Shower Silicone - The Right Way
How To Seal Tile To Tubs, Showers, And Other Surfaces
A very common sight in any bathroom is peeling, dirty caulk or sealant. The most commonly used sealant in bathroom renovations today is silicone. You should find silicone instead of grout anywhere a tile installation changes plane and where tile meets fixed building elements such as tubs, shower bases or countertops. While it is a durable product, application must be done correctly to ensure performance. We will only be discussing tile applications here
When tiling an inside corner in a shower, care must be taken to maintain a small gap in the corner to allow for expansion of the installation when it absorbs water. Any tile, regardless of its quality will absorb some water. This gap cannot be filled with grout and must be sealed with silicone. Problems arise when no gap is left between the adjoining tiles during installation, and the silicone is applied on the surface of the tile to seal this area. When silicone is applied on the surface of a tile, it's always feathered to a very thin film at the edge. Once dry, when you go to wipe down the silicone this film will lift, opening up the entire bead to eventual failure. The silicone must be forced into the joint between the tiles, and tooled flush. The silicone is then the full depth of the tile, making it stronger and less prone to discolouring.
The same principles apply where tiles meet a tub or shower base. This often hard to clean and maintain area is often subject to the same mistakes, making it even more difficult. Flush installed, high quality, colour matched silicone makes your shower that much more beautiful and easier to clean. Stay away from grout-caulks or anything other than silicone. Mapesil made by Mapei and Latisil made by Laticrete are two options for colour matching to your grout. This small detail makes or breaks your shower and needs to be considered before waterproofing starts.
It's nearly impossible to maintain a uniform gap if the corners in the walls of the shower are not straight. This method is guaranteed to outlast surface applied silicone by many years, and you'll appreciate it each time you clean your shower.