Replacing a silicone seal in the bathroom: the complete method

A blackened or moldy silicone seal in the bathroom is both unsightly and unhygienic. Replacing it is a job within everyone's reach, taking only an hour and a few simple tools. Here is the complete method for a professional result.

The materials needed

• A tube of sanitary silicone (with mold inhibitor)
• A caulking gun
• A utility knife or a razor blade
• Silicone remover (optional but very useful)
• Masking tape
• A spray bottle of soapy water
• A clean cloth

Step 1: remove the old seal

Cut the old seal with the utility knife, sliding the blade along the surfaces. Then pull the seal in one continuous motion. If it resists, apply silicone remover and let it work for a few minutes. The old silicone must be completely removed: any remaining silicone prevents the new seal from adhering.

Step 2: clean and dry

Clean both surfaces thoroughly (walls and shower tray/bathtub) with a degreasing product. Rinse and dry 100%. Silicone does not stick to a damp or greasy surface: this is the most important step for a long-lasting seal.

Step 3: prepare the surfaces

Stick masking tape on each side of the joint, about 3-4 mm from the corner. This lets you apply a perfectly straight seal, without smears, and remove the excess cleanly.

Step 4: apply the silicone

Cut the cartridge nozzle at a bevel (45° cut). Place it in the gun and apply the silicone pressing evenly on the trigger, moving in one continuous motion along the corner. The bead should be slightly larger than the gap to fill.

Step 5: smooth the seal

Spray your finger with soapy water (silicone does not stick to it) and run it along the seal to smooth it and press it into the corner. Wipe your finger regularly. This is the gesture that produces a clean, even seal.

Step 6: let it dry

Remove the masking tape immediately, before the silicone sets. Let it dry for 24 hours (read the instructions on the tube) before any contact with water. Avoid using the shower during this period.