Spend over £100 (ex. VAT) for FREE Delivery

Customer Support 0800 22 77 77

Near You - Local Branches Nationwide

Mastering Mould Removal: Bathroom Silicone Sealant Cleaning Guide

Mastering Mould Removal: Bathroom Silicone Sealant Cleaning Guide

Black mould on silicone sealant can be both unsightly and unhealthy. But what causes this black mould to develop, how can you remove it, and can it be prevented? This blog aims to answer all these questions and help you master mould removal.

What is Silicone Sealant Mould?

Silicone sealant is an adhesive which creates a waterproof barrier between tiles, floors, appliances, and other bathroom furniture. This sealant is usually exposed to high volumes of moisture and condensation, which in turn can cause black mould to develop.

What are the Causes of Silicone Sealant Mould?

There are a few reasons why your silicone sealant becomes mouldy:

High levels of moisture

If a room is constantly damp, it is more likely to develop black mould. Kitchens, bathrooms, and ensuites are all areas which have consistent high levels of humidity and are therefore more prone to mould.

Damaged silicone

If your silicone sealant is old, split, or cracked, it loses its waterproof properties and water can penetrate the barrier. Once water is behind the silicone mould will start to develop.

Lack of cleaning

If a wet surface and silicone sealant is not wiped clean after use it will increase the chances of mould developing.

Steps to Removing Mould

If you already have mould on your silicone sealant, do not despair; there are a few ways to remove it.

Specialist cleaning products

You can buy specialist cleaning products that are designed to remove black mould. However, ensure that you buy a product that is specifically designed for silicone sealant and always read the manufacturer's instructions before you use.

Homemade solution

Combine one cup of white vinegar with two or three teaspoons of baking soda and mix into a paste. Apply a thick layer of this paste to the silicone sealant and leave for around five minutes. Use a stiff-bristled brush – an old toothbrush would work – to gently scrub the

mould away. Do not be too enthusiastic as silicone is quite delicate. Use a clean, wet sponge to rinse the silicone clean.


If the above method doesn’t work and there are still stubborn patches of mould on your silicone, you can use a combination of bleach and water. Mix one part bleach to four parts water and spray liberally over the silicone sealant. Leave it to evaporate before wiping off with a sponge and cool water and drying with a clean towel or microfibre cloth.

Remove and renew

If all else fails, you may need to remove the damaged, dirty silicone sealant and replace it with new. If you are unsure how to approach this, it is always worth asked a professional for advice, so you do not damage any surrounding tiles, floors or appliances.

How to Prevent Mould

Prevention is always better than cure, and there are a few simple things you can do to help prevent the build up of mould on your silicone sealant.


Ventilation is extremely important in the prevention of mould, particularly in bathrooms. Always use a fan when in the shower or bath, and if you do not have an extractor fan, open a window to allow for natural ventilation.

Dyring clothes outside and regularly washing towels, bathmats and shower curtains, can also help to reduce moisture in the home and prevent mould from developing.

Regular cleaning

Wiping down damp surfaces and ensuring water is not left standing will help to create a drier environment. Cleaning away residue, such as soap, shampoo, or washing liquid, will also help to prevent the growth of mould on your sealants.

Use high-quality sealant

When first installing your silicone sealant, it is a good idea to choose the best your budget will allow. The higher the quality, the more effective waterproof barrier it will create, preventing water seepage and helping to avert mould.

Explore Our Bathroom Sealants

Here at National Plastics we offer a range of sealants that are perfect for every project. For further information and guidance on the best sealant for you, call our expert team today on 0800 22 77 77.

National Plastics is a trading name of Specialist Building Products Limited, a wholly owned subsidiary of the Epwin Group Plc. Specialist Building Products Limited is registered in England & Wales. Company Registration number: 1268689. Registered Office: Friars Gate, 1011 Stratford Road, Shirley, Solihull, West Midlands B90 4BN. VAT Registration No. 864 4507 10