Tile spacers are one of those small details that make a big difference to the finished look of a tiling job. Choose too narrow a joint and your tiles may crack as the substrate moves; go too wide and the grout lines can overpower the design. This guide walks you through how to pick the right spacer size for common NZ tiling situations.
What Do Tile Spacers Actually Do?
Tile spacers are small plastic crosses (or T-shapes and wedges) placed between tiles during installation to keep grout joints consistent and even. Once the adhesive has cured, you remove them before grouting. A consistent joint width not only looks professional — it also allows the grout to do its job of accommodating minor movement in the substrate and preventing water ingress, which is especially important in wet areas covered by NZ Building Code clause E3.
Common Spacer Sizes and When to Use Them
Spacers are typically sold in sizes ranging from 1 mm through to 5 mm or more. Here's a general guide:
| Spacer Size | Best Used For |
|---|---|
| 1–1.5 mm | Small mosaic tiles, glass tiles, rectified porcelain |
| 2 mm | Wall tiles (standard ceramic), rectified floor tiles |
| 3 mm | Most floor tiles, general-purpose wall tiles |
| 4–5 mm | Larger format tiles (400 mm+), rustic or handmade tiles |
| 5 mm+ | Pavers, outdoor tiles, very large format tiles |
These are starting points — always check the tile manufacturer's recommendations, as some tiles (particularly handmade or natural stone) require wider joints to account for size variation.
Key Factors That Affect Your Choice
Tile Size and Format
As a general rule, larger tiles need wider grout joints. A large-format tile (say 600 mm × 600 mm or bigger) will have more variation in its dimensions and will flex more with the substrate, so a 3–5 mm joint is usually recommended. Small mosaic tiles on a mesh backing often look best with a 1–2 mm joint.
Rectified vs. Non-Rectified Tiles
Rectified tiles are precision-cut to exact dimensions after firing, so they can be laid with very tight joints (as small as 1–2 mm). Non-rectified tiles have slight size variations from the kiln process and generally need at least a 3 mm joint to hide those differences.
Floor vs. Wall
Floor tiles typically need a slightly wider joint than wall tiles because floors experience more movement and load. A 3 mm spacer is a solid all-round choice for most NZ floor tile installations. For walls, 2–3 mm is common, though a sleek, modern look with rectified tiles might call for 1.5–2 mm.
Indoor vs. Outdoor
Outdoor areas in New Zealand experience significant temperature swings, especially in regions like Canterbury or Central Otago. Wider joints (4 mm or more) give the grout room to accommodate thermal expansion and contraction. BRANZ guidance on exterior cladding and tiling highlights the importance of movement joints in exposed situations.
Wet Areas
In bathrooms, showers, and laundries — all regulated under NZ Building Code clause E3 (Internal Moisture) — consistent grout joints are critical for waterproofing. A joint that's too narrow can be difficult to grout properly, leaving gaps where water can penetrate. Aim for at least 2–3 mm in wet areas and use a quality waterproof grout.
Choosing the Right Grout to Match
Once you've settled on a spacer size, your grout choice needs to match. Most unsanded grouts are suitable for joints up to about 3 mm; sanded or epoxy grouts are better for wider joints as they resist shrinkage. Products from Ardex and Mapei are widely used by NZ tilers and are available at trade and retail outlets. Always read the product data sheet for the recommended joint width range.
Where to Buy Tile Spacers in NZ
Tile spacers are inexpensive and widely available. You'll find a good range at Mitre 10 and Bunnings, as well as specialist tile shops and PlaceMakers. As a guide, a bag of spacers for a standard bathroom project is a very modest cost — don't be tempted to skip them or reuse old ones, as worn spacers give inconsistent results.
Tips for Getting Even Joints
- Use wedge spacers for wall tiles — they're easier to adjust on a vertical surface than cross spacers.
- Remove spacers before the adhesive fully cures (usually within a few hours, depending on the product and temperature).
- Don't grout over spacers — always remove them first or you'll get an uneven finish.
- Check your layout with a dry run before applying adhesive, so you can adjust joint widths to avoid awkward cuts at edges.
- For large areas, use a tile levelling system alongside spacers to prevent lippage (where tile edges sit at different heights).
When to Call a Professional
While choosing and using tile spacers is well within a confident DIYer's ability, some aspects of tiling are best left to — or legally require — a qualified tradesperson:
- Waterproofing in wet areas must comply with NZ Building Code clause E3. Incorrect waterproofing can lead to costly structural damage and may void your home insurance.
- Tiling over underfloor heating requires careful adhesive and grout selection and should ideally be done by an experienced tiler.
- Large commercial or high-traffic floor projects benefit from professional substrate assessment and installation.
- If your project involves moving or installing plumbing fixtures, that work must be carried out by a licensed plumber registered with the Plumbers, Gasfitters and Drainlayers Board.
For peace of mind on bigger or more complex jobs, find a qualified local tiler on tradedirectory.co.nz.