How to tile a shower

Video by Tommy's Trade Secrets. This walk-through draws on the techniques shown in "Tommy's Trade Secrets — How To Tile A Wall", which covers setting out, applying adhesive, spacing, and cutting tiles cleanly. The principles apply directly to shower enclosures — the section on starting from a true vertical line and working outward is particularly worth understanding before you open the bucket of adhesive.

1. Prepare and waterproof the walls before tiling

This is the step most people skip, and it is the one that causes the most problems later. Plasterboard, even moisture-resistant board, should be treated with a tanking membrane or a brush-applied waterproof coating before any tiles go on. In a shower enclosure the walls are going to get wet every day — that moisture needs something to stop it getting behind the tiles and into the wall structure.

Apply the tanking slurry or membrane in two coats, paying particular attention to the corner joints and the join between the wall and the shower tray or tiled floor. Embed waterproof tape into the wet membrane at internal corners — those corners are where leaks nearly always start. Let it cure fully before tiling. It is worth waiting an extra day rather than rushing. To be fair, the tanking takes about an hour to apply; the curing is the only thing you are waiting for.

2. Set out the tile layout before you mix any adhesive

Hold a full tile against the wall and work out where the cuts are going to fall. Ideally you want similar-sized cut tiles on both sides of the enclosure, with full tiles centred on the most visible wall face. Avoid tiny slivers of tile at corners — anything less than about a third of a tile width looks awkward and is harder to cut cleanly.

Use a long spirit level to mark a true horizontal datum line on the wall. A lot of shower trays and floors are not perfectly level, so starting from a spirit level line rather than from the tray edge is the right approach. It also means your grout lines run horizontally, which is what the eye naturally follows. Mark your vertical centre line on the main wall face, too — that gives you a cross to start from.

3. Apply the tile adhesive and bed the first tiles

Use a flexible, waterproof adhesive rated for wet areas — standard wall tile adhesive is not good enough for a shower. Apply it to the wall with a notched trowel, working in sections of about half a square metre at a time so it does not skin over before you get the tiles on. Comb the adhesive in one direction to help you spot any areas where the coverage is thin.

Press the first tile firmly onto the adhesive with a slight twisting motion to bed it in. Fit tile spacers immediately — 2 mm is typical for a modern shower, though some larger format tiles look better with a 3 mm joint. Work outward from your datum lines, keeping the tiles plumb and level as you go. Check with the spirit level every few tiles rather than every single one — small adjustments build up quickly if you leave them.

4. Cut the border and corner tiles accurately

Measure each cut tile individually rather than assuming the gap is consistent all the way around. In older houses particularly, walls are rarely perfectly parallel. A good electric tile cutter makes a cleaner job than a manual scorer for most tiles; for awkward shapes around pipework or corners, a tile nipper or an angle grinder with a diamond disc does the job.

Always dry-fit a cut tile before spreading adhesive on the wall. It sounds obvious, but it is easy to cut ten tiles the same size and find the tenth one does not fit because the wall has drifted slightly. Internal corners in a shower are particularly prone to this. That said, a well-set-out job in a reasonably square room should not need much adjustment as you go.

5. Grout the tiles once the adhesive has fully set

Leave the adhesive to cure for at least 24 hours — 48 hours is better — before grouting. Use a flexible, waterproof grout for the shower interior. Mix it to a smooth, firm paste, press it into the joints with a grout float held at a diagonal to the tiles, and remove the excess with a damp sponge before it starts to harden on the tile face.

Work in sections and keep the sponge wrung out well — too much water in the grout causes it to shrink and crack later. Buff the tile faces with a dry cloth once the grout has hazed over but before it sets hard. Dried grout left on glazed tiles for a day or two can be surprisingly stubborn to shift, particularly on textured tile surfaces.

6. Silicone all internal corners and the junction with the tray

Grout in corners cracks. It always does, eventually, because the two walls move independently and grout is not flexible enough to cope. The joint between the wall tiles and the shower tray is the most critical one of all — if water gets through there it goes straight into the floor structure. Use a good quality sanitary silicone in a colour that matches the grout, and run a neat, continuous bead with no gaps.

Mask either side of the joint with tape, apply the silicone, smooth it with a wet finger or a silicone tool in one steady pass, then pull the tape off before the silicone skins. Leave it to cure for the time stated on the tube before running the shower — usually 24 hours, sometimes longer in a cold bathroom. It is the last thing you do, but arguably the most important step in keeping the whole job watertight long-term.

When to call a handyman

Call Richard if the existing shower walls are damp-damaged or the plasterboard needs replacing before tiling can start, if the tiles are large format and need specialist adhesive and support battens to stay on the wall while setting, or if you want the whole job done properly in one go — waterproofing, tiling, grouting, and siliconing. Getting the waterproofing step wrong on a shower is an expensive mistake, and it is one that does not always show itself immediately.