A recessed shower niche is one of those upgrades that looks great and earns its keep every single day — no more shampoo bottles balanced on the edge of the bath. Done properly, a tiled niche is watertight, durable, and adds real value to your bathroom. Done poorly, it becomes a source of leaks and mould behind your walls. This guide walks you through how to plan and build one the right way, with NZ conditions and the Building Code in mind.
Planning Your Niche: Size, Location, and Framing
Before you pick up a tile saw, spend time on planning. The most common niche size is roughly 300 mm tall × 600 mm wide × 100–120 mm deep, but your dimensions will be driven by your tile size — always design the niche so tiles fit with minimal cutting.
Location matters enormously. Avoid positioning a niche on an exterior wall if at all possible, as cutting into insulated framing creates thermal bridging and condensation risks. An internal wall shared with a cupboard or hallway is ideal. Also avoid placing the niche directly in the main spray zone of the showerhead — a slightly offset position reduces the amount of water hitting the back of the niche directly.
Check what's inside the wall before you cut: use a stud finder and inspect for pipes, wiring, or noggings. In timber-framed homes built to NZS 3604, studs are typically at 400 mm or 600 mm centres, so a 600 mm-wide niche will usually fit neatly between two studs with a nogging added top and bottom.
Framing the Niche Box
Once you've confirmed the cavity is clear, cut the lining and frame the niche opening with treated timber noggings. The box needs to be solid — any flex will eventually crack your tiles and grout. Add a slight slope to the niche floor (around 5–10 mm fall toward the shower) so water drains out rather than pooling. This is a small detail that makes a big difference long-term.
Waterproofing: The Most Critical Step
This is where many DIY niches fail. Under the NZ Building Code clause E3 (Internal Moisture), wet areas must be waterproofed to prevent moisture damage to the building structure. A shower niche is fully inside the wet zone, so every surface — back, sides, floor, and ceiling of the niche — must be waterproofed before tiling.
Line the niche box with a tile backer board such as GIB Aqualine or a cement-based board (e.g. Hardiebacker from James Hardie). Standard plasterboard is not suitable inside a shower, even if painted.
Apply a liquid membrane system over all niche surfaces and the surrounding wall area, paying special attention to internal corners. Products from Ardex, Mapei, or Sika are widely used by NZ tilers. Bed fibreglass reinforcing tape into the membrane at all corners and joints. Apply at least two coats, allowing each to cure fully per the manufacturer's instructions. Don't rush this step.
BRANZ research consistently shows that inadequate waterproofing is one of the leading causes of bathroom moisture damage in NZ homes — it's worth doing properly.
Choosing Your Tiles
For the niche interior, smaller tiles (mosaic, 100×100 mm, or subway-style) are often easier to work with and look great as a feature. A contrasting tile inside the niche against the main shower tile is a popular design choice. Whatever you choose, make sure tiles are rated for wet area use.
Use a white or grey flexible adhesive rated for wet areas — standard wall tile adhesive is not suitable in a shower. Flexible adhesives from Ardex, Mapei, or Sika accommodate the slight movement that occurs in a tiled shower over time.
Tiling the Niche
Tile the back wall of the niche first, then the sides, then the floor (with your pre-built slope maintained), and finally the ceiling. The front edge (the reveal) is tiled last and is often finished with a pencil liner, bullnose tile, or metal trim for a clean edge.
Keep grout joints consistent with the rest of your shower. Use a flexible, waterproof grout — epoxy grout is highly durable and stain-resistant, though it requires more skill to apply. Standard cement grout must be sealed after curing.
Seal all internal corners of the niche with silicone sealant rather than grout. Grout cracks at movement joints; silicone flexes. Use a mould-resistant silicone in a colour matched to your grout.
Grouting, Sealing, and Curing
Allow tile adhesive to cure fully before grouting (check the product datasheet — typically 24 hours minimum). After grouting, allow a further cure period before applying silicone. Once everything is cured, apply a penetrating tile and grout sealer to cement-based grout. Allow the shower to cure for the full period recommended by your waterproofing membrane manufacturer before first use — this is often 7 days.
When to Call a Professional
Building a shower niche involves restricted building work if it affects the weathertightness or structure of your home — in that case, you'll need a Licensed Building Practitioner (LBP). Even where it's not technically restricted, waterproofing a wet area is a skill-dependent task: a failed membrane can cause thousands of dollars of hidden damage.
If your niche project involves moving or adding plumbing, that work must be carried out by a registered plumber licensed through the Plumbers, Gasfitters and Drainlayers Board (PGDB). Similarly, any electrical work (such as adding lighting inside the niche) must be done by a registered electrician — see the Electrical Workers Registration Board (EWRB) for what's restricted.
If you're not confident with any stage of this project — especially the waterproofing — it's well worth engaging a qualified local tiler. You can find experienced tilers in your area on tradedirectory.co.nz.