Water and laminate flooring don't mix well — once moisture gets beneath the surface, planks can swell, buckle, or delaminate. The good news is that if you catch the damage early and it's limited to a few planks, this is a very manageable DIY repair. Here's how to tackle it the right way.
Step 1: Assess the Extent of the Damage
Before you grab any tools, take time to understand how far the damage has spread. Press down on surrounding planks and listen for a hollow or spongy feel — this can indicate moisture has wicked further than it appears. Check the subfloor beneath as well, because wet particleboard or plywood subfloors can harbour mould and will need to dry out (or be repaired) before new flooring goes down.
If the damaged area is larger than roughly 1–2 square metres, or if you suspect mould growth, it's worth getting a professional assessment. BRANZ has useful guidance on moisture management in NZ homes.
Step 2: Identify Your Flooring System
Most modern laminate uses a click-lock (floating floor) system, which makes plank replacement much easier than glued-down installations. Check whether your floor:
- Has a matching product still available (check the brand, colour code, and batch number — often printed on leftover planks or the original packaging)
- Is a floating floor or glued directly to the subfloor
- Has underlay beneath it (most NZ installations do)
If you can't find matching planks, try Bunnings or Mitre 10 — both stock a wide range of laminate options. Bring a sample plank to match thickness and finish as closely as possible.
Step 3: Gather Your Tools and Materials
You'll need:
| Item | Purpose |
|---|---|
| Replacement laminate planks | Like-for-like swap |
| Pull bar and tapping block | Clicking planks together |
| Pry bar and hammer | Removing damaged planks |
| Utility knife | Cutting underlay |
| Moisture meter | Checking subfloor dryness |
| Fans or dehumidifier | Drying out the subfloor |
| Safety glasses and gloves | Personal protection |
A moisture meter is particularly useful in NZ's variable climate — don't relay new flooring over a subfloor reading above about 14–16% moisture content (check your flooring manufacturer's spec sheet for the exact threshold).
Step 4: Remove the Damaged Planks
For a floating click-lock floor, the cleanest method is to work back from the nearest wall:
- Remove the skirting board or scotia trim along the closest wall.
- Carefully unclick and lift planks row by row until you reach the damaged section.
- Set undamaged planks aside in order — you can relay them.
If the damaged planks are in the middle of the room and working back from a wall isn't practical, you can use a circular saw to cut out just the affected planks. Score along the joints carefully to avoid damaging neighbouring planks, then chisel out the cut section. This is trickier but avoids disturbing the whole floor.
Step 5: Dry and Prepare the Subfloor
This step is critical and often rushed. Allow the subfloor to dry thoroughly — this may take several days with good airflow and a dehumidifier running. NZ's humid conditions (especially in coastal or lower South Island areas) can slow this process considerably.
- Check for mould on the subfloor surface. If present, treat with an appropriate mould-kill product and allow to dry before proceeding.
- If the subfloor itself is swollen, soft, or structurally compromised, it will need repair or replacement before new flooring is installed.
- Replace any damaged underlay — don't reuse wet or compressed underlay.
Step 6: Install the Replacement Planks
Once the subfloor is dry and sound:
- Lay new underlay over the repaired area if needed, taping joins.
- Click the replacement planks into position, working in the same direction as the existing floor.
- Use a tapping block and pull bar to seat planks firmly without damaging the locking profile.
- Refit skirting or scotia trim, leaving the correct expansion gap around the perimeter (typically 8–12 mm — check your product's installation guide).
Expansion gaps are important under the NZ Building Code to allow for seasonal movement, particularly in homes with underfloor heating or significant temperature variation.
Step 7: Address the Source of the Water
Replacing planks won't help if the source of moisture isn't fixed. Common culprits in NZ homes include:
- Leaking appliances (dishwashers, washing machines, fridges with water dispensers)
- Plumbing leaks under sinks or from pipe joints
- Condensation from poor subfloor ventilation
- Rising damp in older homes without a proper vapour barrier
For plumbing-related leaks, repairs to water supply pipes, drain connections, and sanitary fixtures are restricted work under NZ law and must be carried out by a licensed plumber registered with the Plumbers, Gasfitters and Drainlayers Board. Don't attempt these repairs yourself.
When to Call a Professional
Call a qualified flooring installer or builder if:
- The damaged area is large or the subfloor is structurally compromised
- You find significant mould growth (which may require specialist remediation)
- The water source is a plumbing or drainage issue
- You're unsure whether your floor requires a building consent for repair work (check with your local council)
- You simply want the job done right the first time
You can find experienced local flooring installers and builders on tradedirectory.co.nz.
