Aethos advice
Damp or condensation: what to check before painting
Staining, mould and blistering may look similar at first glance, but their patterns and timing can point in different directions. A decorator can record warning signs; the underlying building diagnosis may need another professional.
By Aethos Studio · Published
Record location, season and timing
Photograph the area and note when it worsens. Surface mould at cold corners, marks below a gutter, a patch beside plumbing and salts near ground level are different patterns. Furniture position, ventilation, heating and recent weather provide useful context without proving the cause by themselves.
Condensation forms at cold surfaces
Indoor moisture can condense where surface temperature is low, often around corners, reveals and behind furniture. Cleaning and repainting alone will not change the moisture load, ventilation or thermal bridge. Recurrence should prompt attention to how the room is heated, ventilated and used.
Water entry needs repair before decoration
Defective roofs, rainwater goods, joints, seals or plumbing can wet the building fabric. The source should be repaired and drying allowed before coatings are reinstated. Concealed leaks, electrical risk or significant deterioration require the appropriate trade or building professional.
Do not diagnose from one meter reading
Handheld moisture meters can be useful comparative tools, but materials, salts and meter type affect readings. A number without construction context is not a complete damp diagnosis. Persistent or unexplained moisture deserves an independent, appropriately qualified assessment.
Painting should wait for a stable substrate
The surface must be sound and suitable for the proposed system. Active mould, salts, soft plaster or blistering need more than cosmetic preparation. Once the cause has been addressed, residual staining can be isolated with a compatible system where appropriate.
Write exclusions as clearly as inclusions
A decorating quotation should describe preparation and coating while identifying moisture investigation or building repair outside its scope. That prevents a new finish from being mistaken for a guarantee against unresolved damp, movement or leaks.
Read The Aethos Standard