Cleaning treats the symptom
Mould is a living growth that feeds on moisture. Sprays, wipes and mould-resistant paints remove or suppress what you can see — but they do nothing about the damp surface conditions the mould needs to grow. If those conditions remain, spores that are always present in the air simply recolonise the same spot. That is why the mould comes back to the same corner, the same window reveal, the same wardrobe wall.
The conditions mould needs
Persistent mould almost always traces back to one or more of:
- High relative humidity — everyday moisture from cooking, bathing, drying clothes and breathing with nowhere to go
- Cold surfaces — uninsulated external walls, corners, lintels and window reveals where condensation forms
- Thermal bridging — localised cold spots where the building's insulation is interrupted
- Insufficient ventilation — extract fans that are missing, underpowered or switched off, and sealed-up background vents
- Water ingress or plumbing defects keeping a section of structure persistently damp
The pattern tells the story
Mould high in room corners and around windows usually speaks to condensation and cold bridging. Mould tracking a patch that darkens after rain suggests water ingress. Mould behind wardrobes on external walls is typically still air plus a cold surface. Noting where it appears, when it is worst and how quickly it returns after cleaning is genuinely useful diagnostic information.
Breaking the cycle
Lasting mould control follows a sequence: identify the moisture source, control the underlying conditions, remediate the affected areas properly, and put preventative measures in place. A mould and moisture assessment establishes the first two; cleaning alone never gets past step zero.
Need this looked at properly?
If this sounds like your property, a proper investigation will tell you which cause you're actually dealing with.