Removing old fibreglass batts is a job many Kiwi homeowners tackle themselves, but it pays to do it safely. Fibreglass insulation contains tiny glass fibres that can irritate your skin, eyes, and respiratory system if you're not properly protected. With the right gear and a methodical approach, you can remove old batts without putting your health at risk.
Why Fibreglass Batts Need Careful Handling
Fibreglass batts are made from spun glass fibres bound together with a resin binder. When disturbed — especially older batts that have become brittle and dusty — these fine fibres become airborne. Breathing them in can irritate your airways, and skin contact causes itching and redness. While fibreglass is not classified as a known carcinogen in the same way as asbestos, prolonged or repeated exposure without protection is not something you want to risk.
Older batts may also be contaminated with dust, rodent droppings, or mould, adding further health concerns. If your home was built before the 1980s, it's also worth checking whether any other insulation materials — particularly loose-fill or pipe lagging — could contain asbestos before you start work. If in doubt, have a sample tested by a professional before disturbing anything. WorkSafe NZ has clear guidance on identifying and managing asbestos safely.
Essential PPE Before You Start
Never begin removing fibreglass batts without the following personal protective equipment (PPE):
- P2-rated respirator or dust mask — a basic paper dust mask is not sufficient; you need a half-face respirator with P2 (particulate) filters
- Safety goggles — close-fitting, not open-sided glasses
- Disposable coveralls (Tyvek-style) — long sleeves and full leg coverage to prevent skin contact
- Nitrile or rubber gloves — fibreglass fibres can penetrate thin latex gloves
- Old work boots you can clean or cover with disposable boot covers
All of this PPE is readily available at Bunnings or Mitre 10.
Step-by-Step Safe Removal Process
1. Prepare the Work Area
Before you start, ventilate the space as much as possible — open any subfloor vents or roof space hatches. If you're working in a ceiling space, lay a board or two across the joists so you're not balancing on framing. Keep children and pets well away from the work area.
2. Minimise Fibre Release
Handle batts gently and slowly. Avoid shaking, tearing, or compressing them unnecessarily, as this releases more fibres into the air. Where possible, roll or fold batts carefully rather than crumpling them.
3. Bag as You Go
Place batts directly into heavy-duty plastic bags (heavy-duty plastic bags) as you remove them. Double-bagging is good practice. Seal each bag securely with tape before moving it. Don't overfill bags — keep them manageable to avoid tearing.
4. Work Methodically
Work from the far end of the space back towards the exit so you're not crawling over already-disturbed areas. In a subfloor, use a head torch and take regular breaks in fresh air.
5. Clean Up Carefully
Once the batts are removed, use a HEPA-filter vacuum to clean up any loose fibres and dust — a standard household vacuum will simply blow fine particles back into the air. Wipe down surfaces with a damp cloth rather than dry sweeping.
6. Dispose of Batts Correctly
Fibreglass insulation is classified as general construction waste in most NZ regions and can go to a transfer station or landfill, but always check with your local council for specific requirements. Keep bags sealed and labelled clearly. Do not put loose batts in your kerbside recycling bin.
7. After the Job
Remove your coveralls carefully, turning them inside out to trap fibres. Shower promptly and wash your work clothes separately from household laundry. Avoid rubbing your eyes or skin — rinse with cool water if irritation occurs.
Working in Subfloors vs Ceiling Spaces
| Location | Key Extra Considerations |
|---|---|
| Ceiling/attic space | Heat build-up; limited headroom; risk of stepping through gib board |
| Subfloor | Confined space; damp or mould possible; check for rodent activity |
In both cases, never work alone — have someone nearby who knows where you are and can assist if needed.
NZ Building Code and Replacement Insulation
If you're removing old batts to replace them, be aware that the NZ Building Code sets minimum insulation requirements (clause H1 — Energy Efficiency). Requirements vary by climate zone across New Zealand. Replacement insulation work in existing homes generally doesn't require a building consent, but it's always worth confirming with your local council, as rules can vary. BRANZ is a great resource for understanding best-practice insulation standards.
If your home is a rental property, replacement insulation must also meet the Healthy Homes Standards — check the requirements at Tenancy Services.
When to Call a Professional
Consider hiring a qualified insulation installer if:
- You suspect asbestos may be present anywhere in the building — this is restricted work and must be handled by a licensed asbestos removalist
- The space is very confined, poorly ventilated, or structurally unsafe to enter
- There is significant mould or rodent contamination in the insulation
- You're unsure about the type of insulation material you're dealing with
- You simply don't have the right PPE or feel uncomfortable doing the work
A professional insulation installer will have the right equipment, training, and disposal arrangements to do the job safely and efficiently. You can find qualified local insulation installers on tradedirectory.co.nz.
