What slip rating do I need for a bathroom floor?

Bathroom floors are wet and walked on barefoot, so a floor tile with an appropriate slip resistance rating for internal wet areas is what you want. Tile suppliers publish the ratings. It matters most in households with older occupants or young children, and it cannot be improved once the tile is down.

Can I use wall tiles on a bathroom floor?

Usually not a good idea. Wall tiles are not required to have any slip resistance and are often not rated for floor traffic. Many ranges offer a matching floor version, which is the better route if you want the same look throughout.

Bathroom Floor Tiles: What Actually Works Underfoot

Q: Are large tiles suitable for a shower floor?

Less so. A shower floor has to fall towards the waste in more than one direction, and a large rigid tile cannot follow a compound slope. Smaller formats or mosaics conform to the falls, which is why they are common on shower bases.

The floor is the tile decision with the most consequences and usually the least attention. It gets wet, it gets walked on barefoot, and it has to slope towards a waste while looking flat.

Slip resistance first

Tiles carry slip resistance ratings, published by the supplier. A bathroom floor should have one appropriate for an internal wet area.

This gets skipped because it is the least interesting part of choosing a tile. It is also the only performance characteristic in the room where the failure mode is somebody falling over, and it cannot be changed after installation.

It matters most where there are older occupants or young children. It is worth asking about specifically, because a beautiful polished tile that is treacherous wet is a genuine problem you will live with.

A practical note: higher slip resistance usually means more surface texture, and more texture means slightly more effort to keep clean. That is a real trade-off, and for most households it is worth accepting.

Material

Porcelain is the sensible default. Dense, very low water absorption, no sealing required, hard wearing, and available with appropriate slip ratings in almost any appearance.

Ceramic is softer and more porous. Fine on walls, generally not the best choice for a bathroom floor.

Natural stone is beautiful and demanding. It is porous so it needs sealing and resealing, and acidic bathroom cleaners can etch it. Choose it deliberately. The comparison is here.

Format and falls

This is where the shower floor differs from the rest of the room.

The main floor can take a large format. Fewer grout lines, calmer surface, less grout to clean. It needs a flat substrate, because a large rigid tile bridges any dip and shows it as lippage. Large format tiles have real requirements.

The shower floor has to fall towards the waste, and with a centre waste it falls in several directions at once. A large rigid tile cannot follow a compound slope. Smaller formats and mosaics conform to it, which is why shower bases are so often mosaic even where the rest of the floor is large format.

A linear drain against one wall changes this. The floor then falls in a single plane, which means a larger tile can be used in the shower and the floor can run continuously through. It is one of the better decisions available in a small bathroom.

Continuing the floor into the shower

Changing tile at the shower threshold cuts a small floor into two smaller areas and makes the room read tighter. Running the same floor through, where the falls allow it, is one of the highest-impact choices in a small bathroom.

Grout on a floor

Floors show grout wear more than walls, because that is where the traffic and the dirt are.

Brilliant white grout on a bathroom floor will not stay brilliant white. A mid tone hides normal life far better and still reads as clean. Sealing the grout helps considerably on a floor.

What the substrate has to do

Tiles do not fix a floor, they reveal it. If the substrate is not flat, a large tile will show it. If the falls are wrong, the shower will pond for the life of the bathroom regardless of the tile.

The screed that establishes those falls goes in before waterproofing, which is why the floor is decided early in the order of works.

Ordering

Allow about 10 percent extra for cuts, more in a small room. Order the whole job in one batch, because shade varies between production runs. Keep the offcuts.

Our guide to choosing tiles covers the full picture, and our tiling services cover supply and laying across Sydney.