Junctions between tiles and other surfaces are normally sealed with silicone sealant, which can deteriorate over time. Once a seal begins to allow water penetration, it must be replaced Tools and materials Window scraper or sealant remover, masking tape, sealant

Scrape away the old sealant. A window scraper is ideal, or use a proprietary sealant remover. Stick masking tape 2mm (1⁄12in) from each side of the joint. This will ensure that the sealant will have straight edges. Apply silicone sealant along the gap, and smooth with a wetted finger. Remove tape and smooth again if necessary.

Extracted from DIY- Know How With Show How published by Dorling Kindersley, price £25.00. Copyright © 2006 Dorling Kindersley Ltd, Text copyright © 2006 Julian Cassell and Peter Parham