Until it's tested, treat it as asbestos
Don't cut, drill, sand, water-blast or walk on a roof that might be asbestos cement. Health NZ warns the sheets break easily and you could fall through, and WorkSafe says you can't tell asbestos by looking, so if you're unsure, assume it is. If some has already been broken, keep people and pets away and get advice before anyone cleans up.
Which roofs does this apply to?
WorkSafe lists asbestos cement roof sheeting and ridge capping, gutters, downpipes, gables and eaves, and panels such as Super Six among the places asbestos turns up in homes built before 1 January 2000.
Metal tiles can carry it too. Gerard says tiles made before the early 1980s often had small amounts in the mastic or bitumen coating, and Resene names decramastic and early Harvey tiles. Unsure about yours? Start with is my roof asbestos?
Do you have to remove it?
No. Health NZ says undamaged asbestos material isn't a risk just by being there, and lists leaving it, sealing, enclosing or removing it as the options. Removal makes sense when sheets are weathered, cracked or leaking, or a re-roof or renovation would disturb them anyway.
Think about the ceiling space too. Health NZ says it can hold high concentrations of asbestos dust under a weathered, brittle roof, so ask whether it should be checked as part of the job.
Who's allowed to remove it?
Removing more than 10 square metres of non-friable asbestos, counted over the whole job, needs a Class B or Class A licence. Friable asbestos, the kind that crumbles to powder by hand, needs Class A. WorkSafe says a big area can't be split into small sections to dodge the licence.
WorkSafe keeps a public register of removalists: check the licence shows as Current, not Suspended, Expired or Cancelled. Asbestos licences come from WorkSafe and LBP licences from MBIE's scheme, so the removal and the new roof may be two businesses. Ask whose name goes on each.
Health NZ says the asbestos regulations don't cover work on your own home, but recommends keeping DIY under 10 square metres. A whole roof is a fall risk as well as an asbestos one, so hand it over.
How a licensed removal runs
Test and a written plan
A sample is tested, then you get a written quote or work plan. WorkSafe says it should cover the work, tests, timing, warranties, safety measures and disruption to your home.
WorkSafe is notified
The removalist must notify WorkSafe in writing at least 5 days before licensed removal starts.
You and the neighbours are told
As far as reasonably practicable, the removalist tells whoever ordered the work, the owner and occupier, and nearby neighbours when it will start.
Careful removal
Businesses can't use water spray over 350 kPa, compressed air, or power tools and brooms without capturing the dust. Old sheets can't be reused.
Sealed and taken away
Waste is sealed in clearly marked containers and taken to a site the council has approved for asbestos.
Independent clearance
The area is inspected by an independent licensed assessor for Class A work, or an independent competent person for other work. You get a written clearance certificate stating no visible asbestos residue was found.
Then the new roof
Ask how soon the new roofing follows the clearance, and what keeps the weather out in between.
MBIE's guidance says taking a roof off a building of up to 3 storeys doesn't need consent if the primary structure isn't affected. For the replacement, a comparable product in the same position is generally exempt, and so is going lighter: MBIE's example is old clay tiles replaced with longrun or pressed metal tiles. Heavier needs consent, and some councils are stricter about a change of roofing type, so check with yours. Consented roofing must be done or supervised by an LBP. See re-roofing.
Get these in writing before work starts
- The test result, and which parts of the roof were sampled
- The removalist's business name, licence class and number, checked as Current on WorkSafe's register
- The work plan: scope, timing, safety measures and disruption
- Where the waste is going
- Who arranges the clearance inspection, and that you'll get the certificate
- Whether the ceiling space, spouting, downpipes and barges are included
- Who does the new roof, and the consent position for it
- For residential work of $30,000 or more including GST, a written contract and the official disclosure information
Landlords and insurance
If you rent the house out, WorkSafe says you're a PCBU (a business duty holder) when work is done on it, and where it could expose people to asbestos you need an asbestos management plan.
Insurers generally won't pay to replace a roof that has simply aged. Still tell your insurer before work starts, since cover may not apply during renovations.
Your part, and the professionals'
You can
- Find out when the house was built and the roof went on
- Note cracks, broken corners or heavy moss on the sheets, from the ground
- Keep everyone off the roof until it's tested, tradies included
- Keep the test result and clearance certificate together
Leave to a roofer
- Sampling and laboratory testing
- Removal over 10 square metres, which means any whole roof
- Checking the ceiling space for dust
- The new roof, any consent and the Record of Work
What we'd do about an asbestos roof
If it's sound and nothing is changing, we'd leave it alone and keep everyone off it. If it's cracked, leaking or in the way of a renovation, we'd get it tested, book a removalist whose licence shows as Current, and plan the new roof alongside so the house isn't left exposed. When you're ready, we'll pass your job to one checked local roofer, and you can ask them how they handle the licensed removal.
Want a roofer to take a look?
Tell us the job and your postcode. We match it with a Find My Roofer certified roofer who specialises in that kind of work, and they call you to quote. Your number goes to them alone.