Technically you can lay standard ceramic floor tiles in a garage, but in most cases it's not a good idea. Garages are tough environments — vehicle loads, oil spills, temperature swings, and moisture all take a toll — and standard ceramic tiles simply aren't engineered to cope. Choosing the wrong tile or skipping proper preparation can lead to cracked, slippery, or lifting tiles within a year or two.
Why Standard Ceramic Tiles Struggle in Garages
Standard ceramic floor tiles are designed for interior living spaces: kitchens, bathrooms, and hallways. In a garage they face conditions they weren't made for:
- Point loads and impact – A car jack, a dropped tool, or even a vehicle tyre can crack a ceramic tile. Ceramic is brittle compared to porcelain or purpose-made industrial tiles.
- Freeze-thaw cycles – In cooler NZ regions (Canterbury, Otago, Central Plateau), garages can drop below zero. Standard ceramic tiles often have higher water absorption rates, making them vulnerable to frost damage as absorbed moisture expands.
- Oil and chemical exposure – Unglazed or lightly glazed ceramics can absorb oil, brake fluid, and other chemicals, staining permanently and weakening the tile over time.
- Slip risk – Many standard ceramic tiles become dangerously slippery when wet or oily. NZ building practice (and the NZ Building Code) requires adequate slip resistance in areas likely to get wet.
What Tiles Are Actually Suitable for a Garage Floor?
For a garage floor, look for tiles that meet these criteria:
| Property | What to Look For |
|---|---|
| Tile type | Porcelain (fully vitrified) or purpose-made industrial ceramic |
| Water absorption | Less than 0.5% (Group BIa or BIb per ISO 10545) |
| Slip resistance | R10 or R11 rating for wet/oily conditions |
| Thickness | 10 mm or greater for vehicle traffic |
| PEI wear rating | PEI IV or V |
Fully vitrified porcelain tiles are the most popular choice for NZ garages. They're dense, low-absorption, frost-resistant, and available in finishes that offer good slip resistance. Ask your tile supplier specifically for tiles rated for garage or commercial use.
Preparing the Concrete Slab — This Step Is Critical
Even the best tiles will fail if the slab underneath isn't properly prepared. Garage slabs in NZ are often contaminated with oil, have surface laitance (a weak top layer), or aren't level enough for tiling.
Key preparation steps:
- Degrease thoroughly – Use a concrete degreaser to remove all oil and grease. Adhesive will not bond to a contaminated surface.
- Grind or scarify the surface – Mechanical grinding removes laitance and opens the concrete pores for better adhesion. Hire a concrete grinder from Bunnings or Mitre 10, or engage a tiler who has the right equipment.
- Check for moisture – Concrete slabs can transmit ground moisture upward. Carry out a plastic sheet test (tape a 500 mm square of plastic to the slab for 24–48 hours and check for condensation underneath). If moisture is present, a moisture barrier or epoxy primer is essential before tiling. Products from Ardex or Mapei are widely used by NZ tilers for this purpose.
- Level the slab – Use a floor levelling compound to fill low spots. A flat slab is essential for full tile bedding and prevents hollow spots that crack under load.
- Allow curing time – New concrete slabs should cure for at least 28 days before tiling.
Choosing the Right Adhesive and Grout
Don't use standard wall-tile adhesive. For a garage floor you need:
- A flexible, polymer-modified tile adhesive rated for floor use and heavy-duty conditions (check the manufacturer's technical data sheet).
- Epoxy grout or a flexible cement-based grout that resists oil and chemicals. Standard grout is porous and will absorb oil and stain badly.
Brands like Ardex, Mapei, and Sika all offer suitable systems — always follow the manufacturer's specifications for the product combination you choose.
Movement Joints — Don't Skip These
Concrete slabs move. Without movement (expansion) joints in the tile layout, the tiles will crack as the slab expands and contracts. As a general guide, movement joints should be installed:
- At all existing control joints in the slab (never tile over these)
- Around the perimeter of the tiled area
- At intervals across large floor areas (your tiler can advise on spacing)
This is a common area where DIY garage tile jobs go wrong.
Do You Need a Building Consent?
In most cases, tiling an existing garage floor is exempt from building consent under Schedule 1 of the Building Act 2004 as it's general repair and maintenance. However, if you're altering drainage, adding a floor drain, or making structural changes, consent may be required. Always confirm with your local council before starting work — rules can vary.
When to Call a Professional
Garage floor tiling is a physically demanding job that requires proper equipment and experience to get right. Consider hiring a qualified tiler if:
- The slab has significant moisture issues or cracks
- You're tiling a large area or one that will carry vehicle loads
- You're unsure about slab preparation or movement joint placement
- You want the job to last and look professional
Tiling is not licensed restricted work in NZ, but a skilled tradesperson will have the tools, product knowledge, and experience to avoid costly mistakes. You can find qualified local tilers on tradedirectory.co.nz.
For any floor drainage work connected to the garage, note that drainlaying is restricted work under the Plumbers, Gasfitters and Drainlayers Act and must be carried out by a licensed tradesperson registered with the PGDB.
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