Tiling a laundry trough splashback is one of the more satisfying DIY tiling jobs — the area is small, the cuts are usually straightforward, and the result makes a real difference to how tidy and waterproof your laundry looks. With good preparation and the right materials, most handy homeowners can achieve a neat, professional-looking finish.
What You'll Need
Gather your tools and materials before you start:
- Wall tiles (ceramic or porcelain — allow 10–15% extra for cuts and breakages)
- Waterproof tile adhesive suitable for wet areas (e.g. a ready-mixed or powder adhesive from Ardex or Mapei)
- Waterproof grout (unsanded for joints under 3 mm, sanded for wider joints)
- Tile spacers (2–3 mm is common for splashbacks)
- Notched trowel (check the adhesive manufacturer's recommendation for notch size)
- Tile cutter or angle grinder with a diamond blade
- Spirit level and pencil
- Grout float and sponge
- Silicone sealant — neutral-cure, mould-resistant, in a matching colour
- Painter's tape
Step 1 — Prepare the Surface
Good preparation is the single most important factor in a neat, lasting result.
- Check the substrate. Laundry walls are often lined with GIB standard plasterboard. In a wet area like a laundry splashback, you should ideally be tiling onto GIB Aqualine (moisture-resistant plasterboard) or a cement-based tile backer board. Standard plasterboard can be used if it is sound, dry, and will be fully protected by tiles and waterproof grout, but check with your tile adhesive manufacturer.
- Clean the wall. Remove any paint flakes, grease, dust, or soap residue. Wipe down with a damp cloth and allow to dry fully.
- Fill any holes or cracks and sand smooth.
- Apply a waterproofing membrane around the trough area if required. In NZ, MBIE Building Performance guidance and MBIE Building Performance guidance recommends waterproofing in wet areas — check your adhesive and membrane manufacturer's instructions.
Step 2 — Plan Your Layout
Before mixing any adhesive, dry-lay your tiles on a flat surface to plan the pattern.
- Find the centre point of the splashback area and work outward so any cut tiles are equal on both sides — this is what gives a professional, symmetrical look.
- Use a spirit level to draw a horizontal guideline at the height of your first row of tiles.
- Aim to avoid very thin slivers of tile at the edges; if a cut tile would be less than half a tile wide, shift your layout by half a tile.
- Mark any tap or pipe penetrations carefully — these cuts need to be measured twice.
Step 3 — Apply Adhesive and Set Tiles
- Mix or prepare your adhesive according to the manufacturer's instructions. Products from Ardex and Mapei include clear mixing ratios on the packaging.
- Apply adhesive to the wall (not the tile) using the notched trowel held at a consistent 45-degree angle to create even ridges.
- Work in small sections — roughly 0.5 m² at a time — so the adhesive doesn't skin over before you place tiles.
- Press each tile firmly with a slight twisting motion to collapse the ridges and achieve full coverage.
- Insert tile spacers at each corner as you go.
- Check frequently with your spirit level — adjust while the adhesive is still workable.
- Allow the adhesive to cure fully before grouting (usually 24 hours, but check the product data sheet).
Step 4 — Cut Tiles Neatly
- A manual tile scorer and snap cutter works well for straight cuts on ceramic tiles.
- For porcelain tiles or curved cuts around pipes, use an angle grinder with a diamond blade — wear safety glasses and a dust mask, and cut outside or in a well-ventilated area. See WorkSafe NZ for guidance on silica dust safety when cutting tiles.
- Smooth cut edges with a tile file or rubbing stone before fixing.
Step 5 — Grout and Seal
- Remove spacers once adhesive has cured.
- Mix grout to a smooth, peanut-butter consistency and apply with a grout float held at 45 degrees, working diagonally across the joints.
- Remove excess grout with a damp sponge before it hardens, rinsing the sponge frequently.
- Allow grout to cure (typically 24 hours), then buff off any haze with a dry cloth.
- Apply neutral-cure silicone sealant (not grout) at all internal corners and along the joint where tiles meet the trough. This flexible joint accommodates movement and prevents water ingress — a critical detail in any wet area.
Step 6 — Finishing Touches
- Use tile trim or edge tiles (such as bullnose or pencil trim) to finish any exposed tile edges neatly.
- Seal the grout with a grout sealer after full cure if using a cement-based grout — this helps resist mould and staining in the damp laundry environment.
When to Call a Professional
Tiling itself is not restricted work in NZ, so homeowners can legally tile their own splashback. However, there are important exceptions:
- Plumbing connections — moving or modifying tap connections, waste pipes, or the trough itself is restricted work under the Plumbers, Gasfitters and Drainlayers Act. This must be done by a licensed tradesperson registered with the Plumbers Gasfitters & Drainlayers Board.
- Electrical work — any changes to power points near the laundry trough must be carried out by a registered electrician licensed with the Electrical Workers Registration Board.
- If your substrate is damaged, mouldy, or you're unsure about waterproofing requirements, it's worth getting a professional tiler to assess the job first. You can find qualified local tilers on tradedirectory.co.nz.
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