Outside the property
Many damp problems start outside, so the surveyor should look at the outside before the inside.
- Ground levels, paths and patios against the walls compared with the damp proof course
- Gutters, downpipes and drains for leaks or overflow
- Brickwork, pointing, render and window sills for cracks that let rain in
- Air bricks and subfloor ventilation, which should be clear and not blocked
Inside the property
- The pattern and height of any damp, staining, salts or mould
- Moisture readings across affected and unaffected walls for comparison
- Air humidity and surface temperatures to check for condensation
- Skirting boards, floors and accessible timbers for rot or woodworm
- Ventilation in kitchens and bathrooms
How moisture is measured
Electrical moisture meters are useful for mapping where damp is, but salts and some wall finishes can give misleading readings. Where the cause is not obvious, a surveyor can take small samples from the wall to measure the moisture in the masonry itself and test for salts. This is what separates a diagnosis from a guess.
What your report should include
- The cause of the damp in each affected area, not just the meter readings
- Recommended work, with the reason for each item
- Any simple fixes you can do yourself, such as lowering ground levels or clearing gutters
- Photos of the problem areas
- Details of any guarantee offered on the proposed work
Common questions
How long does a damp survey take?
For a typical house, an inspection takes around one to two hours depending on the size of the property and how many areas are affected.
Do I need to be there?
It helps. You can point out where the problems are, when they are worst and any history of leaks or past treatment.
What should I do before the survey?
Avoid redecorating or covering affected areas, and pull furniture away from damp walls if you can so the surveyor can see them.