Winter is the most dangerous time to be on a roof in New Zealand. Wet corrugated iron is as slippery as ice, southerly squalls arrive with little warning, and shorter days mean more jobs pushed into low-light conditions. Yet the pressure to keep revenue flowing means plenty of tradies take risks they wouldn't dream of in January.
This guide covers what WorkSafe NZ requires for height work, what changes in winter, and the practical steps that keep you legal, insured — and alive.
Why Winter Raises the Risk Profile
Between May and August, New Zealand roofing conditions change dramatically:
- Wet roofing iron reduces friction coefficients to near zero. A 15-degree pitch that's safe in dry conditions becomes a slip hazard as soon as dew or drizzle hits.
- Wind loading increases. Even a 40 km/h gust can unbalance a tradie carrying roofing sheets or a pack of nails. Southerly winds regularly exceed 60 km/h on exposed South Island and lower North Island sites.
- Light degrades. Sunrise is as late as 7:45 am in southern cities in June, and overcast skies reduce contrast, making footing hard to judge.
- Condensation on valley iron and flashings creates hidden slippery patches not visible from the ground or even from standing height.
The result: ACC records consistently show a spike in fall-related serious harm claims from tradies between June and August each year. Many involve falls of less than three metres — which is precisely why WorkSafe's rules apply well before the heights most tradies consider "serious."
WorkSafe NZ Height Safety Requirements
Under the Health and Safety at Work (General Risk and Workplace Management) Regulations 2016, a PCBU (your business, whether sole trader or company) must manage fall risks wherever work involves a fall of more than one metre if it could cause harm.
For roofing work specifically, WorkSafe's good practice guidelines require:
Falls of 1–3 Metres
You must either: - Use physical fall prevention (edge protection, scaffolding, barriers), or - Use a fall restraint system (harness and lanyard anchored to a certified anchor point), or - Demonstrate an equivalent safe system with documented risk assessment
A simple ridge-and-harness setup anchored to the apex qualifies at this height range, provided the anchor point is rated to at least 12 kN (most dedicated roof anchors are) and the system prevents the worker reaching any open edge.
Falls Greater Than 3 Metres
At this height, fall arrest systems (which catch you after a fall) require full energy-absorbing lanyards rated to WorkSafe standards. Scaffolding or perimeter edge protection becomes far more practical for sustained roofing work. For steep-pitch work (greater than 26 degrees), scaffolding is almost always the safer and more cost-effective answer.
Key WorkSafe principle: the hierarchy of controls applies — you must eliminate the fall risk if practicable. "Practicable" accounts for cost, so smaller repair jobs may legitimately use restraint rather than full scaffolding, but that assessment needs to be documented.
Anchor Points
Roof anchor points must comply with AS/NZS 1891.4 (Industrial Fall Arrest Systems). Permanent anchors on existing roofs should be tagged and dated — if you're uncertain about the rating of an old anchor, treat it as uncertified and install your own for the job. Temporary anchors (strap-style, wrap-around ridge systems) are widely available from NZ suppliers for around $80–$150 per anchor, and most are rated for single-person use.
Specific Winter Hazards and Controls
Wet Iron Roofing
Never step directly onto wet corrugated iron or tray decking without roof brackets (also called chicken ladders or roof hooks). These hook over the ridge and distribute your weight across multiple sheets. A pair of good-quality aluminium roof ladders costs around $200–$350 and is tax-deductible as a tool of trade — see how to claim vehicle and equipment expenses as a NZ tradie.
Rubber-soled footwear (specifically designed for roofing) provides significantly better grip than standard steel-capped boots on wet iron. This is equipment you can legitimately charge to the job.
Wind
WorkSafe expects you to have a documented wind threshold in your site safety plan beyond which work on the roof stops. A widely used industry benchmark is suspending roof work when sustained wind speeds exceed 40 km/h or gusts exceed 60 km/h. Check MetService forecasts before mobilising to a roofing job; the hourly forecast for most NZ locations is free at metservice.com.
When wind causes a delay, notify the client promptly and document it. If you're working under a fixed-price contract, wet weather delay provisions matter — see fixed-price vs cost-plus contracts for NZ tradies for how to build weather contingencies into your quotes.
Low Light Conditions
If you're working in conditions where you cannot clearly see your footing — at dawn, dusk, or under heavy cloud — stop. WorkSafe's obligation is harm prevention, not production targets. A portable work light ($80–$200 from most trade suppliers) is worth it if you regularly start early or finish late.
Pricing Winter Roofing Jobs Correctly
Winter roofing jobs cost more to do safely. This is not optional padding — it is real cost. Build the following into your quotes:
- Scaffold hire: A basic scaffold setup for a standard residential roof runs $800–$2,500 per week depending on the size and your region. For larger re-roofing contracts, include at least two weeks' hire as a default.
- Extra labour time: Allow 15–25% more labour hours for winter conditions. Moving carefully on wet iron, setting up and taking down fall protection, and managing clothing layers all slow down the job.
- Anchor hire or purchase: If you don't own roof anchors, hire them. If you're doing regular roofing work, owning your own set and amortising the cost across jobs is more efficient.
- Weather contingency: Add a 5–10% weather contingency allowance to fixed-price roofing quotes and make it clear in writing. Clients appreciate the transparency.
Use our roofer pricing guide for NZ 2026 as a starting point for labour rate benchmarks by region.
Documentation WorkSafe Expects
If you're inspected following an incident (or even a near-miss), WorkSafe will ask for:
- Site-specific safety plan including fall risk assessment
- Evidence of equipment inspection (harnesses, lanyards, anchor tags)
- Worker training records — have your team completed a Working at Height course? NZQA unit standards 23229 and 15757 cover this specifically
- Tool-box talk or pre-start safety meeting records for the day of the incident
None of this needs to be elaborate. A one-page safety plan, a photo of your equipment tags on your phone, and a WhatsApp message to your team confirming the pre-start talk is documented evidence. The key is that it exists.
If you're running a team on multiple sites, Fastcrew (fastcrew.nz) allows you to attach site safety notes and equipment checks to each job, so every crew member on-site can confirm they've read the safety plan before work begins. That confirmation is timestamped and auditable.
What Happens If You Don't Comply
WorkSafe NZ can issue improvement notices, prohibition notices (stopping work on site), or infringement fines. Serious falls that result in harm trigger formal investigations. Fines for PCBU breaches of the Health and Safety at Work Act 2015 reach $1.5 million for companies and $300,000 for individuals for the most serious category-one offences.
Beyond fines, an at-fault injury may void your professional indemnity and public liability insurance — check your policy wording carefully. Most NZ tradie insurers require you to have "complied with all relevant legislation" for coverage to apply.
ACC levies for roofers are already among the highest in the trades sector (see our ACC levies guide for NZ tradies). An at-fault serious harm claim can result in an experience-rated levy increase that follows your business for years.
Practical Winter Roofing Checklist
Before each roofing job this winter:
- [ ] Check MetService forecast — wind and rain for the work window
- [ ] Inspect harness, lanyard and anchor point — tags current and within rated service life
- [ ] Confirm roof brackets/chicken ladders are on the trailer
- [ ] Brief crew on site hazards, wind threshold and stop-work criteria
- [ ] Document pre-start briefing (photo, message, or app entry)
- [ ] Set client expectation: wet weather may cause delays, will notify same morning
Download our free NZ tradie templates at tradietools.nz/templates/ — including a one-page height work risk assessment template, site safety plan template, and weather delay notification letter you can send to clients.
NZ Tradie Tools provides free calculators, templates and guides for New Zealand tradies. Visit tradietools.nz.