3. Flashing types 5.3.1. Ridge, and hip 5.3.2. Ridge - hip intersections 5.3.3. Barge and verge 5.3.3.1. Internal barge flashing 5.3.4. Parapet cappings 5.3.5. Apron flashings 5.3.5.1. Apron and parapet capping
terminations 5.3.5.2. Change of pitch 5.3.5.3. Step apron 5.3.5.4. Gutter apron 5.3.6 Valley 5.3.7. Soffit flashings 5.3.8. Flashings for vertical cladding 5.3.9. Flashings for horizontal corrugate
5.4. Fastening 5.4.1. Primary fasteners 5.4.2. Secondary fasteners 5.4.3. Secret fixing clips 5.4.4. Cleats 5.4.5. Seams 5.4.6. Flashing expansion 5.4.7. Expansion details 5.4.8. Building expansion joints
5.5. Curved flashings 5.5.1. Lockseamed flashings 5.5.2. Jennied flashings 5.5.3. Crimped flashings
5.6. Sealants 5.6.1. Properties 5.6.2. Methods of sealing 5.6.3. Surface preparation 5.6.4. Sealant extrusion and placement 5.6.4.1. Sealed laps 5.6.5. Strip sealants 5.6.6. Soldered joints
5.7. Profile closures 5.7.1. Vented fillers 5.7.2. Metal closures
5.8. Ridge vents 5.8.1. Ventilating ridging
6 .0 PENETRATIONS
6.1.1. Responsibility 6.1.2. Durability 6.1.3. Corrosion 6.1.4. Catchment 6.1.5. Obstruction 6.1.6. Discharge capacity 6.1.7. Sealing 6.1.8. Alternative materials
6.2. Penetration design 6.2.1. Nomenclature 6.2.2. Diverter and cricket designs 6.2.3. Installation 6.2.4. Laps 6.2.5 Details 6.2.6. Types of penetration flashing design 6.2.7. Type A soaker 6.2.8. Type B watershed 6.2.9. Type C tapered 6.2.10. Type D tray
6.3. Collar or boot flashings 6.3.1. Plant room and conduit penetrations
6.4. Window flashings for metal cladding 6.4.1 Flush window flashings 6.4.2. Recessed window flashings 6.4.3. Butt window flashings 6.4.4. Flashings for vertical cladding 6.4.5. Alternative flashing designs
6.5. Dormer junctions
7 .0 INSTALLATION
7.1. Pre-installation 7.1.1. Setting out and laying 7.1.2 Downturns 7.1.3. Stopends 7.1.4. Overhang 7.1.5 Cutting and drilling
7.2. Swarf 7.2.1. Swarf removal 7.2.2. Swarf damage
7.3. Fasteners 7.3.1. Primary fasteners 7.3.2. Nails 7.3.3. Screws
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7.4. Secondary fasteners 7.4.1 Rivets 7.4.2 Monel rivets 7.4.3 Aluminium rivets 7.4.4 Stainless steel rivets 7.4.5 Spacing 7.4.6. Fastener frequency
7.5. Fixing 7.5.1 Crest fixing 7.5.2. Pan fixing 7.5.3. Expansion fixings 7.5.4. Lap stitching
7.6. Installation 7.6.1. Driving 7.6.2. Tools 7.6.3. Modes of failure
7.7. Fastener loads 7.7.1. Load spreading washers 7.7.2. Sealing washers
7.8. Performance 7.8.1 Pull-out values 7.8.2 Pull-over values 7.8.3. Fastener durability 7.8.4. Corrosion 7.8.5. Coating thickness 7.8.6 Compatibility of fasteners 7.8.7. Purlin creasing
7.9. Fastening patterns 7.10. Reroofing 7.11 Fixing Aluminium Sheeting
8 .0 ROOF DRAINAGE
8.2.1. Catchment area 8.2.2. Capacity calculations 8.2.3. Profile capacity
8.3. Snow 8.3.1. hail
8.4. Gutters 8.4.1. Gutter installation 8.4.2. Gutter support systems 8.4.3. Eaves gutters 8.4.4. Internal gutters 8.4.5. Valley gutters 8.4.6. Fascia gutters
8.4.7 Concealed gutter systems 8.4.8. Secret gutters 8.4.9 Fall
8.5. Downpipes 8.5.1. Downpipe spreaders
8.6. Sumps 8.6.1. Rainwater heads 8.6.2. Outlets and overflows
9 .0 PLASTIC ROOFLIGhTING
9.2.1. Glass reinforced plastic. GRP 9.2.2. Polycarbonate 9.2.3. UPVC
9.3. Types of roof lights 9.4. Light transmission 9.5. Weathering and durability 9.6. Loadings
9.6.1. Point load. Walking traffic 9.6.2. U.D.L. wind and snow loads
9.7. Fixing 9.7.1. Side-lap fixing 9.7.2. Side-lap fixing between purlins 9.7.3. End laps 9.7.4. Span-breakers 9.7.5. Stopends 9.7.6. Purlin protection 9.7.7. Drainage 9.7.8. Condensation 9.7.9. Pitch
9.8. Thermal expansion 9.9. Transport, handling and storage
9.9.1. Maintenance
10.1. Design 10.1.1. Durability 10.1.2. Pitch 10.1.3. Underlays 10.1.4 Roof framing 10.1.5. Tiling battens
10.2. Roof drainage 10.2.1. Valleys 10.2.2. Valley installation
10.3. Flashings 10.3.1. Ridge
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10.3.2. Gable ends 10.3.3. hip 10.3.4. Vertical wall 10.3.5 Wall to roof junctions 10.3.6. Penetrations
10.4. Installation 10.4.1. Laying 10.4.2. Roof traffic 10.4.3. Workmanship
10.5. Sitework
11.0 SECRET F IxED CLADDING
11.1. Self supporting cladding 11.2. Fully supported roof and wall cladding
11.2.1. Types 11.2.2. Traditional architectural metal
panels 11.2.3. Long length strip roof cladding 11.2.4. Types of joints 11.2.5. Standing seam 11.2.6. Angle seam 11.2.7. Roll cap 11.2.8. Transverse laps
11.3 Materials 11.3.1. Copper 11.3.2. Zinc 11.3.3. Aluminium 11.3.4. Stainless steel 11.3.5. Coated steel
11.4. Loadings 11.4.1 Fixing 11.4.2. Substrate 11.4.3. Clips, cleats and fasteners
11.5. Underlay 11.5.1. Ventilation
11.7. Façade cladding 11.8. Edge finishes
11.8.1. Ridge and hip 11.8.2. Apron or abutment 11.8.3. Eaves and verge 11.8.4. Penetrations 11.8.5. Cappings
11.9. Durability
12.0 INSULATED PANELS
12.4.1. Supporting structure 12.5. Thermal
12.5.1. Fire 12.6. Condensation 12.7. Acoustic 12.8. Fixing 12.9. Flashings
13.0 MAINTENANCE
13.5.1. Installation 13.6. Washing
13.7. Overpainting 13.7.1. Unpainted cladding 13.7.2 Repainting painted claddings 13.7.3. Weathered with white corrosion 13.7.4. Red corrosion 13.7.5. Paint 13.7.6. Brush application 13.7.7. Roller application 13.7.8. Spray application
13.8. Material selection 13.8.1. Residential 13.8.2. Commercial 13.8.3. Responsibility & liability 13.8.4. Special environments and exclusions:
13.9. Drinking water
14.0 SITE PRACTICE
14.1. Safety 14.1.1. Responsibilities 14.1.2. Training
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14.1.3. Working at height 14.1.3.1. Roof edge protection 14.1.4. Residential and light commercial
roofing 14.1.5. Limitations of fall arrest and
travel restraint 14.1.6. Access 14.1.7. Scaffolding 14.1.8. Mobile scaffolds 14.1.9. Personal safety 14.1.10. Safety mesh 14.1.11. Timber fixing 14.1.12. Steel fixing
14.2. Transportation 14.3. Handling 14.4. Acceptance of materials
14.4.1. Presence of moisture between sheets 14.4.2. Colour match 14.4.3. Storage 14.4.4. Storage stain
14.5. Roof loading 14.6. Walking on roofs
14.6.1. Roof access during construction 14.6.2. Roof cladding damage
14.7. Completion 14.8. Tools of the trade
15.0 TESTING
15.1. Scope 15.2. Commentary on part 15.1 15.3. General methods of testing sheet roof and wall cladding 15.4. Commentary on part 15.3 15.5. Specific methods of testing sheet roof and wall cladding for point load 15.6. Commentary on part 15.5 15.7. Specific methods of testing sheet roof and wall cladding to determine their resistance to wind pressures (UDL - uniformly distributed load)
16.0 LIST OF MEMBERS OF ThE NZ METAL…
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