Tiling a recessed shower niche without lippage is absolutely achievable as a DIY project, but it demands careful planning before a single tile goes up. The key is treating the niche as part of your overall tile layout from day one — not as an afterthought. Get the substrate flat, your adhesive consistent, and your tile sizes matched correctly, and you'll end up with a professional-looking result.
What Causes Lippage in a Shower Niche?
Lippage is the term for when the edge of one tile sits higher or lower than its neighbour, creating an uneven, trip-hazard-like surface. Around a niche, it's especially common because:
- The niche recess creates a step in the substrate plane
- Tiles wrapping into the niche meet tiles on the main wall at a corner
- Inconsistent adhesive bed thickness causes tiles to sit at different heights
- Mismatched tile thicknesses (e.g., field tiles vs. trim tiles) create unavoidable offsets
Understanding these causes helps you prevent them systematically.
Step 1 — Plan Your Layout Before You Build the Niche
Ideally, the niche position is decided before the substrate is installed. The niche height and width should be sized to suit whole or half tiles wherever possible, minimising awkward cuts at the edges.
- Dry-lay your tiles on the floor and measure the niche opening against your tile grid
- Aim for the niche shelf (the bottom horizontal surface) to align with a horizontal grout joint on the main wall
- The niche sides should ideally fall on vertical grout lines too
- Mark your tile layout lines on the wall with a spirit level and chalk line before mixing any adhesive
This planning step alone eliminates most lippage problems before they start.
Step 2 — Prepare a Flat, Waterproofed Substrate
In a shower, the substrate must comply with NZ Building Code clause E3 (internal moisture) and be properly waterproofed. Recessed niches are a high-risk area for moisture ingress — the shelf and back wall must be waterproofed just as thoroughly as the shower floor and walls.
- Use a tile-rated substrate such as GIB Aqualine or a cement board product inside the niche
- Apply a compatible liquid membrane (products from Ardex, Mapei, or Sika are widely used in NZ) to all niche surfaces, paying extra attention to corners and the shelf
- Allow the membrane to fully cure before tiling
- Check that the niche back wall is flush or within 3 mm of the plane you want your tiles to sit on — use a long straightedge across the main wall and into the niche to check
If the niche back is recessed further than your tile thickness plus adhesive bed can compensate for, you may need to build it out with a skim of tile adhesive or a render coat before waterproofing.
Step 3 — Choose the Right Adhesive and Apply It Consistently
For a wet area like a shower, use a polymer-modified, flexible tile adhesive rated for wet areas. Brands such as Ardex and Mapei offer suitable products widely available from Placemakers and Mitre 10.
- Use the back-buttering technique: apply adhesive to both the substrate and the back of each tile
- Use the correct notched trowel size for your tile format — larger tiles need a larger notch
- Maintain a consistent adhesive bed thickness across the main wall and inside the niche; this is the single biggest factor in preventing lippage
- Use tile levelling clips and wedges (available at Bunnings) — these are inexpensive and make a huge difference when tiling around a niche where tiles meet at corners
Step 4 — Tiling the Niche Itself
The order in which you tile the niche matters:
- Tile the back wall of the niche first, keeping it flush with your main wall tile plane
- Tile the two side walls next, using a small offcut or tile spacer to maintain the correct grout joint width at the back corners
- Tile the shelf (bottom) last, ensuring it has a slight fall (1–2°) toward the shower to drain water — this is especially important for Healthy Homes compliance in rental properties and general good practice everywhere
- Tile the top (soffit) of the niche if it is deep enough to require it
For the niche edges where they meet the main wall tiles, you have two main options:
| Option | Appearance | Difficulty |
|---|---|---|
| Schluter-style metal trim/edge profile | Clean, modern, hides cut edges | Moderate — must be set before tiling |
| Mitred tile corners | Seamless, premium look | Higher — requires a wet saw with mitre capability |
| Bullnose tiles | Traditional, rounded edge | Easy — if matching bullnose is available |
Metal edge profiles (available at Mitre 10 and Bunnings) are the most practical choice for most DIYers and help manage the transition between planes without lippage.
Step 5 — Grouting and Sealing
- Use a flexible, mould-resistant grout rated for wet areas
- Maintain consistent grout joint widths throughout — use spacers right up to the niche edges
- Apply silicone sealant (not grout) at all internal corners inside the niche and where the niche meets the main wall — this allows for movement and prevents cracking
- Seal natural stone or unglazed tiles with an appropriate penetrating sealer once grout has cured
When to Call a Professional
If the niche is being cut into an existing wall, or if you're unsure whether the existing waterproofing membrane is intact, it's worth calling a qualified tiler. Waterproofing failures in showers can cause serious structural damage and are expensive to remediate. You can find experienced local tilers on tradedirectory.co.nz.
Note that any work involving moving plumbing (e.g., relocating a shower valve or drain) is restricted work under the Plumbers, Gasfitters and Drainlayers Act and must be carried out by a licensed tradesperson registered with the PGDB.
For guidance on building consent requirements — for example, if the niche involves structural framing changes — check with your local council or visit MBIE Building Performance.
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