Why mould keeps coming back after redecoration

What has to happen before the paint

Active mould is treated with an appropriate fungicidal wash and left to work, then thoroughly rinsed off. Any source of the moisture feeding it, whether that is condensation from poor ventilation, a cold bridge or an external leak, needs identifying, because paint cannot lower humidity or fix a cold wall.

• Affected surface treated and cleaned before any coating touches it
• Ventilation and cold-bridging checked, not assumed to be fine
• Previous paint layers assessed for whether they are trapping moisture

Choosing a system suited to the room

In bathrooms, kitchens and other high-humidity rooms we specify coatings designed to resist mould growth on the film surface, which buys time even where ventilation is imperfect, but this is a supporting measure rather than a substitute for fixing the humidity itself.

Being honest about what paint can and cannot do

We will say clearly if a room's ventilation needs attention before redecoration is worth doing, because painting a room that generates the same humidity every winter is a short-term fix at best. Clients sometimes prefer to proceed anyway and understand the trade-off.