What Is the Correct Order to Tile a Shower: Walls or Floor First?

In most situations, the correct order is to tile the shower walls first, then the floor. This sequence protects your waterproofing membrane, keeps grout lines clean, and makes the whole job easier to manage. There are a few exceptions worth knowing about, which we'll cover below.

Why Tile Walls Before the Floor?

Tiling walls first is standard trade practice for several good reasons:

• Protects the floor tiles: Wall tile adhesive, grout, and offcuts will inevitably fall during the job. If the floor is already tiled, you risk chipping or staining your finished floor tiles.
• Cleaner grout joints: You can run wall tiles down to just above the floor level, then cut and fit floor tiles neatly underneath — giving you a tidy, controlled junction.
• Waterproofing integrity: In a NZ shower, the waterproofing membrane (required under the Building Code clause E3) is typically applied to the substrate before tiling. Tiling walls first means you're not disturbing a finished floor when working overhead.
• Easier layout: Setting out wall tiles from a level datum line is simpler when the floor is clear and accessible.

The Correct Step-by-Step Sequence

Here is the order a professional tiler follows for a typical NZ shower recess:

1. Prepare the substrate — Ensure walls and floor are structurally sound, clean, and flat. Shower walls are commonly lined with GIB Aqualine or a cement-based tile backer board.
2. Apply waterproofing membrane — This is a critical step. The entire shower floor and walls (to at least 1800 mm high, or as specified) must be waterproofed before any tiles go on. Check MBIE Building Performance guidance on wet area requirements.
3. Allow membrane to cure fully — Follow the manufacturer's cure times. Do not rush this step.
4. Set out and tile the walls — Start from a level horizontal line (use a laser level or spirit level). Work from the bottom up, leaving a small gap at the floor level for the floor tiles to slide under.
5. Grout the wall tiles — Complete wall grouting before moving to the floor.
6. Tile the floor — Cut floor tiles to fit neatly against the wall tiles. Ensure the floor tiles slope correctly toward the drain (typically a 1:100 fall minimum).
7. Grout the floor tiles.
8. Seal the junction — The corner where wall tiles meet floor tiles should be finished with a flexible silicone sealant, not grout. Grout is rigid and will crack at movement joints. Use a sanitary-grade silicone in a matching colour.

Choosing the Right Adhesive and Grout

For wet areas like showers, always use a flexible, waterproof tile adhesive rated for wet areas. Standard grey cement-based adhesives may not be suitable on their own. Brands like Ardex, Mapei, and Sika all offer wet-area tile adhesives and grouts available from trade suppliers and stores like Bunnings and Mitre 10.

Use a flexible grout (epoxy or polymer-modified) in wet areas for durability and mould resistance.

The One Exception: Large Format Floor Tiles

If you are using very large format floor tiles (600 mm × 600 mm or bigger) that need to be set first to establish a key reference point for the room layout, some tilers will set the floor tiles dry (ungrouted) first to confirm the layout, then tile the walls, and finally bed and grout the floor. This is less common in a standard shower but worth discussing with your tiler if you have a complex layout.

Waterproofing: Don't Skip This Step

In New Zealand, waterproofing a shower is not optional — it is required under the NZ Building Code (Clause E3: Internal Moisture). Failure to waterproof correctly is one of the most common causes of costly water damage in NZ homes. BRANZ research consistently identifies poor wet area waterproofing as a leading defect in residential construction.

If your shower is in a new build or a significant renovation, check with your local council whether a building consent is required. Minor like-for-like retiling may fall under Schedule 1 exemptions, but always confirm with your council — rules vary.

When to Call a Professional

Tiling a shower is a skilled job. Mistakes with waterproofing, falls to the drain, or grout joints can lead to leaks, mould, and expensive repairs. Consider hiring a qualified tiler if:

• You are not confident with waterproofing membrane application
• The shower involves complex cuts, niches, or large format tiles
• You are unsure about the correct floor fall to the drain
• The existing substrate needs repair or replacement

If your shower renovation involves moving or adding plumbing fixtures, that work must be carried out by a licensed plumber — it is restricted work under the Plumbers, Gasfitters and Drainlayers Board (PGDB). Similarly, any electrical work (such as adding a heated towel rail or exhaust fan) must be done by a registered electrician under the Electrical Workers Registration Board (EWRB).

You can find qualified, local tilers and other tradespeople on tradedirectory.co.nz.

Sources & Further Reading

• MBIE Building Performance — Wet Areas and Waterproofing
• BRANZ — Building Research
• GIB — Wet Area Wall Linings
• Ardex NZ — Tile Adhesives and Waterproofing
• Mapei NZ — Tile and Stone Installation Products
• Sika NZ — Construction Sealants and Adhesives