Do I tile the wall or the floor first?

This looks like a preference question and it is not. Whichever surface goes second has to be cut to fit the first, and whichever junction is formed last is the one that can be sealed properly. Getting the sequence wrong usually shows up as an ugly, unsealable gap at the very bottom of the wall — the exact place water collects.

Step by step

1. Establish what is being fitted in the room and when.A bath, a shower tray, a shower enclosure and kitchen units all change the answer. Anything that will sit on the floor and be tiled up to needs to be in position first.
2. If there is a bath or tray: fit it, then walls, then floor.The bath or tray must be fully installed, levelled and supported before the wall tiling starts, because the wall tiling has to finish onto it with a proper sealant joint. Tiling the walls first leaves you sliding a bath in under finished tiles with no way to seal the top edge.
3. If the room is empty: floor first, then walls.Tile the floor, let it set, then tile the walls down onto it, finishing with a sealant joint rather than grout at the wall-to-floor junction. The wall tiles then hide the floor's perimeter cut and the movement gap.
4. Either way, protect the surface you have just laid.Hardboard or thick card over a new tiled floor while you tile the walls. Dropped adhesive sets hard, dropped tools chip, and kneeling on a fresh floor moves tiles.
5. Never grout the junction between wall and floor.It is a change of plane and therefore a movement joint. It gets flexible sealant, whatever the order of work.
6. Plan for the skirting or the tile trim at that junction.Decide before you start whether the wall tile runs to the floor, whether there is a tiled skirting, or whether timber skirting sits on the tiled floor. It changes where the wall tiling stops.

Tips

• In a kitchen, fit the units and worktop before tiling the splashback: the tiling then finishes onto the worktop with a sealant joint, which is what you want.
• If the floor tile is going under a bath, it does not need tiling under the whole bath — but it does need to run far enough that no gap shows at the panel, and the floor must be level where the feet land.
• If the walls are already tiled and you are only replacing the floor, you may need a thinner floor build-up or an extra trim to close the gap left at the bottom of the wall tiles.

Common mistakes

• Tiling the walls before the shower tray is fitted — The tray then has to slide in under finished tiling. There is no way to seal the top of the upstand properly, and the joint at that point is the single most common place a shower leaks into the floor below.
• Tiling the floor last in a room with no bath or tray — It works, but the floor tiles then have to be cut to fit against finished wall tiles all the way round, which is far more cutting and far less forgiving than running the floor in first and covering its edges with the wall tiling.
• Grouting the wall-to-floor junction — Two planes that move independently. Rigid grout in that joint cracks along its full length, and the crack lets water into the floor build-up.

Questions people ask