How to Identify and Treat Mould Before Repainting Walls
                      How to 
Identify 
and Treat 
Mould 
Before 
Repainting 
Walls
Repainting walls can freshen any 
space. Yet mould hiding beneath 
the surface can undo all that 
effort. If it is not treated first, it 
will return. New paint may peel, 
stain, or smell musty within 
months. Knowing how to spot 
mould early and deal with it the 
right way saves time and money.
How to 
identify 
mould on 
walls
Mould isn’t always easy to spot. It can appear as 
black, green, or brown patches, often in corners, 
near windows, or behind furniture. Sometimes 
the signs are subtle, such as bubbling or flaking 
paint, damp or cold walls, or a musty smell. 
Bathrooms, kitchens, poorly ventilated rooms, 
and exterior walls are common problem areas. 
Before repainting, inspect walls carefully, 
especially edges and corners. If mould keeps 
returning, there is likely an underlying moisture 
issue.
Why mould appears before 
painting
Mould grows where moisture lingers. Leaks, 
condensation, rising damp, or poor airflow create 
the perfect conditions. Painting over mould traps 
moisture inside the wall. This allows spores to keep 
spreading under the paint film.
Many people assume fresh paint will seal the 
problem. It does not. Without fixing the cause, 
mould will break through again. This is why 
treatment always starts with moisture control.
1. Fix the moisture source
Look for leaks in pipes, roofs, or window frames. Improve ventilation where 
steam builds up. Open windows regularly or use extractor fans. For exterior 
walls, check gutters and drainage paths. Walls must stay dry before any 
painting begins.
2. Clean the affected area properly
Wear gloves and a mask before cleaning. Use a suitable mould-cleaning 
solution and scrub the surface gently. Avoid dry brushing, as this can 
release spores into the air. Rinse the wall with clean water and allow it to 
dry fully. This step may take longer than expected, but rushing it leads to 
failure later.
3. Prepare the wall surface
Once dry, sand the area lightly. This removes residue and helps new 
coatings bond well. Wipe away dust with a damp cloth and let the 
wall dry again. The surface should be clean, smooth, and moisture-
free before painting.
Steps to treat mould before repainting
Using the correct products makes a real 
difference. A mould-resistant primer 
helps block spores left in the surface. For 
high-risk rooms, applying an 
antifungal paint on walls can reduce 
future growth. These coatings are 
designed to resist humidity and slow 
mould development over time.
For living spaces where appearance 
matters, finishes like acrylic matt 
emulsion offer a clean look while allowing 
walls to breathe. This balance helps 
reduce trapped moisture.
4. Choose the right paint 
system
Preventing mould 
after repainting
Prevention does not stop once the paint 
dries. Keep rooms well ventilated. Avoid 
placing furniture tight against cold walls. 
Wipe away condensation when it appears. 
Regular checks help catch small issues 
before they spread.
In older buildings, walls may need ongoing 
care. Paint alone cannot solve structural 
damp problems. Treating mould should 
always be part of a wider plan to manage 
moisture.
Conclusion
Repainting works best when it goes 
beyond surface fixes. Treating mould 
properly helps walls stay clean and 
strong over time. The right finish also 
plays a role. For everyday interiors, 
acrylic matt emulsion offers a neat 
look while allowing walls to breathe. 
When care and material choice come 
together, painted spaces remain fresh 
long after the job is done.
Thank You