How Do I Test Old Floor Tiles for Asbestos Before Renovating?

If your home was built before the mid-1990s, there's a real chance your old floor tiles — or the adhesive beneath them — contain asbestos. The good news is that testing is straightforward, relatively affordable, and an essential step before any renovation that might disturb those tiles.

Why Old Floor Tiles Are a Concern

Asbestos was widely used in New Zealand building materials up until it was phased out through the late 1980s and early 1990s. Vinyl floor tiles, sheet vinyl backing, and the black mastic adhesive used to bond them were all common sources of asbestos-containing materials (ACMs). Tiles from this era often measured 225 mm × 225 mm or 300 mm × 300 mm and came in speckled or marbled patterns.

Undisturbed tiles in good condition are generally considered non-friable — meaning the asbestos fibres are bound within the material and pose a lower immediate risk. However, cutting, sanding, grinding, or breaking these tiles can release dangerous fibres into the air. Breathing in asbestos fibres can cause serious diseases including mesothelioma and asbestosis, so it's critical to test before you renovate.

WorkSafe NZ provides detailed guidance on asbestos risks and your legal obligations as a homeowner or person conducting a business.

How to Identify Suspect Tiles

Before testing, do a visual assessment:

• Age of the home: Built before 1990? Treat all resilient flooring as suspect.
• Tile size and appearance: Speckled 225 mm or 300 mm square tiles are a common indicator.
• Black adhesive: The dark, tar-like mastic glue under tiles is frequently asbestos-containing, even if the tiles themselves are not.
• Condition: Cracked, crumbling, or damaged tiles are higher risk and should not be touched until tested.

Visual inspection alone cannot confirm asbestos — only laboratory analysis can do that.

Your Two Testing Options

Option 1: Hire a Licensed Asbestos Assessor

The safest and most reliable approach is to engage a licensed asbestos assessor to take samples and arrange laboratory analysis. They know exactly where to sample, how to do it safely, and can provide a formal report — which may be required if you're selling your home or managing a rental property under the Healthy Homes standards.

Option 2: DIY Sampling for Lab Analysis

In New Zealand, homeowners are generally permitted to collect a small sample from their own home for testing, provided they follow safe work practices. This is not the same as removal — removal of more than 10 m² of non-friable asbestos material requires a licensed removalist under WorkSafe regulations.

If you choose to sample yourself, follow these steps carefully:

1. Gather your PPE: Wear a properly fitted P2 respirator (not a dust mask), disposable gloves, and old clothing you can bag and dispose of.
2. Wet the area: Lightly mist the tile with water mixed with a small amount of dish soap. This suppresses fibre release.
3. Take a small sample: Using a sharp knife or chisel, cut or chip a small piece (around 1–2 cm²) from the tile, including any adhesive beneath it. Work slowly and avoid creating dust.
4. Seal the sample: Place it immediately into a zip-lock bag, then into a second bag. Label it clearly.
5. Clean up: Wipe the area with a damp cloth, place all materials (gloves, cloth, clothing) into a sealed plastic bag for disposal.
6. Wash thoroughly: Wash your hands and face well after removing PPE.

Send the sealed sample to an IANZ-accredited laboratory for analysis. Several NZ labs offer asbestos identification testing; your local council or a licensed assessor can point you to accredited options. Results typically take a few business days and costs vary — as a rough guide, expect to pay somewhere in the range of $30–$100 per sample for laboratory analysis alone, though this can vary.

Understanding Your Results

The lab report will state whether asbestos was detected and, if so, the type (e.g., chrysotile, amosite). From here:

• No asbestos detected: You can proceed with renovation, though always confirm the adhesive was also tested.
• Asbestos confirmed: Do not disturb the tiles further. You'll need to decide whether to encapsulate (cover over) or remove the material — both options have rules attached.

Under MBIE Building Performance guidelines and the NZ Building Code, certain renovation work may also require a building consent. Always check with your local council before starting significant floor work.

Asbestos Removal Rules in New Zealand

This is where DIY has firm legal limits:

• Non-friable asbestos up to 10 m² may be removed by a competent homeowner following WorkSafe safe work practices — but this is still high-risk work.
• More than 10 m² of non-friable asbestos, or any friable asbestos, must be removed by a licensed asbestos removalist (Class A or Class B licence depending on the material).
• Disposal must follow your local council's requirements for hazardous waste.

Always check WorkSafe NZ for the current regulations before attempting any removal yourself.

When to Call a Professional

Call a licensed asbestos assessor or removalist if:

• The tiles are cracked, crumbling, or in poor condition
• The area to be disturbed is larger than a few square metres
• You're unsure about the extent of ACMs in the floor
• You're managing a rental property (landlords have specific obligations)
• You want a formal written report for insurance, sale, or council purposes

A qualified asbestos professional will carry the right equipment, training, and insurance. You can find licensed asbestos removal specialists in your area at tradedirectory.co.nz.

Sources & Further Reading

• WorkSafe NZ – Asbestos guidance
• MBIE Building Performance – NZ Building Code
• BRANZ – Building research and guidance
• Tenancy Services – Healthy Homes standards
• Standards NZ