Tile Spacing Guide

The Complete Guide to Tile Spacing

Tile spacing — the gap between tiles filled with grout — might seem like a minor detail, but it has a significant impact on the appearance, durability, and waterproofing of your tiled surface. This guide covers everything you need to know about choosing the right grout width and spacer size.

Recommended Grout Widths by Tile Type

Why Grout Joints Are Necessary

Even if you prefer a seamless look, grout joints serve critical structural purposes:

Movement absorption — Tiles expand and contract with temperature changes. Without joints, this movement would crack the tiles or pop them off the substrate. A flexible grout joint absorbs this movement.

Waterproofing — In wet areas, grout (especially epoxy grout) creates a water barrier between tiles. Butted tiles with no joint allow water to seep through to the substrate.

Tolerance compensation — No tile is perfectly identical. Even rectified tiles have manufacturing tolerances of ±0.5mm. Grout joints compensate for these tiny size variations.

Aesthetic definition — Grout lines define the tile pattern and create visual rhythm. Without them, even beautiful tiles can look like a featureless slab.

Spacer Types Explained

Cross spacers are placed at the intersection of four tiles. They sit flat and maintain equal gaps in both directions. Remove them before grouting (or push them below the surface if they fit below grout depth).

T-spacers are essential for offset patterns (brick bond) where three tiles meet at a junction instead of four. The T sits flush at the offset joint.

Levelling systems (also called lippage control systems) use clips inserted under tiles and wedges that lock the clips tight. They ensure adjacent tiles are perfectly flush — critical for large-format tiles where even 1mm of lippage is visible and a tripping hazard.

Grout Width and Visual Impact

The width of your grout lines dramatically changes the appearance of a tiled surface:

Narrow joints (1.5-2mm):

• Near-seamless, contemporary appearance
• Best with rectified tiles and matching grout colour
• Shows every alignment imperfection — requires skilled installation
• Harder to fill consistently

Standard joints (3mm):

• The most common width for residential tiling
• Good balance of aesthetics and practicality
• Forgiving of minor tile size variations
• Easy to grout evenly

Wide joints (5-8mm):

• Rustic, traditional, or Mediterranean character
• Essential for handmade and natural stone tiles
• Very forgiving of irregular tile shapes
• More grout means more maintenance (sealing, cleaning)

Grout Types and When to Use Them

Cementitious grout is the traditional choice and the most affordable. It must be sealed in wet areas and resealed every 1-2 years. Use unsanded for joints under 3mm (sand scratches polished tiles) and sanded for wider joints.

Epoxy grout is waterproof, stain-proof, and mould-resistant without sealing. It's the best choice for bathrooms, kitchens, and anywhere that sees water or spills. The trade-off is higher cost and a shorter working time — it sets faster, so you must work in small sections.

Spacing Rules for Specific Areas

Shower walls and floors:

• Minimum 3mm joints with epoxy or polymer-modified grout
• Use silicone sealant (not grout) in all inside corners and where tiles meet the shower tray

Kitchen backsplash:

• 2-3mm joints for a clean, easy-to-wipe surface
• Epoxy grout behind the stove to resist grease staining

Outdoor areas / balconies:

• Minimum 5mm joints with flexible grout
• Tiles and grout must handle freeze-thaw cycles — use frost-proof materials

Heated floors:

• Minimum 3mm joints with flexible (polymer-modified) grout
• The heating element causes more expansion than unheated floors

How to Achieve Perfect Spacing

1. Start with a dry layout — Lay tiles without adhesive first to plan your spacing and identify problem areas.
2. Snap chalk lines — Mark reference lines on the substrate to keep rows straight.
3. Use spacers religiously — Place a spacer at every joint intersection, even if your eye says it's straight. Eyes deceive; spacers don't.
4. Check with a straightedge — Verify alignment every 3-4 rows. Small errors compound quickly.
5. Use a levelling system for large tiles — Any tile over 40cm should use clips and wedges to prevent lippage.
6. Remove spacers before grouting — Pull spacers out after the adhesive sets. Spacers left in the joint create weak points and colour variation in the grout.