Silicone - Clear

Clear silicone sealant, the version bought when the joint should disappear rather than be finished in a colour. Being transparent, it works against any background - glass and glazing beads, mirror edges, tiles of any shade, shower screens, basins, sinks and worktop edges, aluminium and uPVC window trims - which is why most shops sell more clear than every colour put together. It stays flexible after curing, so it absorbs the small movement between materials that expand at different rates, which is precisely where rigid filler cracks and lets water through. Cut the nozzle no wider than the joint, run it in one pass, and tool it off with a wet finger or a spatula before it skins. Clean the joint out first: silicone will not stick to old silicone, dust or grease.