Step-by-Step Guide:

1. Remove the Old Silicone Sealant

• Cut the old silicone: Use a utility knife or silicone scraper to carefully slice through the old silicone. Try to cut both along the edges where the silicone meets the tiles or other surfaces and down into the sealant. Take your time with this, as rushing could damage your tiles or surfaces.
• Peel off the silicone: Once you’ve cut the sealant, peel away the old silicone using your fingers or a plastic scraper. Sometimes it may come off in chunks, while other times it may need a bit more force to remove.

2. Clean the Surface

• Remove debris: Once the silicone is gone, you may notice some residue left behind. Use a plastic scraper or utility knife to remove as much of the leftover silicone as possible.
• Clean the area thoroughly: Use rubbing alcohol or vinegar and a clean cloth to wipe down the surface. This will remove any leftover residue, grime, and soap scum. The surface must be clean and dry before you apply the new silicone.
• Dry the area: Make sure the area is completely dry before proceeding. Silicone does not adhere well to wet surfaces.

3. Prepare the New Silicone Sealant

• Choose the right silicone: Pick a mould-resistant, bathroom-specific silicone sealant. It’s ideal for areas like showers or sinks because it helps prevent mould and mildew growth.
• Prepare the caulk gun: If your silicone comes in a tube that requires a caulk gun, load it into the gun and cut the nozzle at a 45-degree angle. The size of the cut will determine the thickness of the bead. A smaller cut is recommended for precision.

4. Apply Painter’s Tape (Optional)

• Tape off the edges: If you want a clean, straight line, apply painter’s tape to the edges of the area where you’ll be applying the silicone. This will help you achieve a neat finish and prevent silicone from getting on the surrounding surfaces.

5. Apply the New Silicone

• Start at one end: Hold the silicone tube at a 45-degree angle to the surface and slowly squeeze the caulk gun, applying a continuous bead of silicone along the joint where the old silicone was removed.
• Move steadily: Keep the pressure even as you move along, making sure the silicone fills the entire gap. You can pause to make sure you’re getting a consistent amount of silicone.

6. Smooth the Silicone

• Smooth with a tool or finger: Once the silicone is applied, you can smooth it out using a silicone smoothing tool or your finger (wet your finger to prevent it from sticking to the silicone). This will ensure that the silicone seals properly and gives it a nice, professional finish. Remove any excess as you go.

7. Remove the Painter’s Tape

• Peel off the tape: Before the silicone starts to set, carefully remove the painter’s tape along the edges to leave a clean, sharp line. Do this while the silicone is still wet, as it can be harder to remove once it’s dried.

8. Let the Silicone Cure

• Wait for it to cure: Follow the manufacturer’s instructions for curing time, which typically ranges from 24 to 48 hours. Don’t expose the new silicone to water or moisture until it’s fully set.
• Ventilate the room: Ensure that the bathroom is well-ventilated to speed up the drying process and prevent mold growth.

9. Clean Up

• Clean tools: Immediately clean your tools (caulk gun, smoothing tools, etc.) with a damp cloth before the silicone dries on them.
• Remove any excess silicone: If any silicone has gotten on the surrounding surfaces, clean it up while it’s still wet using a damp cloth.

10. Maintain the New Silicone

• Prevent mould growth: Keep the area as dry as possible to prevent mould from forming in the future. If you notice any buildup, clean it off immediately to prolong the life of your new sealant.

And that’s it! You’ve successfully replaced your old, mouldy bathroom silicone with a fresh new layer. Enjoy your mould-free bathroom!