For most average New Zealand homes, a full reroof takes somewhere between 3 and 7 working days from start to finish. That said, the actual timeline depends on a range of factors — from the size and pitch of your roof to the material you choose and the weather on the day. Here's what you need to know before your project gets underway.
What Counts as an 'Average' NZ House?
When roofers talk about an average NZ home, they're generally thinking of a single-storey or straightforward two-storey house with a roof area of roughly 150–250 square metres. A simple gable or hip roof with few penetrations (skylights, chimneys, flues) is the easiest to work with. More complex rooflines — multiple valleys, dormers, or steep pitches — will add time and cost.
Typical Timelines by Roofing Material
The material you choose has a big influence on how long the job takes:
| Roofing Material | Typical Duration (average home) |
|---|---|
| Corrugated or tray steel (e.g. Colorsteel) | 3–5 working days |
| Longrun steel roofing | 3–5 working days |
| Concrete or clay tiles | 5–8 working days |
| Asphalt shingles | 4–6 working days |
| Butynol or membrane (flat roofs) | 2–4 working days |
Steel roofing is generally the fastest to install and is by far the most common choice in New Zealand. Tile roofs take longer because each tile must be individually fixed and cut around penetrations.
Key Factors That Affect the Timeline
Roof Size and Complexity
A larger roof with multiple hips, valleys, skylights, or a chimney will take considerably longer than a simple gable. Every penetration requires careful flashing work to meet the requirements of NZ Building Code clause E2 (External Moisture), which governs weathertightness.
Stripping the Old Roof
Before new material goes on, the old roofing must come off. This alone can take half a day to a full day for a standard home. If there's more than one layer of old roofing, or if the underlying sarking or purlins are damaged and need replacing, expect extra time.
Structural Repairs
Once the old roof is stripped, your roofer may find rotted timber, damaged purlins, or other issues that need fixing before the new roof goes on. This is common in older NZ homes and can add one to several days depending on the extent of the damage. Any structural timber repairs to the roof framing may need to comply with NZS 3604 (Timber-framed buildings) and could require a building consent — always check with your local council.
Weather
New Zealand weather is notoriously changeable. Roofers cannot safely work in high winds or heavy rain, and wet timber or substrate can cause long-term moisture problems if covered over. Your roofer will likely build some weather contingency into the schedule. WorkSafe NZ sets clear guidelines around working at height in adverse conditions.
Crew Size
A larger, experienced crew can complete a reroof significantly faster than a sole operator. Most residential roofing companies send teams of two to four tradespeople.
Do You Need a Building Consent?
This is a common question. In many cases, a like-for-like reroof (replacing the same material in the same location) may be exempt from building consent under Schedule 1 of the Building Act. However, this is not always straightforward — for example, if you're changing the roofing material or making structural changes, consent is likely required. Always confirm with your local council before work begins. You can find general guidance at MBIE Building Performance.
What Happens During a Reroof?
A typical reroof follows this sequence:
- Scaffolding and site setup — safety scaffolding is erected around the perimeter (required under WorkSafe regulations for most residential reroofs).
- Strip off old roofing — old iron, tiles, or membrane is removed and disposed of.
- Inspect and repair substrate — purlins, sarking, or roof framing are checked and repaired as needed.
- Install underlays — a breathable roofing underlay is laid to provide a secondary weatherproofing layer.
- Fix new roofing material — sheets, tiles, or membrane are installed.
- Flashings and penetrations — valleys, ridges, gutters, and all penetrations are carefully flashed and sealed.
- Clean up and inspection — debris is cleared and the finished roof is inspected.
When to Call a Professional
Roofing work that involves the weathertightness envelope of a house is restricted building work in New Zealand. This means the work must be carried out or supervised by a Licensed Building Practitioner (LBP) with the appropriate licence class. Attempting a full reroof yourself without the right licence is not only potentially unsafe — working at height is one of the leading causes of serious injury on NZ worksites — but may also affect your home's insurance cover and ability to sell. Always hire a qualified, licensed roofer. You can find experienced local roofing professionals on tradedirectory.co.nz.
For technical guidance on roofing systems and weathertightness, BRANZ is an excellent independent NZ resource.
Roofing Association of NZ (RANZ)
Licensed Building Practitioner (LBP)
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