Mould around a bath, shower, sink or window is a sign that moisture is hanging around. The lasting fix is two-part: deal with the mould safely, then sort out the damp or failed joint that let it take hold.
1. Find and fix the moisture first
Check for leaks, failed sealant, poor ventilation and condensation. Drying the room after use and improving airflow can help reduce recurring damp. If you suspect a leak or the affected area keeps coming back, fix the underlying problem rather than covering it over.
2. Clean existing mould safely
Use a mould-cleaning product that is suitable for the surface, and follow its label, including any protective equipment and ventilation instructions. Never mix cleaning chemicals. Don’t apply fresh sealant over mould: it won’t remove the growth underneath, and the new joint may not bond properly.
If the mould covers a large area, keeps returning, or may be linked to a hidden leak, get the cause assessed before resealing.
3. Reseal only once the surface is clean and dry
Remove failed sealant carefully, prepare the joint as directed by the sealant maker, and let the area dry fully before applying a new bead. Choose a product suited to the material and the joint, then follow its instructions for application and curing.
Products from the Ace Fixings range
Sista Sanitary Silicone 280ml is made for damp areas such as bathrooms, kitchens and showers. Its product information describes it as antimould and notes that it contains a fungicide, making it a suitable choice for sealing compatible sanitary joints after the area has been cleaned and prepared.
Unibond Seal & Bond White Mould Resistant Sealant 389g is a mould- and weather-resistant sealant and adhesive for a broader range of indoor and outdoor joints. Its product information highlights bathrooms and showers where mould resistance is needed and silicone may not be suitable. Check the manufacturer’s guidance for the surfaces and application you have in mind.
These products help seal and protect a suitable joint; they are not mould removers. Clean the affected area and address the moisture source before resealing.
Quick checklist
- Find and fix leaks or persistent condensation.
- Clean mould with a suitable product, following its label.
- Never mix cleaning chemicals.
- Remove failed sealant and let the joint dry before resealing.
- Choose sealant for the surface and use, and follow its instructions.