Can I Safely Remove Asbestos Millboard From Behind My Old Wood Burner?

Asbestos millboard behind an old wood burner is a serious health hazard, and in most situations you should not attempt to remove it yourself. NZ law places strict controls on asbestos removal work, and getting it wrong can put your family's health — and your legal standing — at real risk. Here's what you need to know before you touch anything.

What Is Asbestos Millboard?

Asbestos millboard is a dense, compressed sheet material that was widely used in New Zealand homes from the 1940s through to the late 1980s as a heat shield behind wood burners, fireplaces, and flued heaters. It looks similar to a grey or off-white cardboard-like sheet and was valued for its fire resistance. Because it was used directly behind high-heat appliances, it was often cut, drilled, and fitted tightly into place — all activities that can release dangerous asbestos fibres into the air.

If your wood burner was installed before the late 1980s, there is a real chance the backing board contains asbestos. Do not sand, drill, cut, or disturb it until you know what you're dealing with.

Is It Friable or Non-Friable?

Asbestos materials are classified as either friable (easily crumbled, releasing fibres readily) or non-friable (bonded, less likely to release fibres when undisturbed). Millboard behind a wood burner can be tricky — years of heat cycling may have made it more brittle and friable than it originally was. This classification matters enormously under NZ law because it determines who is legally allowed to remove it.

• Friable asbestos removal must always be carried out by a Class A licensed asbestos removalist.
• Non-friable asbestos removal of more than 10 m² must also be done by a Class B (or Class A) licensed removalist.
• Non-friable asbestos removal of less than 10 m² may be done by an unlicensed person, but only if they follow strict WorkSafe NZ guidelines, use appropriate PPE, and dispose of waste correctly.

Millboard behind a wood burner is almost always less than 10 m² in area — but the key question is whether it is friable. Given the heat exposure, treat it as potentially friable until proven otherwise.

Can a Homeowner Do It Themselves?

Technically, NZ regulations allow a homeowner to remove a small amount (under 10 m²) of non-friable asbestos themselves. However, in practice, millboard in this location is strongly recommended to be handled by a professional because:

• Heat damage may have made it friable, triggering the Class A licence requirement.
• Removing a wood burner involves disconnecting a flue, which may disturb additional asbestos materials (rope seals, flue tape, or backing behind the firebox).
• Incorrect removal and disposal carries serious legal and health consequences.
• WorkSafe NZ requires specific controls, PPE (P2 respirator, disposable coveralls), and approved disposal at a licensed facility — even for small DIY jobs.

If in doubt, don't do it yourself. The cost of professional removal is far outweighed by the risk to your health and your family's.

Getting the Material Tested First

Before any removal work begins, have the material sampled and tested by an accredited laboratory. A qualified asbestos assessor can take a sample safely and send it for analysis. This confirms whether asbestos is present and what type, and informs the correct removal approach. Do not take a sample yourself by breaking or scraping the board.

What Does Licensed Removal Involve?

A licensed asbestos removalist will:

1. Assess the material and prepare a removal control plan.
2. Isolate the work area and use appropriate containment.
3. Wet the material to suppress fibre release during removal.
4. Double-bag and label all waste as asbestos material.
5. Dispose of waste at a council-approved landfill that accepts asbestos.
6. Provide a clearance certificate once the area is safe.

The MBIE Building Performance website has guidance on asbestos in homes, and BRANZ provides technical information on identifying and managing asbestos in older NZ buildings.

Disposal Rules in New Zealand

Asbestos waste cannot go in your general rubbish or skip bin. It must be double-wrapped in heavy-duty polythene, clearly labelled, and taken to a landfill licensed to accept asbestos waste. Your local council can advise on approved disposal sites in your region. Illegal dumping of asbestos carries significant fines.

What About the Wood Burner Itself?

Removing or replacing a wood burner may also require a building consent, depending on your council and the scope of work. Flue connections and hearth specifications are covered under the NZ Building Code. Always check with your local council before disconnecting or relocating a solid fuel heater. You can find more about consent requirements at MBIE Building Performance.

When to Call a Professional

You should always engage a licensed asbestos removalist if:

• The millboard is crumbly, powdery, or has been damaged by heat.
• You are unsure whether the material is friable or non-friable.
• There is more than 10 m² of material (unlikely here, but check).
• You want a clearance certificate for insurance or sale purposes.
• You are a landlord — Tenancy Services Healthy Homes standards mean you have additional obligations to protect tenants.

A qualified asbestos removal specialist will carry the right licence, insurance, and equipment to do the job safely and legally. You can find licensed asbestos removal specialists in your area right here on tradedirectory.co.nz.

Sources & Further Reading

• WorkSafe NZ – Asbestos guidance for homeowners
• MBIE Building Performance – Asbestos in homes
• BRANZ – Identifying asbestos in older buildings
• Tenancy Services – Healthy Homes Standards
• Standards NZ – Relevant NZ standards