Damp and mould on walls: how to tell the types apart

What do the signs point to?

• Condensation: sweating on glass and cold external wall surfaces in the morning; black or green mould around bathrooms, kitchens and window edges
• Leak: wetness on ceilings and in corners, especially on upper floors and under the roof; a stain that grows after rain
• Walls in contact with the ground: wetness on basement and ground-floor walls, plaster blistering and flaking
• General signs: blistering paint, a musty smell, swollen wooden doors and furniture, laundry that dries slowly

Simple and safe checks

The sources do not describe a test that separates wall damp into types; the practical approach is this: does the damp increase after rain, does it appear only on cold external walls in winter, or is it concentrated at basement or ground level? These three observations narrow the cause; the exact diagnosis is made during the survey by moisture measurement.

The target mentioned in Cumhuriyet is to measure indoor humidity with a hygrometer and try not to let it exceed 60 percent. It is a recommendation with no stated source; guides give around 50 percent as a comfort example.

Solutions by type

• Condensation: daily cross-ventilation (10-15 minutes in the source), bathroom and kitchen extractor fans, drying laundry outside, a dehumidifier if needed; for a lasting solution, the adequacy of external wall and window insulation
• Leak: first find and eliminate the source (roof, facade, leak)
• Wall in contact with the ground: areas that need waterproofing include walls in contact with the foundation, the ground floor slab and wet areas
• Mould cleaning: vinegar or a mould remover is used; without removing the source, cleaning is temporary

Health and the limits of paint

Sources report that mould and damp can trigger respiratory problems, asthma and allergies, and that the risk is higher in children, the elderly and people with weak immunity. Because these claims appear in the sources without a reference to an expert organisation, they should be read as a general warning rather than a definitive medical finding; we could not read the World Health Organization text in this work.

If the cause of damp continues, it will blister again as moisture builds up under new paint; so the cause must be removed before refreshing the surface.