Spotted an unsightly damp patch on your wall? The temptation to grab a tin of white emulsion and paint over it is strong. It’s quick, cheap, and within an hour that stain has vanished.
But this common “quick fix” is one of the most dangerous mistakes homeowners make, according to Dr. Eleni Nicolaou, a home wellness expert at Davincified. Far from solving the issue, painting over active mould creates a “paint-film petri dish” where harmful spores flourish invisibly while you breathe in toxic air.
Dr. Nicolaou explains why this decorating shortcut backfires, and provides the correct protocol for dealing with damp safely.
The Science Behind The Paint-Film Petri Dish
- Lateral Spore Migration
When you paint over mould, you’re not stopping its growth – you’re simply blocking your view of it. Standard emulsion is water-based and breathable enough to let mould continue feeding on moisture trapped in the wall, but thick enough to hide the spreading growth.
“The mould doesn’t simply sit there dormant,” says Dr. Nicolaou. “It travels sideways behind the plaster, infecting a much larger surface area than the original visible patch. You might paint over a dinner-plate-sized stain, only to find months later that the mould has spread across an entire wall section behind your nice clean paint.”
- The Moisture Trap
Paint acts as a seal that prevents walls from breathing properly. This traps the original dampness that caused the mould in the first place, creating exactly the high-humidity environment that allows spores to thrive.
“Think of it like putting cling film over a wet sponge,” Dr. Nicolaou explains. “The moisture has nowhere to go, so it just sits there, feeding the problem. Meanwhile, the wall can’t dry out naturally, which makes the situation progressively worse.”
- The False Sense Of Security
The most dangerous aspect is the health risk. Just because you can’t see black spots doesn’t mean you’re not breathing in mycotoxins being released behind that “clean” white wall.
“Families often tell me they feel unwell, with symptoms like headaches, respiratory issues, and fatigue, but can’t work out why,” says Dr. Nicolaou. “Turns out they’ve painted over the visible mould, so they think the problem is solved. In reality, the air quality in their home is becoming increasingly toxic.”
The Correct Solution
So what should you do instead? Dr. Nicolaou outlines the proper protocol for tackling damp and mould safely:
- Identify The Moisture Source: Is it a leak or condensation? “You can paint over mould a hundred times, but if you don’t fix what’s causing the dampness, you’re wasting your time and money,” Dr. Nicolaou notes.
- Use A Biocidal Wash: Kill spores before decorating. “This step is non-negotiable. You need to treat the area with a proper fungicidal solution and let it dry completely.”
- Choose Anti-Mould Breathable Paint: “There’s a huge difference between standard ‘covering’ paint and anti-mould breathable coatings. Breathable paints allow moisture to escape while containing additives that prevent mould growth.”
Dr. Eleni Nicolaou, home wellness expert at Davincified, commented:
“The quality of our home environment has a direct impact on our physical and mental health, yet so many people are unknowingly living with toxic air because they’ve masked the problem rather than solving it.
“I’ve worked with families who couldn’t understand why they felt constantly unwell – experiencing headaches, breathing difficulties, and low energy. The common thread was always poor indoor air quality caused by hidden mould growth. Once they properly addressed the damp issues rather than covering them up, their health improved dramatically.
“Don’t fall into the trap of thinking a fresh coat of paint is a solution. It’s a temporary disguise that makes the problem worse and puts your health at risk.”