How Do I Fix a Tile That Has Cracked Right Down the Middle?

A tile cracked right down the middle is one of the more satisfying DIY repairs you can tackle at home — provided you have a spare tile, the right tools, and a bit of patience. In most cases, the fix involves carefully removing the broken tile, cleaning up the substrate, and bedding in a new tile with fresh adhesive and grout. Here's how to do it properly.

Why Tiles Crack in the First Place

Before you repair the tile, it's worth understanding what caused the crack. Common culprits include:

• Point impact — something heavy dropped on it
• Movement in the substrate — the floor or wall flexing underneath
• Hollow or poorly bonded tile — inadequate adhesive coverage when first laid
• Thermal expansion — especially in outdoor or underfloor-heated areas

If you tap surrounding tiles with a coin or knuckle and hear a hollow sound, there may be a broader bonding problem. If multiple tiles are cracking or lifting, it's worth getting a professional tiler to assess the whole area before you start patching.

Tools and Materials You'll Need

• Angle grinder or oscillating multi-tool (for grout removal)
• Grout rake or carbide-tipped grout saw
• Cold chisel and hammer (or electric chisel/rotary hammer for larger tiles)
• Safety glasses, dust mask, and gloves
• Replacement tile (ideally from your original batch)
• Tile adhesive appropriate for your substrate (floor, wall, wet area)
• Grout matched to your existing colour
• Notched trowel
• Grout float and sponge
• Tile spacers

Safety note: Broken tiles have razor-sharp edges. Always wear heavy gloves when handling fragments, and safety glasses when chiselling or grinding. If you're working in a wet area like a shower, switch off the power to any nearby circuits at the switchboard before you start.

Step-by-Step: Removing the Cracked Tile

1. Remove the grout

Using a grout rake, oscillating tool, or angle grinder with a grout-removal blade, carefully remove the grout from all four joints around the cracked tile. Take your time — you don't want to chip the surrounding tiles.

2. Break out the tile

Score across the cracked tile with your angle grinder, then use a cold chisel and hammer to break it into smaller pieces and lever them out. Work from the centre outward. For large-format tiles, an electric chisel makes this much easier.

3. Clean the substrate

Scrape off all old adhesive from the substrate until you have a clean, flat surface. Any high spots will cause your new tile to sit proud. Check the substrate for damage — if it's a wet area and the substrate (e.g. GIB Aqualine or fibre-cement sheet) is soft or crumbling, it may need replacing before you re-tile.

Choosing the Right Adhesive

The adhesive you use matters. As a general guide:

Brands like Ardex, Mapei, and Sika all offer NZ-stocked adhesives suited to different situations. Read the product data sheet and follow the manufacturer's instructions — coverage, open time, and cure time all vary.

Important: In wet areas (showers, baths), the NZ Building Code clause E3 requires adequate waterproofing. If removing the tile has disturbed the waterproof membrane, you must repair the membrane before re-tiling. This is not optional.

Laying the New Tile

1. Butter the back of the new tile and apply adhesive to the substrate using a notched trowel. Aim for full coverage — at a high level of contact — check the adhesive manufacturer's data sheet and any applicable NZ Standards for the specific coverage requirements in your situation.
2. Press the tile firmly into position, twisting slightly to bed it in.
3. Use tile spacers to maintain consistent grout joints with surrounding tiles.
4. Check it's level with adjacent tiles using a straightedge. Adjust as needed before the adhesive sets.
5. Allow to cure fully before grouting — typically 24 hours, but check your adhesive's instructions.

Grouting and Finishing

Once the adhesive has cured, remove the spacers and apply grout with a rubber float, pressing it firmly into the joints. Wipe off excess with a damp sponge before it hardens. Buff the tile clean with a dry cloth once the grout has started to set.

Matching existing grout colour can be tricky, especially in older homes. Take a photo of your grout to a Mitre 10 or Bunnings store, or ask a tiling specialist — they can often help you find the closest match.

In wet areas, finish the repair with a bead of silicone sealant (not grout) in any movement joints, such as where the floor meets the wall.

When to Call a Professional

Call a qualified tiler if:

• Multiple tiles are cracking or hollow — this suggests a systemic problem with the substrate or original installation
• The substrate is damaged or the waterproof membrane is compromised in a wet area
• You can't find a matching replacement tile and need help sourcing one
• The cracked tile is large-format (600mm+), over underfloor heating, or in a pool or outdoor area
• You're simply not confident with the tools involved

A skilled tiler will also be able to advise whether the crack was caused by movement — in which case a simple patch may crack again without addressing the root cause. You can find experienced local tilers on tradedirectory.co.nz.

Sources & Further Reading

• BRANZ — Tiling guidance and substrate information
• MBIE Building Performance — NZ Building Code
• Ardex NZ — Tile adhesives and waterproofing products
• Mapei NZ — Tile installation systems
• Sika NZ — Waterproofing and adhesive solutions
• Bunnings NZ — Tiling tools and materials