Old silicone sealant can become mouldy, cracked or start peeling away over time, making your bathroom or kitchen look tired while increasing the risk of water damage. Although it may seem easier to apply new silicone over the old sealant, this won't create a strong, waterproof bond.

The best solution is to remove the existing silicone completely before resealing. Here's how to do it safely without damaging your tiles or sanitary ware.

What You'll Need

Before you begin, gather the following:

• Silicone sealant remover
• Plastic scraper or sealant removal tool
• Sharp utility knife
• Clean cloths
• Warm soapy water
• New bathroom silicone sealant

Using a dedicated silicone remover will make the job much easier by softening any stubborn residue.

Step 1: Cut Away the Old Silicone

Using a sharp utility knife, carefully cut along both sides of the silicone bead where it meets the bath, shower tray or tiles.

Take your time and use light pressure to avoid scratching the surrounding surfaces.

Step 2: Peel Away the Silicone

Once you've cut both edges, gently pull the silicone away by hand. Most of it should peel away in long strips.

Try to remove as much as possible before moving on to the next step.

Step 3: Remove Any Remaining Residue

Apply a silicone sealant remover to any leftover silicone and leave it for the time recommended by the manufacturer.

Once softened, carefully scrape away the remaining residue using a plastic scraper or sealant removal tool. Avoid using metal tools, as they can scratch tiles, baths and shower trays.

Step 4: Clean and Dry the Surface

Wipe the area clean with warm soapy water to remove any remaining residue.

Allow the surface to dry completely before applying new silicone. A clean, dry surface gives the new sealant the strongest possible bond.

Step 5: Apply Fresh Silicone

Apply a smooth, continuous bead of sanitary silicone around the joint.

For the best results:

• Cut the nozzle at a 45° angle.
• Apply steady, even pressure.
• Smooth the bead immediately using a finishing tool or a damp finger.
• Allow the silicone to cure fully before exposing it to water.

Top Tip: If you're resealing a bath, fill it with water before applying the new silicone and leave it filled until the sealant has fully cured. This helps prevent the seal from stretching or pulling away once the bath is in use.

Common Mistakes to Avoid

• Applying new silicone over old silicone.
• Using metal scrapers that can damage tiles or baths.
• Applying silicone to damp surfaces.
• Using the bath or shower before the silicone has fully cured.

Avoiding these mistakes will help create a neater finish and improve the lifespan of your new seal.

Frequently Asked Questions

Can I apply new silicone over old silicone?

No. New silicone won't bond properly to cured silicone, so the old sealant should always be removed first.

Will silicone remover damage tiles?

Most silicone removers are safe to use on ceramic and porcelain tiles when used according to the manufacturer's instructions. If you're unsure, test the product on a small hidden area first.

How often should bathroom silicone be replaced?

Quality bathroom silicone can last between five and ten years, although areas exposed to constant moisture or poor ventilation may need replacing sooner.

Final Thoughts

Removing old silicone properly is the key to achieving a clean, professional and long-lasting waterproof seal. By taking the time to remove every trace of the old sealant and ensuring the surface is clean and dry, you'll give your new silicone the best chance of lasting for years.

At Silicone Direct, we stock a wide range of silicone removers, sanitary sealants and application tools from trusted brands including Soudal and Bond It, making it easy to find everything you need for your next sealing project.