1Having a good seal around your bath/shower is very important as it prevents water from seeping down through the floor. The vast majority of damp spots in ceilings are caused by broken seals in the bathroom.
2Use a paint scraper or sealant remover to remove any old sealant from around the bath. Then use a scouring pad dipped in methylated spirits to remove any last bits of sealant from the bath. (Chemical silicone removers are also available which help soften/break-down the seal and makes it easy to remove the silicone.)
Top Tip: Fill the bath half way with water before applying sealant. This way you will allow for any movement from the weight of the bath when it is actually being used.
3Cut the nozzle to size, to allow the silicone out. For best results cut the nozzle at an angle of 30 degrees with a sharp utility knife.
4Run the nozzle along the gap releasing the silicone as you go. Try to be steady with your application to achieve the best finish.
5Coat your finger in washing-up liquid and run along the silicone seal. This will remove any lumps from the seal and give an even finish.