Materials you'll need:

• Tile cleaner
• Grouting
• Soft rags
• Tile grout and sealer spray.

Tools you'll need:

• Sharp tool such as old kitchen knife
• Sponge or brush

If the grouting (the white cement) between tiles has eroded or deteriorated, it not only looks unsightly, it can harbour mildew and dirt and allow water to get in behind the tiles. You should replace the grouting when it reaches this stage and it is not very difficult, but rewarding in terms of results.

First clean and remove all the old, loose grouting, digging it out from between the tiles with a sharp tool such as an old kitchen knife.

Wash out all the fragments of grout and clean the tiles to remove old soap and grease. Rinse with clean water and allow drying.

Mix the grouting cement as directed on the product, usually to about the texture of cake batter. It should be smooth and well mixed.

Spread this over the joints between the tiles using a brush, sponge or damp cloth. Make sure it goes well into the joints. It will not harm the tiles if some of the grouting overlaps onto tile faces.

Gently smooth along the joints to remove excess grouting. Apply more grouting to any spaces showing and smooth again.

Leave the grouting to set about 15 minutes then wipe over the tile surfaces with a soft, dry towel to remove the excess.

Leave the grouting to cure for the time specified on the product (usually overnight or a little longer). Then polish the tiles with a soft cloth to remove any remaining grouting and polish the surface. When the grouting is well cured, it can be protected with a spray-on tile and grout sealer.