How to Tile a Bathroom Yourself: Tools, Materials and Mistakes to Avoid

Tiling a bathroom yourself is one of those projects that strikes fear into the hearts of capable DIYers who've successfully plastered walls, laid floors, and installed kitchens. The fear is understandable — tiles are permanent, expensive, and highly visible. Get it wrong and the evidence is difficult to hide. But approached methodically, bathroom tiling is well within the capabilities of any homeowner willing to take the time to prepare properly and not rush.

This guide covers everything you need — tools, materials, technique, and the mistakes that consistently derail bathroom tiling projects.

Planning and Layout

Before you touch a tile, spend time on your layout. This is where most bathroom tiling projects succeed or fail, and it costs nothing except an hour of careful thought.

Find the centre of the wall and work outward symmetrically. You want any cut tiles at the ends or corners to be equal in size and at least half a tile wide — a thin sliver of tile in a corner looks amateurish and is difficult to cut cleanly. Use a long spirit level and a pencil to mark horizontal and vertical datum lines on the wall.

For a shower enclosure or wet wall, start the lowest full horizontal course at least one grout joint above the bath or shower tray edge. This protects the vulnerable joint between the tray and the wall from constant water movement. The junction between bath/tray and tiles is the single most common source of water ingress — use a dedicated sanitary silicone sealant here, never grout.

Tile Quantity

Measure your wall area, divide by the tile area, and add 15% for wastage and cuts (more if you're using a diagonal layout, which increases waste to 20–25%). Order all tiles from the same batch number — colours vary slightly between batches and the difference, though subtle, is visible in a finished wall.

Tools You'll Need

• Electric tile cutter (wet saw) — hire from HSS or Speedy Hire for around £30–40 per day. For straight cuts only, a score-and-snap cutter (from £15 at Screwfix) is adequate, but a wet saw is far more versatile and gives cleaner results.
• Angle grinder with diamond blade (for curves and notches around pipes)
• Notched trowel — the notch size should match the adhesive manufacturer's recommendation for your tile size. For tiles up to 300×300mm, a 6mm notch; for larger tiles, 10–12mm.
• Grout float — a rubber float for pushing grout into joints
• Tile spacers — 2mm for most bathroom walls; 3mm for larger format tiles
• Long spirit level
• Bucket, mixing paddle, sponges
• Silicone gun for the bath/tray junction

Surface Preparation

Bathroom tiles can be laid over existing tiles (if they're firmly adhered and the wall can take the extra weight), over plasterboard, or over solid plaster. Whatever the substrate, the surface must be:

• Flat — use a straightedge to check. Any high spots need grinding down; any hollows deeper than 3mm need filling.
• Sound and dry — any loose, blown, or damp plaster needs to be cut out and repaired before you start.
• Clean and free of grease — wash walls with sugar soap and allow to dry completely.
• Sealed — new plasterboard, bare plaster, and absorbent surfaces should receive a coat of diluted PVA or a dedicated tile primer (such as BAL Primer from Screwfix). This controls suction and improves adhesive bond.

In wet areas — shower enclosures, around baths — fit tile backer boards (such as Wedi, Hardiebacker, or Aquabacker) rather than relying on standard plasterboard. Standard plasterboard, even moisture-resistant "pink" board, will deteriorate behind tiles in consistently wet conditions. Tile backer boards are waterproof and dimensionally stable — they're a cheap insurance policy against major future problems.

Choosing the Right Adhesive

Use a waterproof adhesive rated for wet areas — not standard tile adhesive, which is only water-resistant. For most bathroom wall tiling, a powder adhesive mixed with water (such as BAL White Star or Mapei Keraflex) gives good results. Ready-mixed adhesives are more convenient but tend to have lower bond strength and are not always suitable for large-format tiles.

For tiles larger than 600×300mm, use a large-format tile adhesive and apply adhesive to both the wall and the back of the tile (this is called "back-buttering" and dramatically reduces the risk of voids behind large tiles, which are a common cause of cracking). Large tiles need support while the adhesive cures — use tile wedges or a batten fixed temporarily to the wall at the correct height.

The Tiling Process

1. Mix adhesive to a peanut butter consistency — not too wet, not too stiff. Spread on the wall with the flat face of the notched trowel, then comb through with the notched edge, held at 45°, to create uniform ridges. Work in areas of about 0.5m² at a time — don't spread more adhesive than you can tile in 15–20 minutes before it skins over.
2. Press the first tile firmly onto the adhesive, sliding slightly to key into the ridges, then pressing into final position. A slight twisting motion helps collapse the adhesive ridges and maximise contact. Check for level after every few tiles.
3. Insert spacers between tiles to maintain consistent grout joints. Remove them before the adhesive is fully set (after about 2 hours for most wall adhesives).
4. Cut tiles as needed. Always wear safety glasses when cutting tiles — sharp fragments travel at speed. For straight cuts, score firmly with a carbide wheel cutter and snap cleanly. For angles and shapes, use the wet saw or angle grinder.
5. Allow adhesive to cure fully before grouting — typically 24 hours, more in cold or damp conditions. Don't grout too soon.

Grouting

Use a waterproof grout for all bathroom applications. For joints under 3mm, use unsanded grout. For wider joints (3mm and above), sanded grout is more appropriate. Mix to a smooth paste and apply with the grout float, working diagonally across the joints to force grout in fully.

Wipe away excess grout with a damp sponge before it sets — change the water frequently. A haze will remain on the tile face; buff this off with a dry cloth once the grout has hardened (typically 30–60 minutes after application).

Do not grout the internal corners or the junction between wall tiles and bath/shower tray. These movement joints must be filled with sanitary silicone sealant, which allows the inevitable slight movement between surfaces without cracking. Use a colour-matched sealant — major grout brands (Mapei, Rubi, BAL) all offer matching silicone.

Common Mistakes

• Not preparing the surface properly — adhesive applied to unprepared plaster or contaminated surfaces will fail. The tiles will fall off. It happens more often than you'd think.
• Using grout in movement joints — the corner between walls, and the tile-to-bath junction, will always crack if grouted. Use silicone.
• Rushing the adhesive cure — grouting before adhesive is fully set causes tiles to shift during grouting. 24 hours minimum.
• Not checking for level frequently enough — tiles that start off level but gradually drift out of true are very obvious in a finished bathroom. Check every few tiles.
• Buying from different batches — tiles from different production batches can vary in shade. Always buy 15% extra from the same batch and keep spares.

Done properly, a tiled bathroom will look professional, function perfectly, and last for twenty years or more. The upfront investment in good tools, quality materials, and proper preparation is repaid many times over in a result you'll genuinely be proud of.