Installing flooring under a fixed kitchen island is one of those jobs that looks straightforward until you realise the island is bolted down. The good news is there are a few solid approaches depending on your floor type, your island's construction, and how much disruption you're willing to take on. Here's what you need to know before you start.
Understand What You're Working With First
Before you pick up a tool, figure out two things: how the island is fixed, and what type of flooring you're installing.
Most kitchen islands are either:
- Bolted through the subfloor via brackets or toe-kick fixings
- Screwed directly into the subfloor through the base cabinet frame
- Plumbed or wired — meaning there may be a sink, dishwasher, or power outlet involved
If your island has plumbing or electrical connections, you'll need to factor in disconnection before moving it. Plumbing work on fixed connections is restricted work under NZ law and must be carried out by a licensed plumber registered with the Plumbers Gasfitters & Drainlayers Board. Similarly, any electrical disconnection or reconnection must be done by a registered electrician — check the Electrical Workers Registration Board for licensed tradespeople in your area.
Option 1: Remove the Island, Lay the Floor, Reinstall
This is the cleanest and most recommended approach, especially for rigid flooring like tile, vinyl plank (LVT), or engineered timber. It gives you a continuous, professional-looking floor with no awkward cuts or gaps.
Steps:
- Disconnect any plumbing or electrical (by licensed tradespeople if required).
- Unscrew or unbolt the island from the subfloor — keep all fixings safe.
- Slide or lift the island clear of the work area.
- Lay your flooring across the full area, including where the island will sit, following the manufacturer's installation instructions.
- For floating floors (click-lock LVT or engineered timber), leave the standard 10–12 mm expansion gap around the perimeter of the room, but you do NOT need to leave a gap around the island footprint — the island will sit on top of the floor, not be fixed through it (see Option 3 below for more on this).
- Reinstall the island on top of the new floor. If re-bolting through the floor, use appropriate fixings for your subfloor type and ensure the island is stable.
Option 2: Work Around the Island (Not Recommended for Most Floors)
If removing the island is genuinely not possible — say, it's a very large, heavy stone-topped unit with live plumbing — you can cut flooring to fit around it. This works reasonably well for sheet vinyl or tile, but creates visible seams and makes future removal harder.
- Measure the island footprint carefully and transfer it to your flooring material.
- Use a jigsaw for LVT or engineered timber, or a angle grinder with a tile blade for ceramic/porcelain tile.
- Ensure cut edges are tight to the island base so they won't lift or catch underfoot.
- Seal cut edges of sheet vinyl with a compatible edge sealant to prevent moisture ingress — important in a kitchen environment.
This approach is harder to execute neatly and can look patchy if the island is ever moved later.
Option 3: Floating Floors and Fixed Islands — A Key Consideration
This is where many DIYers run into trouble. Floating floors must be able to move freely — they expand and contract with temperature and humidity changes. If you bolt a heavy island through a floating floor, you pin it down and the floor can buckle or gap over time.
The correct approach for a floating floor is:
- Lay the floor continuously under the island footprint.
- Do not bolt through the floating floor to fix the island.
- Instead, fix the island to the subfloor using longer bolts or brackets that bypass the floating floor layer, or use a rigid-fixed floor type (tile, glued-down vinyl) if a bolted island is essential.
Check your flooring manufacturer's technical data sheet for guidance — brands like James Hardie (for fibre cement substrates) and adhesive suppliers like Ardex or Mapei publish detailed installation specs.
Subfloor Preparation
Whatever approach you take, the subfloor under the island area must be flat, dry, and structurally sound. In NZ kitchens — especially older homes — check for:
- Moisture from previous plumbing leaks (use a moisture meter; acceptable levels vary by product, but most manufacturers specify below levels specified by the product manufacturer — check the technical data sheet for your specific flooring product)
- Deflection — the subfloor should not flex underfoot; NZS 3604 sets structural standards for timber-framed floors
- Level — most flooring products require no more than 3 mm variation over 1.8 m
For advice on subfloor standards and moisture management, BRANZ is an excellent NZ-specific resource.
Building Consent — Do You Need One?
Flooring replacement is generally exempt from building consent under Schedule 1 of the Building Act. However, if you're moving the island's position and that involves relocating plumbing or electrical, those elements may require consent or at minimum a Certificate of Compliance from your licensed tradesperson. Always confirm with your local council if you're unsure — MBIE Building Performance has clear guidance on what work requires consent.
When to Call a Professional
Call a qualified tradesperson if:
- The island has plumbing or electrical connections that need disconnecting
- The island is extremely heavy or built-in and you're unsure how to remove it safely
- Your subfloor has moisture damage or structural issues that need remediation first
- You're installing tile over a large area and need precise levelling and waterproofing
A skilled flooring installer will also know how to handle the transition between the kitchen and adjoining rooms neatly. You can find qualified local flooring installers on tradedirectory.co.nz.
Sources & Further Reading
- BRANZ – Floor construction and subfloor guidance
- MBIE Building Performance – Building consent and Schedule 1 exemptions
- Plumbers Gasfitters & Drainlayers Board – Licensed plumbers
- Electrical Workers Registration Board – Licensed electricians
- Ardex NZ – Subfloor preparation products and specs
- Mapei NZ – Flooring adhesives and installation guides
