Walking on a wet roof is one of the most hazardous tasks a homeowner can attempt — and in New Zealand's frequently damp climate, it's a risk that comes up more often than you'd think. The short answer is: if the roof is wet, the safest option is to wait until it is dry. If you absolutely must access a wet roof, the steps below will help you minimise the risk of a serious fall.
Understand the Risks First
Falls from height are a leading cause of serious injury and death in New Zealand. Even a single-storey roof can be fatal if you fall from it. Wet surfaces — whether metal, concrete tile, clay tile, or painted roofing — dramatically reduce friction underfoot. WorkSafe NZ treats roof work as a high-risk activity, and their guidance applies to homeowners as much as it does to tradespeople. Before you go up, honestly ask yourself whether the task is urgent enough to justify the risk.
Essential Safety Gear Before You Step On
Never access a wet roof without the right personal protective equipment (PPE) and fall-arrest measures in place.
- Non-slip footwear: Wear rubber-soled boots or shoes with a soft, grippy sole. Avoid smooth-soled shoes, jandals, or worn-out sneakers. Dedicated roofing boots are available from trade suppliers.
- Fall-arrest harness: A properly fitted safety harness connected to a secure anchor point is the single most important piece of equipment. Harnesses and roof anchors are available at Bunnings and Mitre 10. Make sure any anchor point is rated for fall arrest and is fixed to a structural element — not just the roofing material.
- Roof ladder or chicken ladder: A roof ladder (also called a chicken ladder or roof hook ladder) hooks over the ridge and distributes your weight across multiple battens or purlins. This is essential on pitched roofs and greatly reduces slip risk.
- Gloves: Protect your hands and improve grip if you need to steady yourself.
- A spotter on the ground: Never work on a roof alone. Have someone on the ground who can call for help if something goes wrong.
Safe Movement Techniques on a Wet Roof
Once you are properly equipped and anchored, how you move matters enormously.
Move Slowly and Deliberately
Rush is your enemy on a wet roof. Take small, deliberate steps and keep your centre of gravity low. Avoid sudden movements or reaching too far to one side.
Keep Three Points of Contact
Whenever possible, maintain three points of contact with the roof surface — two feet and one hand, or two hands and one foot. This is standard practice in height safety.
Walk on the Structural Lines
On corrugated iron or ribbed metal roofing (common on NZ homes), walk along the ribs or ridges, not the pans (the flat valleys between ribs). The ribs sit directly over the purlins and are structurally stronger. On tiled roofs, step on the overlap area near the top of each tile where it is supported, never on the unsupported lower portion.
Use the Roof Ladder as Your Primary Surface
Ideally, you should be stepping on the roof ladder rungs rather than the roofing material itself. The ladder spreads load and gives you a consistent, less slippery surface to work from.
Avoid Painted or Moss-Covered Surfaces
Old painted roofs and roofs with moss or lichen growth are especially treacherous when wet. Moss holds moisture and acts almost like a lubricant underfoot. If your roof has significant moss growth, consider having it treated before any access is attempted. A professional roof painter can assess and treat moss safely.
NZ Weather and Roof Surface Considerations
New Zealand's climate means roofs are frequently wet — not just during rain, but from morning dew, sea spray in coastal areas, and persistent shade in south-facing situations. Zincalume and Colorsteel metal roofing becomes extremely slick when wet. Concrete and clay tiles are similarly hazardous. Even a light drizzle is enough to make a roof dangerous.
If you are planning roof painting or maintenance, check the weather forecast carefully. Most roof coating manufacturers, including those whose products are stocked at Resene and Dulux, specify minimum dry conditions for application — so waiting for a dry spell is not just a safety issue, it's also a product performance issue.
Setting Up Safe Roof Access
- Use a ladder that extends at least 1 metre above the roof edge and is secured at the base and tied off at the top where possible.
- Place the ladder on firm, level ground. Never lean a ladder against guttering — it can collapse under load.
- Check that your roof structure can take your weight. On older homes, sarking boards or purlins may be deteriorated. If in doubt, have a builder assess the structure first.
- Be aware of fragile roof materials such as fibreglass or translucent sheeting, which may not support your weight at all.
When to Call a Professional
For most homeowners, wet roof access is best left entirely to qualified professionals. A licensed roof painter or roofing contractor has the correct fall-arrest equipment, training, and experience to work safely at height. They also carry the appropriate insurance — if you are injured on your own roof without proper precautions, your home insurance may not cover the incident.
If your roof needs painting, cleaning, moss treatment, or any maintenance, find a qualified local roof painter on tradedirectory.co.nz. For any structural roofing work, check whether a building consent is required through MBIE Building Performance or your local council — some repairs fall under Schedule 1 exemptions, but it pays to confirm before you start.
For guidance on height safety standards in New Zealand, WorkSafe NZ publishes detailed resources on working at height that are worth reading before any roof access.
Master Painters NZ member
Licensed Building Practitioner (LBP)
Roofing Association of NZ (RANZ)
