Removing asbestos cement ridge capping yourself is technically permitted for homeowners in New Zealand under certain conditions — but it is not something to take lightly. Asbestos fibres are a proven cause of serious lung diseases including mesothelioma, and ridge capping work puts you at height on a roof, adding significant safety risk on top of the health hazard. Before you pick up a pry bar, read this carefully.
Understanding the Regulations
In New Zealand, asbestos removal is governed by the Health and Safety at Work (Asbestos) Regulations 2016, administered by WorkSafe NZ. Under these regulations:
- Class A asbestos removal (friable or damaged asbestos) must be carried out by a licensed Class A removalist.
- Class B asbestos removal (non-friable, bonded asbestos in good condition — which includes intact asbestos cement ridge capping) can be done by a homeowner on their own home, provided the total area is less than 10 square metres.
- If the area exceeds 10 m², a licensed Class B removalist is legally required.
Asbestos cement (AC) ridge capping is generally considered non-friable (bonded) asbestos when it is in good condition — meaning the fibres are locked into the cement matrix and less likely to become airborne. However, if the capping is cracked, crumbling, or weathered, it can behave more like friable asbestos and should be treated with extreme caution. When in doubt, engage a licensed specialist.
Is It Actually Asbestos?
Asbestos cement products were widely used in New Zealand homes built before 1990, including roofing, cladding, eaves, and ridge capping. If your home was built or reroofed before 1990, there is a real chance the ridge capping contains asbestos. You cannot identify asbestos by sight alone — the only way to confirm is to have a sample tested by an accredited laboratory. Many licensed asbestos assessors offer this service. Do not attempt to break off a sample yourself; instead, contact a professional.
What Homeowners Can Legally Do (Under 10 m²)
If you have confirmed the material contains asbestos, the area is under 10 m², and the capping is in good (non-friable) condition, here is the standard safe-work approach:
Personal Protective Equipment (PPE)
- Wear a P2-rated (half-face) respirator — not a dust mask.
- Wear disposable coveralls, gloves, and eye protection.
- Remove and bag all PPE before leaving the work area.
Preparation
- Wet the ridge capping thoroughly with water (add a small amount of PVA or wetting agent) to suppress dust. Keep it wet throughout the job.
- Lay heavy-duty polythene sheeting on the ground below to catch any debris.
- Keep bystanders, children, and pets well away from the area.
Removal
- Work carefully and slowly — do not use power tools, angle grinders, or anything that will cut, drill, or abrade the material.
- Remove fixings gently and lift the capping in whole pieces where possible.
- Do not drop or break the pieces.
Disposal
- Double-bag all asbestos waste in heavy-duty polythene bags (minimum 0.2 mm thick), seal with tape, and label clearly as "Asbestos Waste".
- Contact your local council to find an approved asbestos disposal site — not all transfer stations accept asbestos, and requirements vary by region.
- Never put asbestos waste in your general rubbish or skip bin.
After the Work
- Wipe down tools with a damp cloth and dispose of the cloth as asbestos waste.
- Shower and wash your work clothes separately.
Roof Safety — A Separate but Serious Risk
Working at height on a roof carries its own risks entirely separate from asbestos. Falls from roofs are a leading cause of serious injury and death in New Zealand. WorkSafe NZ requires that anyone working at height takes appropriate precautions, including the use of scaffolding, roof anchors, or harness systems. Do not attempt this work without proper fall protection in place.
When to Call a Professional
You should engage a licensed asbestos removalist if:
- The total area of ridge capping exceeds 10 square metres.
- The material is cracked, crumbling, or in poor condition.
- You are not confident in your ability to work safely at height.
- You are unsure whether the material actually contains asbestos.
- You are a landlord — under the Healthy Homes Standards, you have additional obligations to maintain safe rental properties.
A licensed Class B or Class A removalist will have the training, equipment, and insurance to handle the job safely and legally. They can also arrange compliant disposal. You can find qualified asbestos removal specialists in your area on tradedirectory.co.nz.
For guidance on whether your project requires a building consent, check with your local council. Reroofing work may fall under Schedule 1 exemptions of the Building Act, but this depends on the scope of work — always confirm before starting.
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