How to Safely Wet-Wipe Surfaces After Accidental Asbestos Cement Breakage

Accidentally breaking asbestos cement — whether it's an old corrugated roof sheet, a soffit panel, or a wall cladding board — is stressful, but staying calm and following the right steps will minimise your exposure to harmful fibres. Wet-wiping is the recommended method for cleaning hard surfaces after minor, localised asbestos cement disturbance, because dampening the material prevents fibres from becoming airborne. This guide covers the correct process for NZ homeowners dealing with a small, accidental breakage.

Important: This guidance applies only to minor, incidental disturbance of bonded asbestos cement (e.g. a single broken sheet or panel). Any deliberate removal, large-scale disturbance, or work in a commercial or rental property is likely to require a licensed asbestos removalist under the Health and Safety at Work (Asbestos) Regulations 2016. When in doubt, stop work and seek professional advice.

Understand What You're Dealing With

Asbestos cement (sometimes called fibro or AC sheet) is a bonded material — the asbestos fibres are locked into a cement matrix. When intact, it poses a low risk. When broken, cut, or sanded, fibres can be released. Common NZ examples include:

• Corrugate roofing and guttering (pre-1990s)
• Soffit linings and eaves
• Flat wall cladding sheets
• Fence panels

If you are unsure whether a material contains asbestos, do not disturb it further. Arrange for a sample to be tested by an accredited laboratory before proceeding. WorkSafe NZ provides guidance on identifying asbestos-containing materials.

Gather Your PPE and Supplies Before You Start

Never begin clean-up without the right personal protective equipment (PPE) and materials. You will need:

• P2-rated disposable respirator (not a basic dust mask — it must be P2 or higher)
• Disposable coveralls (Tyvek-style, hooded)
• Nitrile or rubber gloves
• Safety glasses or goggles
• A garden sprayer or spray bottle filled with water (a few drops of dish soap helps the water penetrate)
• Disposable cloths or rags (not a vacuum cleaner — standard vacuums spread fibres)
• Heavy-duty plastic bags (at least 0.2 mm thick, ideally double-bagged)
• Duct tape or cable ties to seal bags
• Asbestos waste labels (required for disposal)

All of these items are available from Bunnings or Mitre 10.

Step-by-Step Wet-Wiping Method

1. Secure the Area

Keep other people and pets out of the area. Close windows and doors to prevent fibres spreading through the house via air movement. If outdoors, work on a still day where possible.

2. Put On Your PPE

Dress in your coveralls, gloves, respirator, and eye protection before approaching the broken material. Fit-check your P2 respirator by cupping your hands over it and breathing in — you should feel it pull tight to your face.

3. Dampen the Debris

Using your spray bottle or garden sprayer, thoroughly wet all broken pieces and the surrounding surface. The goal is to keep everything damp throughout the entire clean-up — never let it dry out. Re-spray as needed.

4. Carefully Pick Up Larger Pieces

Gently pick up larger broken pieces by hand (gloved) and place them directly into a heavy-duty plastic bag. Do not snap, break, or compress them further. Avoid any action that creates dust.

5. Wet-Wipe All Affected Surfaces

Using a damp disposable cloth, wipe all hard surfaces in the affected area — floors, window sills, tools, anything that may have collected dust or fragments. Work from the outside of the contaminated area inward. Use each cloth once, then bag it immediately. Re-wet the surface and repeat until no visible residue remains.

6. Bag and Seal All Waste

Place all debris, cloths, and disposable PPE (coveralls, gloves) into the heavy-duty plastic bag. Double-bag it, seal tightly with duct tape, and label it clearly as asbestos waste. Your P2 respirator can also be bagged and disposed of as asbestos waste.

7. Clean Yourself

Wash your hands and face thoroughly with soap and water. Shower and change clothes before moving to other areas of the house.

Disposing of Asbestos Waste in NZ

Asbestos waste cannot go in your general rubbish or recycling. Contact your local council to find an approved disposal facility — most regional councils have a designated drop-off point or can direct you to a licensed landfill that accepts asbestos waste. Some councils require waste to be pre-booked. Check MBIE Building Performance for general guidance, and always confirm requirements with your local council.

What NOT to Do

• ❌ Do not use a household vacuum — it will spread fibres through the exhaust
• ❌ Do not dry-sweep or use compressed air
• ❌ Do not use a high-pressure hose — this aerosolises fibres
• ❌ Do not place asbestos waste in your kerbside bin
• ❌ Do not sand, grind, or cut any remaining asbestos cement

When to Call a Professional

Wet-wiping after a minor accidental breakage is something a careful homeowner can manage, but there are situations where you must engage a licensed asbestos removalist:

• More than one sheet or panel is broken or disturbed
• The material is friable (crumbly, not hard bonded cement)
• The area affected is larger than approximately 10 m²
• The work is in a rental property (additional obligations under health and safety law apply — see WorkSafe NZ)
• You are undertaking planned renovation or demolition work
• Anyone in the household has a respiratory condition
• You feel unsure at any point

Under the Health and Safety at Work (Asbestos) Regulations 2016, Class A asbestos removal (friable asbestos) must always be carried out by a licensed removalist. Class B (bonded, non-friable) removal over certain quantities also requires a licensed operator. WorkSafe NZ outlines these licensing requirements in detail.

You can find qualified, licensed asbestos removal specialists in your area on tradedirectory.co.nz.

Sources & Further Reading

• WorkSafe NZ – Asbestos guidance
• MBIE Building Performance – Building and asbestos
• BRANZ – Asbestos in homes
• Tenancy Services – Healthy Homes Standards
• Standards NZ