Choosing between Colorsteel and concrete tile roofing is one of the biggest decisions a New Zealand homeowner will make — your roof protects everything underneath it and can last several decades if chosen and installed correctly. Both materials are widely used across New Zealand, but they suit different homes, climates, and budgets. This guide walks you through the key differences so you can make a confident, informed choice.
What Is Colorsteel Roofing?
Colorsteel is a New Zealand Steel brand of pre-painted, zinc/aluminium-alloy-coated steel sheet, roll-formed into profiles such as corrugate, tray, and standing seam. It is manufactured locally and is one of the most common roofing materials in New Zealand. Common profiles include corrugate (the classic Kiwi look), Hi-Rib, and concealed-fix tray systems.
Key characteristics:
- Lightweight — typically 4–7 kg/m², placing minimal load on the structure
- Low minimum pitch — many profiles can be installed at pitches as low as 3–5°
- Long service life — quality Colorsteel products carry manufacturer durability warranties; check the specific product datasheet
- Recyclable at end of life
- Available in a wide range of colours, including Colorsteel Endura® and Maxx® grades for harsh environments
What Is Concrete Tile Roofing?
Concrete tiles are cast from sand, cement, and pigment, then cured to form a hard, dense roofing unit. Brands such as Monier (now part of Boral) and Fletcher Roofing have supplied concrete tiles across New Zealand for decades.
Key characteristics:
- Heavy — typically 40–55 kg/m², which is roughly 6–10 times heavier than steel roofing
- Minimum pitch — generally 17.5° or steeper (always confirm with the manufacturer and your designer)
- Thermal mass — the density moderates temperature swings inside the roof space
- Colour fade — pigment is surface-applied; tiles may need recoating over time
- Requires a robust framing structure to carry the load
How NZ Climate Affects Your Choice
New Zealand's climate varies enormously, and this directly affects roofing performance.
| Climate Zone | Colorsteel Considerations | Concrete Tile Considerations |
|---|---|---|
| Coastal / marine | Specify Colorsteel Maxx® or Endura® for salt-air resistance; maintain clearances from vegetation | Tiles are generally salt-tolerant but mortar bedding and ridge caps need regular inspection |
| High UV (Northland, Hawke's Bay) | UV-stable paint systems; lighter colours reduce heat gain | Tiles fade over time; recoating adds cost |
| High rainfall (West Coast, Fiordland) | Excellent water-shedding at low pitch; keep gutters clear | Steeper pitch required; moss and lichen growth common in wet climates |
| Cold / alpine (Central Otago, Canterbury high country) | Handles snow load well at correct pitch; thermal movement must be designed for | Heavy snow load adds to already significant structural demand |
| High wind (Wellington, exposed coastal) | Concealed-fix profiles perform well; fixings must meet NZS 3604 wind zone requirements | Tiles must be mechanically fixed, not just bedded, in high-wind zones |
Always consult a qualified roofing contractor who knows your specific local conditions.
Structural Implications
This is one of the most important practical differences. Concrete tiles are significantly heavier than Colorsteel, and your roof framing must be designed to carry the load safely under NZS 3604 timber framing and NZ Building Code clause B1 (Structure).
- New builds can be designed for either material from the outset.
- Re-roofing an existing home from tiles to steel (or vice versa) may require a structural assessment. Switching from steel to concrete tiles almost always requires an engineer to check the existing framing — do not skip this step.
- A Licensed Building Practitioner (LBP) or structural engineer can advise; find one at lbp.govt.nz.
Durability and Maintenance
Colorsteel
- Cut edges and penetrations must be sealed to prevent corrosion — this is a common maintenance point
- Keep leaves and debris off the roof; organic matter holds moisture and accelerates corrosion
- Inspect fixings, flashings, and sealants every few years
- Repainting is possible but rarely needed within the warranty period if the correct grade was specified
Concrete Tiles
- Moss and lichen growth is common in shaded or damp areas; treat and clean periodically
- Ridge cap mortar can crack and lift over time — inspect after major storms
- Individual cracked or broken tiles can be replaced without disturbing the whole roof
- Surface recoating (painting or sealing) extends appearance and weather resistance
BRANZ publishes research on roofing durability and maintenance best practice that is well worth reading before you commit to a material.
Building Consent and Compliance
Whether you need a building consent depends on the scope of work:
- Like-for-like re-roofing (same material, same profile) may qualify as a Schedule 1 exemption under the Building Act — but always confirm with your local council before starting work, as exemptions have conditions.
- Changing roofing material (e.g., tiles to steel) or altering the roof structure almost always requires a building consent.
- All roofing work must comply with NZ Building Code clause E2 (External Moisture) to prevent water ingress.
- Flashings around penetrations (skylights, pipes, chimneys) are a critical compliance point.
Cost Drivers — What Affects the Price?
Neither Colorsteel nor concrete tile roofing has a single fixed price — costs vary based on:
- Roof complexity — hips, valleys, dormers, and penetrations all add labour time
- Pitch and height — steeper or higher roofs require more safety equipment and time
- Removal and disposal of the existing roof
- Structural remediation if framing needs upgrading
- Material grade — standard vs. coastal-grade Colorsteel; standard vs. premium tile profile
- Region — labour rates and material freight costs vary across NZ
Always get multiple written quotes from qualified tradespeople, include a contingency in your budget for unexpected findings (rot, damaged sarking, corroded fixings), and confirm what is and is not included in each quote.
DIY vs. Professional Installation
Roofing is not a suitable DIY project for most homeowners:
- Working at height is one of the leading causes of serious injury and death in NZ. WorkSafe NZ requires appropriate fall protection for any work at height.
- Incorrect installation voids manufacturer warranties and can cause Building Code non-compliance.
- Flashings and penetration sealing require skill and experience to get right.
- If a building consent is required, the work must be carried out or supervised by an LBP in the relevant licence class.
When to Call a Professional
Call a qualified roofing contractor or LBP if you are:
- Planning a full re-roof or material change
- Noticing leaks, lifted tiles, or rust staining inside the roof space
- Buying or selling a home and want a roof condition report
- Unsure whether your existing framing can carry a heavier material
- Dealing with any consent or compliance question
You can find qualified local roofing tradespeople on tradedirectory.co.nz. Check that any contractor you hire holds a current LBP licence (verify at lbp.govt.nz), carries public liability insurance, and can provide references from recent similar projects.
Practical Tips for Getting Good Value
- Get at least three written quotes and ensure they cover the same scope of work
- Ask each contractor to specify the exact product grade (e.g., Colorsteel Endura® vs. standard) so you are comparing like with like
- Check qualifications and references before signing anything
- Use quality materials suited to your specific NZ conditions — the cheapest option upfront is rarely the cheapest over 30 years
- Plan your project budget carefully and include a contingency for unexpected findings
- Consult with qualified NZ tradespeople who understand local conditions, building codes, and best practices — New Zealand's climate varies significantly from north to south, affecting material choices and maintenance requirements
Sources & Further Reading
- BRANZ — Building Research Association of NZ — independent research on roofing materials and durability
- MBIE Building Performance — NZ Building Code — consent requirements, E2 external moisture, B1 structure
- Licensed Building Practitioners — verify your contractor's licence
- WorkSafe NZ — Working at Height — safety requirements for roofing work
- Standards NZ — NZS 3604 — timber framing standard referenced in roofing structural design
Roofing Association of NZ (RANZ)
Licensed Building Practitioner (LBP)
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