Bathroom floor tiles: how to choose ones that last

What a bathroom floor has to cope with

A bathroom floor gets splashed every day, walked on barefoot, cleaned with strong products and occasionally hit by a falling glass bottle. Upstairs it usually sits on timber joists that move slightly as people walk across the room, and in many houses it also carries the weight of a bath full of water. Any tile choice has to survive all of that at once.

That is why we look at the floor itself before talking about colours. A beautiful tile on a springy floor will crack along its grout lines, while a modest tile on a stiff, well prepared base can look sharp for decades.

Slip resistance and finish

Polished and high gloss tiles are lovely on a wall and risky underfoot once wet. For a bathroom floor, choose a matt, honed or lightly textured surface, and ask the supplier for its slip rating. Manufacturers test tiles wet and dry, and the wet figure is the one that matters here, especially for children and older relatives.

Small tiles help as well. More grout lines mean more edges for a foot to grip, which is why mosaics are often used in a level shower area even when the rest of the floor is laid in a larger format.

Porcelain, ceramic or natural stone

Porcelain is fired harder and absorbs very little water, so it is the default recommendation for bathroom floors. The colour usually runs through the body of the tile, which means a chip is far less obvious. Ceramic is softer and lighter, cuts more easily and suits walls well, but many ceramic ranges are only rated for wall use, so check before ordering them for a floor.

Natural stone such as slate, limestone or travertine gives a warmth nothing else quite matches. It also needs sealing, gentle cleaning products and a little more patience, and some softer stones will mark if hair dye or a strong cleaner is left on them.

Tile size, layout and grout lines

Large tiles make a floor feel calmer because there are fewer joints to catch the eye. They also demand a flatter base, and they cannot bend around the gentle slopes needed near a level shower. Our guide on large format tiles and lipping explains why big tiles show every small dip in a floor.

Layout is planned before the first tile goes down. We set out from the most visible line in the room, usually the doorway or the bath front, so cut pieces end up under the vanity unit or behind the toilet rather than right where you step in.

Read more: Large format tiles and lipping

Underfloor heating under tiles

Tile is one of the best finishes over underfloor heating because it passes heat through quickly and is unaffected by warmth. An electric mat is normally bedded into the adhesive or a thin levelling layer, with insulation boards underneath so the heat rises into the room rather than into the joists. The thermostat probe and cable route are planned before tiling starts.

Read more: Underfloor heating in kitchens and bathrooms

Falls and level-access shower areas

If the shower has no tray, the floor has to slope gently towards the drain. Smaller tiles follow those slopes neatly, while larger tiles need the falls planned in straight planes, often with a linear drain along one wall. Either way, the waterproofing goes down first and the tile is the visible finish over it, not the thing keeping the water out.

The base: boards, levelling and decoupling

Before tiling a timber floor, we check for movement and screw it down, then overboard with a tile backer board or plywood suited to wet rooms. On concrete, a thin levelling compound corrects dips. Where a floor still moves slightly, a decoupling membrane between base and tile lets the two shift independently so the tiles do not crack. Our guide to uneven subfloors covers this preparation in more detail.

Read more: Fixing an uneven subfloor before new flooring