Scraping old putty from window frames might seem like a straightforward weekend job, but if your home was built before the mid-1980s, that putty could contain asbestos — and disturbing it yourself is both dangerous and, in most cases, illegal in New Zealand. The short answer is: no, it is not safe to scrape asbestos-containing putty yourself, and doing so could expose you, your family, and your neighbours to harmful fibres.
Why Window Putty May Contain Asbestos
Asbestos was widely used in New Zealand building materials right up until it was phased out in the mid-1980s. Window glazing putty was one of many products that sometimes contained chrysotile (white) asbestos as a filler and strengthening agent. Homes built or renovated before approximately 1985 are most likely to have asbestos-containing materials, including putty around single-glazed timber or steel-framed windows.
You cannot identify asbestos by sight alone. The only reliable way to confirm whether your putty contains asbestos is to have a sample tested by an accredited laboratory. A licensed asbestos assessor can take samples safely and arrange testing for you.
The Health Risks of Disturbing Asbestos Putty
When asbestos-containing materials are scraped, sanded, or broken apart, they release microscopic fibres into the air. These fibres can be inhaled and become permanently lodged in the lungs, potentially causing serious diseases including:
- Mesothelioma (an aggressive cancer of the lung lining)
- Asbestosis (scarring of the lung tissue)
- Lung cancer
These diseases can take 20–40 years to develop, which is why many people underestimate the risk. There is no known safe level of asbestos exposure. WorkSafe NZ provides detailed guidance on asbestos health risks and your rights as a homeowner or worker.
NZ Legal Requirements: What Is Restricted Work?
Under the Health and Safety at Work (Asbestos) Regulations 2016, asbestos removal work is tightly regulated in New Zealand. Here is a simplified breakdown:
| Type of Work | Who Can Do It |
|---|---|
| Friable asbestos removal (any amount) | Licensed Class A removalist only |
| Non-friable asbestos removal (≥10 m²) | Licensed Class A or B removalist |
| Non-friable asbestos removal (<10 m²) | Competent person (homeowner may qualify, but see below) |
| Asbestos assessment and air monitoring | Licensed asbestos assessor |
Window putty is generally considered non-friable when intact — meaning it does not crumble easily by hand. However, the act of scraping putty makes it friable, releasing fibres. This is a critical distinction: once you start scraping, you are generating friable asbestos dust, which pushes the work into higher-risk territory regardless of the area involved.
Even if the total area is under 10 m², the practical reality is that most homeowners do not have the training, equipment (including a P2 respirator, disposable coveralls, and proper containment), or waste disposal knowledge to do this work safely and legally. MBIE Building Performance and WorkSafe both strongly recommend engaging a licensed professional for any asbestos removal involving window putty.
What About DIY for Small Areas?
Some homeowners ask whether they can handle a small patch of putty themselves. While the regulations do allow a homeowner to remove small amounts of non-friable asbestos from their own home (not a rental property), the following conditions must all be met:
- The material must remain non-friable throughout removal (not crumbled or powdered)
- You must use appropriate PPE including a properly fitted P2 respirator — not a dust mask
- The waste must be double-bagged, labelled, and disposed of at an approved facility
- You must not put yourself or others at risk
In practice, scraping putty almost always creates dust and fragments, making truly non-friable removal very difficult. If in doubt, do not attempt it. The consequences of getting it wrong are severe and irreversible.
Getting the Work Done Safely
The safest and most legally sound approach is to:
- Have the putty tested by an accredited laboratory via a licensed asbestos assessor before any work begins.
- Engage a licensed asbestos removalist — Class A or B depending on the scope — to remove the putty safely.
- Obtain a clearance certificate from a licensed asbestos assessor once removal is complete, confirming the area is safe.
Asbestos removal does not typically require a building consent, but always confirm with your local council if other window work is involved, as window replacement can sometimes trigger consent requirements under the NZ Building Code.
When to Call a Professional
You should always call a licensed asbestos removal specialist if:
- Your home was built or renovated before 1985 and you suspect asbestos putty
- You are planning to replace or reglaze windows in an older home
- You have already disturbed the putty and are concerned about exposure (seek medical advice too)
- You are a landlord — under the Healthy Homes Standards, you have additional obligations to keep rental properties safe
You can find qualified, licensed asbestos removal specialists in your area right here on tradedirectory.co.nz.
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