#DIY guide: Wall-tiles

When buying tiles, purchase more than you need; a few are likely to break in transit and it's good to have leftovers in case they discontinue the colour. If one or two tiles do break, all is not lost, says professional tiler James Fogarty: Don't immediately discard broken tiles - sometimes they can be used as cuts.

Tools and materials

Screws, tape measure, spirit level, drill, serrated adhesive trowel, tile spacers, tile saw, plumb line, dry or wet tile cutter, rubber grouting float, soft dry cloths, goggles and gloves, battens, hammer and bolster chisel, sandpaper, tiles and tile adhesive, screwdriver

1. It's not advisable to tile on top of existing tiles, but in some houses you may not have a choice. James explains: In older houses the original tiles tend to be laid on cement, so if you tried to break them off the walls, the house would cave in. In this case you can tile on tiles, but of course you lose wall space.

Otherwise your walls need to be bare, with no remnants of tiles, wallpaper or paste residue. Remove old tiles using a hammer and bolster chisel (and wearing safety goggles); make a crack in the tile and it should pop off. If you find you need to cut back to the brickwork (some older tiles can be really awkward), then replaster the walls before tiling - this may require professional help.

2. Use sandpaper to dust the walls down and then apply a sealer; this should ensure the tile adhesive you're about to put on stays moist for longer. Choosing an adhesive can be a bit of a minefield; avoid any problems by taking a sample of the tile to your local supplier (use darker adhesives for terracotta-style tiles, lighter ones for white tiles). And remember that for cork tiles you will need a different type of adhesive, which acts like a glue and dries instead of sticking.

3. The best way to ensure your tiles are lined up correctly is to use horizontal and vertical wooden battens as your tiling axes , not the floor or ceiling which are often very uneven. Take a horizontal batten, advises James, and, with your spirit level, get a straight line which is one normal tile size (12x12) off the floor. Pencil-mark that height across the room, then pin the battens on and start tiling above this mark.

4. To position the vertical batten, drop a plumb line from the top of the wall, draw along it and then fix your vertical batten to that line. Now you have a framed outline to start tiling upwards from.

5. Spread the adhesive on to this area of wall, using a toothed spreader (pressing hard so you can see the ridge marks) to ensure an even spread of adhesive horizontally across the wall. The back of the adhesive should recommend what size spreader to use. Now press each tile against the wall, placing a tile spacer at each corner to space them evenly.

6. James advises: Lay a strip of wood diagonally flat against each newly laid tile and push it into the adhesive to make sure the tiles are laid flat against the wall. Use a wall scraper to go round the edges of each tile, getting rid of excess adhesive. And when you have finished tiling upward, leave the adhesive to dry for about six hours, take the battens off and start working around the edges (this may involve cutting tiles).

7. As you are going along it's worth picking up a spirit level to check the tiles are straight. Get a brush for areas where a trowel is too big to fit. Use damp cloths to wipe away any excess adhesive.

Cutting tiles

You can either use a drill or a proper tile cutter. James says: A wet cutter has a diamond wheel and a blade that goes in water. It gives a perfect cut, especially with porcelain (where you can't use a drill because it breaks the tile). Dry tile cutters are also good for cutting straight edges, but for more intricate shapes and tricky angles, use a powered wet cutter.

Tiling around sockets

Turn off your electricity supply, then half-unscrew the sockets off the wall so they are hanging. You want to fit the tiles so that they tuck in behind the sockets rather than leaving a gap around them. Measure around the socket, then add 2cm inside each edge.

Grout is the stuff you apply between tiles to seal them in place. Grout tiles once the adhesive has dried fully (24 to 36 hours later). The best grout is waterproof and mould-resistant; some come ready-mixed. Use a grout float - a rubber-faced tool with foam backing - for large areas. Spread the grout across the tiles at right angles to the joins. Use a damp sponge to remove excess. Once the grout is dry, polish the surface with a dry cotton rag.

For those who think only of old terracotta-coloured ceramic flooring, times have changed and there are now a plethora of jazzy tiles on offer to transform your floor, from rubber to cork (in assorted colours) to metallic tiles and natural stone such as marble, slate and limestone.

To lay them, you'll need tile adhesive appropriate to the surface, tile spacers, toothed spreader, tile cutter, sponges and cloth, white or coloured grout, a coin.

Tiles can be laid on concrete and suspended timber floors. With a concrete floor, it's important to clean it first with warm water and washing-up liquid. With wooden floors, James Fogarty advises: Unlike with concrete, wooden floors move and joints open up in the grouting - so you need to use a rubber base adhesive that moves with the floor. And if it's a really bad floor, put plywood down and screw it in, then apply adhesive.

To lay the tiles, do a dry run first. Follow the technique for wall tiles to create a corner of battens on the floor, then get a toothed spreader and start laying the adhesive covering a square metre. Apply the first tile and then lay the rest, placing spacers in between.

If you are working with pattern, make sure it matches up as you lay so that you don't have to remove it and lay the tile again!

After laying the tiles, leave to dry thoroughly and then start grouting. Leave the floor for 24 to 48 hours before walking on it.

When tiling a bathroom floor use a waterproof grout. It's advisable to take the toilet pan off the floor and tile underneath, rather than trying to work around it (hard tiles aren't as flexible as carpet). For fixtures that you can't remove, such as pipes, mark the centre of the pipe on the top and side edges of the tile and draw lines across from these points. Draw around a coin where the two lines cross. Cut straight through the centre of the circle and use a tile saw to cut out the rest of it.

Small mosaic tiles are very popular at the moment; they come on a sheet of backing and are easy to lay (firedearth.com). British Ceramic Tile's new range WET was created by designer Wayne Hemingway (britishceramictile.com ). Or for retro colours and styles, try Craven Dunnill's Esencia range (cravendunnhill.co.uk ).

For video tips to tiling, check out toppstiles.co.uk