A guide to tile grout

In rooms that get the toughest treatment, such as kitchens and bathrooms, a ceramic-tiled floor is often the first choice. It is virtually indestructible, and although a chipped or cracked tile is almost inevitable in an active household, it is easily fixed. The stains suffered by the tiles and grout due to wear and tear, are also easily treated. Here is a guide to tiles and their sealing grout.

Applying the grout

When laying tiles, it will be vital to apply a suitable sealer. Grout sealer keeps water and dirt from penetrating and staining, saving you a lot of work and possibly preventing damage to the underlying structure. If your tiles are glazed, take care not to get the grout on the tile surface. Use an artist's paintbrush to apply the sealer just around the joints. If, on the other hand, the tiles aren't glazed, use a combination grout-tile sealer to seal the tiles at the same time that you seal the grout.

Tile over a sound base

Never lay ceramic tiles and grout directly over old floorboards. The natural flexing of the boards as you walk across the floor will cause the grout joints between the tiles to crack, and this will ruin the waterproof quality and durability of the floor. Lay a plywood base Cover the boards first with a layer of 15mm exterior-grade plywood, screwing the sheets securely to the boards underneath, and seal the ply with a coat of wood primer before applying the tile adhesives. Remember that the floor level will be raised by up to 40mm by the thickness of the plywood, adhesive and the tiles themselves, and consider how this might effect the junction between the tiled floor and the flooring in adjacent rooms.

Replacing broken tiles

To replace a broken tile, first you will need to remove the grout around the damaged tile with a grout saw. Hit the tile with a hammer and cold chisel to break it, then chisel out the tile along the crack lines, working from the middle of the tile towards the edge. After that, chisel the old grout out of the opening. Apply the tile adhesive to the back of the tile using a notched trowel. Press the tile firmly in place and check that it is flushed with the surrounding tiles. Let the adhesive dry overnight before grouting around the new tile.

Cleaning grout

Cleaning grout is vital when dirt starts to build up on it. Try one of the propriety grout cleaners, available from DIY stores and tile suppliers, or mix 200ml of bleach with two litres of water. Always make sure that the room is well-ventilated and put on a pair of rubber gloves.