Removing old paint from native timber floorboards is very achievable as a DIY project, but it requires the right equipment, patience, and a healthy respect for the timber underneath. Native species like rimu, kauri, matai, and heart pine are irreplaceable, so rushing the job or using the wrong technique can cause permanent damage.
Check for Lead Paint First
Before you do anything else, find out whether the paint contains lead. Homes built or painted before 1980 are likely to have lead-based paint on their floors. Lead dust is a serious health hazard, particularly for children and pregnant women.
Purchase an inexpensive lead test swab from a hardware store (available at Bunnings or Mitre 10) or hire a professional to test for you. If lead is present:
- Wear a P2 respirator (not just a dust mask), disposable coveralls, and gloves.
- Seal off the room with plastic sheeting to contain dust.
- Wet-sand or use a chemical stripper rather than dry sanding where possible to minimise airborne dust.
- Dispose of waste according to your local council's hazardous waste guidelines.
- Consider engaging a professional floor sander experienced in lead paint removal.
For more guidance, refer to WorkSafe NZ on working safely with lead paint.
Gather Your Equipment
For most painted floors, drum sanding is the most effective removal method. You'll need:
- Drum sander (hire from most tool hire shops or Mitre 10)
- Edge sander for skirting board areas
- Detail sander or hand scraper for corners
- Sandpaper in coarse (24–40 grit), medium (60 grit), and fine (80–100 grit) grades
- P2 respirator, safety glasses, and hearing protection
- Vacuum with a fine-dust filter
- Tack cloths
Alternatively, chemical paint strippers can be used before sanding to soften thick paint layers and reduce dust. Look for low-VOC or water-based strippers where possible. Always follow the manufacturer's instructions and ventilate the room well.
Heat guns can also help lift stubborn paint, but use them with extreme caution on native timber — excessive heat can scorch or crack the wood, and should never be used if lead paint is suspected, as it volatilises lead fumes.
The Sanding Process Step by Step
1. Prepare the Room
Remove all furniture, curtains, and rugs. Seal doorways with plastic sheeting to stop dust spreading through the house. Check every floorboard for protruding nails and punch them at least 3 mm below the surface — a nail will tear sandpaper and can be thrown dangerously by a drum sander.
2. Start with Coarse Grit
Begin with 24 or 36 grit paper on the drum sander. Work at a slight diagonal (about 15–20°) to the boards on the first pass — this cuts through paint faster. Keep the sander moving at all times; stopping while the drum is spinning will gouge the timber.
3. Sand with the Grain
Once the bulk of the paint is removed, switch to sanding along the length of the boards. Progress through medium (60 grit) and then fine (80–100 grit) to smooth the surface and remove scratch marks from earlier passes.
4. Edge and Detail Work
Use the edge sander around the perimeter, again progressing through grits. For tight corners and around door architraves, use a detail sander, a sharp hand scraper, or careful hand-sanding.
5. Vacuum and Tack
Thoroughly vacuum the entire floor and wipe down with tack cloths before applying any finish. Dust left on the surface will ruin your finish coat.
Choosing a Finish for Native Timber
Once bare timber is revealed, you have several finishing options suited to NZ conditions:
| Finish Type | Appearance | Durability | DIY Friendly? |
|---|---|---|---|
| Penetrating oil | Natural, low sheen | Moderate | Yes |
| Hardwax oil | Natural, satin | Good | Yes |
| Water-based polyurethane | Clear, satin–gloss | Very good | Yes |
| Oil-based polyurethane | Amber tone, gloss | Excellent | Moderate |
| Two-part commercial finish | High gloss | Excellent | Harder — fumes |
For rimu and kauri in particular, many homeowners prefer a penetrating oil or hardwax oil to preserve the natural warmth of the timber. Ask your local Resene or Wattyl store for advice on products suited to native species — staff can recommend appropriate primers and sealers too.
Always apply finish in a well-ventilated space and follow the manufacturer's recoat times carefully.
A Note on NZ Native Timber
Kauri in particular is a protected species — the timber in your floor is likely recycled from old-growth trees and cannot be replaced. Take extra care with coarse grits on kauri, as it is relatively soft and can be sanded unevenly. If you're unsure about the species or condition of your boards, consult a professional floor sander before proceeding. BRANZ has useful guidance on the care and maintenance of older NZ homes and their materials.
When to Call a Professional
Consider hiring a qualified floor sanding professional if:
- Lead paint is confirmed and you're not confident managing the hazard safely.
- The boards are thin, cupped, or in poor condition — over-sanding can make them too thin to be structurally sound.
- You're dealing with kauri or another delicate native species and want to preserve maximum timber thickness.
- The floor area is large and you want a consistently high-quality result.
A professional floor sander will have commercial-grade equipment, experience with native timbers, and the right dust containment systems. You can find qualified local floor sanders on tradedirectory.co.nz.
