How to post a damp or mould investigation job
Damp is a symptom, not a single diagnosis. Condensation, plumbing leaks, roof or gutter defects, failed sealant, ground moisture and ventilation problems can create similar stains. A good job post records the pattern and asks for investigation rather than selecting an expensive treatment in advance.
Avoid cleaning or painting the whole area immediately before photographs. You can manage obvious health and safety concerns, but a specialist needs to understand where moisture returns and under what conditions.
Record the location and pattern
- Name the room, wall orientation and floor level.
- Measure roughly how high and wide staining extends.
- Say whether it appears at floor level, around windows, in corners, on ceilings or behind furniture.
- Note whether it worsens after rain, cooking, showering, cold weather or periods when the property is closed.
- Mention musty smells, damaged plaster, peeling paint, salts, mould colour and condensation on glass.
Include the wider property context
State the approximate age and construction type if known, whether the property is detached or attached, and any recent insulation, window, heating or ventilation changes. Mention exterior ground levels, blocked gutters, cracked render, flat roofs, chimney breasts and known plumbing repairs near the affected area.
Ask for cause, evidence and remedy
- What moisture source or mechanism does the inspection indicate?
- What observations or measurements support that conclusion?
- Does another trade need to repair a leak, roof, gutter or ventilation issue first?
- Which proposed work addresses the cause and which work repairs finishes?
- How should the area be monitored after the repair?
Be cautious when a costly treatment is proposed from a photograph alone without questions about the building or moisture pattern. An on-site inspection may be necessary before a reliable scope can be written.
Photograph without losing context
Take a full-wall photograph, a room view and close photographs of the stain or mould. Include the corresponding outside wall, roof edge, gutter or ground level where safely visible. Date the photos and repeat them after rain or cold weather if the pattern changes.
Copyable damp investigation description
Example: 'Investigate recurring damp and black mould in the upper corner of a north-facing bedroom in a 1990s semi in Kildare. It is worst in winter and after heavy rain, returns after cleaning, and extends about 60 cm from the external corner. The room has double glazing and a wall vent. There is a gutter outside near the affected area. Indoor and ground-level exterior photos are attached. I need the likely cause documented and a repair scope, not decoration only.'
Frequently asked questions
Should I ask for mould cleaning or damp investigation?+
When the cause is unknown or the problem returns, ask for investigation first. Cleaning the visible surface alone may not address the moisture source.
What photos help diagnose damp?+
Include the whole wall, room context, close details and the corresponding exterior area. Repeat photos when weather or occupancy changes the pattern.
Should I repaint before the inspection?+
Avoid covering the evidence immediately before an inspection unless necessary for safety. Recent photos can preserve the original pattern if cleaning is required.
Can a specialist diagnose damp online?+
A post can help triage the issue, but similar symptoms have different causes. A reliable repair plan may require an on-site inspection and moisture assessment.
What should the quote separate?+
Ask it to separate investigation, repair of the moisture source, drying time, removal of damaged material and final plastering or decoration.
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