A seam between a tiled area and another surface is a point of potential weakness, because grout can crack, or water seepage can cause damage to areas under tiling, including floors and ceilings. Silicone sealant reduces the risk of such damage. It is waterproof and flexible, so it will not crack, and it is easily removed for access to concealed areas, such as the underside of a bathtub. Silicone fumes can be harmful, so open a window to keep the working area well ventilated.

Where to Seal
Apply a waterproof seal to any area where tiling meets a bathtub, sink or countertop, and around the outer edge of a shower cubicle panel. You can also use sealant when installing flooring to waterproof areas where tiles meet a hard floor. This prevents water from seeping into or beneath a floor.

Step 1

Using Silicone Sealant

Apply masking tape 1/8 in (3 mm) from each side of the seam (Image 1). This will ensure that the sealant will have straight edges when finished. Cut the nozzle of the sealant tube at an angle, so that the diameter of the opening is slightly wider than the gap that needs sealing. Follow the instructions supplied to load the sealant tube into the dispenser.

Pressing evenly, squeeze sealant into place, moving slowly along the joint. Apply a little at a time, so you can smooth it as you work (Image 2).

Use paper tissues to remove any excess sealant from the nozzle. Smooth the sealant as you work by running a wet finger along the joint (Image 3).

Remove the masking tape to reveal a straight sealant band along the extent of the seam (Image 4).

If necessary, smooth over the sealant once more, pressing gently to avoid spreading it beyond the neat edges created by masking (Image 5).

Step 2

Sealing and Unsealing a Bath Access Panel

A removable panel is needed for access (Image 1), but it still needs waterproofing like any other tiled surface to avoid leaks.

Carefully apply sealant to the seam between the panel and the fixed tiles, trying to keep the seam invisible, if possible (Image 2).

To access the cavity, carefully use a utility knife to cut away the silicone sealant (Image 3). The panel will then pull free.

After replacing the panel, apply silicone sealant again to the joints between the panels, by repeating the steps shown here (Image 4).

Step 3

Other Ways to Seal Tiles

Grout Protector (Image 1)
Simply applied with a brush, this is an option that can help to create a harder-wearing surface.

Tile Sealant (Image 2)
Follow the manufacturer’s advice on the selection and application of sealant for natural tiles.