Wet-scraping asbestos floor adhesive yourself is not legal in New Zealand if the material contains asbestos — and in most homes built before the mid-1980s, there's a very real chance it does. This is classified as restricted asbestos removal work under the Health and Safety at Work (Asbestos) Regulations 2016, meaning it must be carried out by a licensed professional. Here's what you need to understand before you pick up a scraper.
Why Old Floor Adhesive Is a Concern
Black bitumen-based adhesive (often called "black mastic" or "cutback adhesive") was widely used under vinyl tiles and sheet flooring in New Zealand homes from the 1940s through to the early 1980s. Many of these products contained chrysotile (white) asbestos as a binding agent. The adhesive itself can look perfectly ordinary — there's no way to tell by eye whether it contains asbestos.
If your home was built or renovated before 1990, you should assume the adhesive may contain asbestos until proven otherwise by laboratory testing.
What the Law Says in New Zealand
Under the Health and Safety at Work (Asbestos) Regulations 2016, asbestos removal work is split into two classes:
- Class A removal — friable asbestos or non-friable asbestos that is likely to become friable during removal. This requires a Class A licensed removalist.
- Class B removal — non-friable asbestos in good condition, removed in a way that does not make it friable. This requires a Class B licensed removalist.
Wet-scraping adhesive is specifically problematic because the scraping action — even when wet — can disturb and release asbestos fibres into the air. WorkSafe NZ considers this type of work to fall under Class A removal in most circumstances, because the mechanical action makes the material friable.
Homeowners are not exempt from these rules. Even on your own property, you cannot legally perform Class A or Class B asbestos removal work without the appropriate licence.
What About the "2 Square Metre Rule"?
You may have heard that homeowners can remove small amounts of non-friable asbestos themselves. Under the regulations, there is a provision allowing unlicensed removal of non-friable asbestos below a certain area threshold in certain circumstances — confirm the current threshold and conditions with WorkSafe NZ — but this does not apply to floor adhesive that will be scraped or disturbed. Once you scrape it, you risk making it friable, which moves it into Class A territory regardless of the area involved. Always confirm the current rules with WorkSafe NZ or a licensed asbestos assessor before proceeding.
Get the Adhesive Tested First
Before any work begins, the smart first step is to have a sample tested by an accredited laboratory. A licensed asbestos assessor can take samples safely and send them for analysis. If the result comes back negative for asbestos, you're free to proceed with normal floor preparation. If it's positive, you'll need a licensed removalist.
Testing is relatively affordable and gives you certainty — far cheaper than the health consequences of asbestos exposure or the legal penalties for unlicensed removal.
Safe Options for Homeowners
If asbestos is confirmed in the adhesive, here are your practical options:
| Option | What It Involves | Notes |
|---|---|---|
| Licensed removal | Class A removalist strips and disposes of adhesive | Safest; legally compliant |
| Encapsulation / overlay | New flooring laid directly over existing adhesive | Must be structurally sound; check with your flooring installer |
| Grinding with controls | Specialist grinding with H-class vacuum | Must be done by licensed professional |
Encapsulation (covering the adhesive rather than removing it) is often the most practical and cost-effective solution for homeowners. Many modern flooring products — including floating floors and new vinyl — can be installed over a well-bonded, flat adhesive layer, effectively sealing it in place. Discuss this option with your flooring installer and an asbestos assessor.
Health Risks You Cannot Ignore
Asbestos fibres are invisible to the naked eye. When inhaled, they can cause mesothelioma, asbestosis, and lung cancer — diseases that may not appear for 20–40 years after exposure. There is no safe level of asbestos exposure. Wetting the adhesive reduces (but does not eliminate) fibre release during scraping, which is why even "wet" methods are still regulated.
Protecting yourself with a standard dust mask is not sufficient — you would need a properly fitted P2 or P3 respirator at minimum, and even then, unlicensed removal remains illegal for this type of work.
When to Call a Professional
You should contact a licensed asbestos removalist if:
- Your home was built or renovated before 1990 and has old vinyl flooring or tiles
- Testing confirms asbestos in the adhesive
- You are planning any work that involves scraping, grinding, or sanding the old adhesive
- You are unsure whether the material contains asbestos
A licensed asbestos assessor can inspect the area, arrange testing, and provide a clearance certificate once removal is complete. You can find qualified asbestos removal specialists in your area at tradedirectory.co.nz.
For building consent questions related to floor replacement, check with your local council. Many straightforward flooring replacements fall under Schedule 1 exemptions of the Building Act 2004, but always confirm with your council before starting work — especially if structural elements are involved. See MBIE Building Performance for guidance.
Site Safe
Registered Master Builder
SiteWise
Tōtika Prequalified
ISO 45001
