Diagnostic guide
Damp after rain
Find out why internal damp worsens after rainfall and how Quay Point Plastering investigates likely entry routes.
Why diagnosis matters
Treat the cause, then repair the damage
A clear relationship with rainfall is valuable diagnostic evidence. The visible patch may sit below a failed gutter, beside a window, around a chimney or along a route hidden within the wall.
Technical review
Dan, Director / Surveyor
Last reviewed: July 2026. Advice is general until the property, access and visible evidence have been assessed.
Guarantee & aftercare
Written guarantee terms are matched to qualifying work, with inclusions, exclusions and aftercare explained before acceptance.
What we consider
Possible causes and lookalikes
Rainwater goods and roof junctions
Pointing, masonry and render defects
Openings, seals and cavity bridges
Ground drainage and splashback
Inspection method
A clear work sequence
Step 1
Review timing and exposure
Step 2
Inspect internal pattern
Step 3
Check accessible external defects
Step 4
Set a repair-and-drying sequence
Scope boundaries
Honest about what the work does—and does not—cover
High-level access, invasive cavity work, roof repair and drainage excavation are separately scoped or referred.
Common questions
About damp after rain
Can the water travel inside the wall?+
Yes. Water can move along cavities, joists and finishes before appearing. The nearest visible defect is not automatically the cause.
Should I paint over the patch?+
Not until the source is corrected and the substrate has dried. Early sealing can hide evidence and lead to repeat failure.
Can damp be diagnosed from photographs?+
Photographs can help us triage an enquiry, but they cannot confirm the moisture source. A site inspection allows the building context, weather exposure, ventilation and accessible materials to be considered together.
Related services
Continue your investigation
Next step
Claim your complimentary survey before choosing a treatment
Tell us what you can see, when it changes and where the property is. Photographs can help us triage the next step.