How to Remove Mould from Silicone Sealant Around Baths

Mould on silicone sealant is a stubborn, unsightly problem in many bathrooms. That black speckling around the bath or shower tray seems to appear overnight, and once it takes hold, scrubbing alone won't shift it. The good news is you don't need harsh bleach to get your sealant looking fresh again. With a few eco-friendly ingredients and a little patience, you can lift the mould, kill the spores, and keep it from returning.

Why Mould Grows on Silicone (and Why Bleach Isn't the Answer)

Silicone sealant is slightly porous, and in a bathroom it stays damp for long stretches. Mould spores are everywhere in the air, and when they land on a moist, warm surface, they settle in. The black staining you see is the mould's root system — called mycelium — burrowing into the silicone. Surface cleaning only removes the top layer, which is why mould often returns within days.

Bleach-based products can lighten the stain, but they don't always kill the roots. They're also harsh on your lungs, skin, and the environment. Bleach can damage silicone over time, causing cracks that give mould more places to hide. For a gentler, longer-lasting solution, choose a bleach-free paste or a specialist eco cleaner.

Your Eco-Friendly Mould-Removing Toolkit

You probably already have most of what you need. Collect:

• Bicarbonate of soda — a mild abrasive that lifts surface mould.
• White vinegar — acidic, and effective at killing common mould species.
• Hydrogen peroxide (3%) — a natural antifungal that helps break down stains.
• Tea tree oil or clove oil — strong antifungal properties; a few drops go a long way.
• An old toothbrush and a spray bottle.
• Microfibre cloths and a squeegee.

If you'd rather not mix your own, look for a specialist bleach-free mould cleaner. Check the label for plant-based surfactants and avoid anything that says chlorine bleach.

How to Remove Mould with a Bleach-Free Paste or Specialist Cleaner

For light to moderate mould, mix three tablespoons of bicarbonate of soda with enough water to form a thick paste. Add five drops of tea tree or clove oil and stir well.

Dry the silicone first, then apply the paste along the sealant. Press it gently into the crevice where the silicone meets the tile or bath. Leave for at least 30 minutes — longer for stubborn black spots.

Spray with white vinegar — it will fizz and help loosen the mould. Wait five minutes, then scrub along the sealant with an old toothbrush. Don't scrub too hard; you want to lift the mould, not damage the silicone. Wipe away the paste with a damp cloth, then rinse with clean water.

If the mould is deep, use a specialist eco cleaner. Apply as directed, leave for the full recommended time, then wipe. Repeat over several days if needed. If the silicone is cracked or black all the way through, replace it — no cleaner will fix that.

Drying and Sealing to Stop Regrowth

Once the mould is gone, drying is the single most important step. Mould needs moisture, so if you keep the silicone dry, you starve it. After every bath or shower, use a squeegee to remove water from the tiles and the sealant. Then leave the door or window open for at least 20 minutes, or run the extractor fan.

You can also apply a thin layer of eco-friendly silicone protector or wipe with white vinegar once a week. Vinegar leaves an acidic film that mould dislikes. Avoid leaving wet towels or bath mats pressed against the sealant — they trap damp. Check for leaks around the bath or shower tray; even a slow drip keeps silicone permanently wet.

Everyday Habits to Keep Silicone Mould-Free

Prevention is easier than removal. A few small habits will keep your bathroom fresher for longer:

• Ventilate daily. Open a window or run the fan after every shower.
• Squeegee after use. It takes 30 seconds and makes a huge difference.
• Wipe the sealant with a dry cloth once a week.
• Spray white vinegar on the silicone weekly, then leave to dry.
• Fix leaks promptly. Dripping taps keep the area damp.
• Wash bath mats and towels regularly, and hang them to dry.

With a little consistency, your bath's silicone can stay clean, clear, and mould-free — no bleach required. Your bathroom will look brighter, smell fresher, and your lungs and the planet will thank you.