The right treatment for damp depends entirely on accurate diagnosis. Rising damp, penetrating damp, and condensation can all produce similar surface signs, but each has a different cause and requires a different fix. Without a proper assessment, treatments are applied to the wrong problem and the damp returns.
To identify damp correctly, a professional survey looks beyond what is visible on the surface and traces moisture back to its source. A trained surveyor uses specialist equipment and a structured inspection process to establish where moisture is coming from and why, then produces a written report with findings and treatment recommendations grounded in evidence, not assumption.
Here is how that process works from start to finish.
A damp survey is a structured inspection designed to identify the source and type of moisture affecting a property. It covers internal walls and plaster, floors and skirting boards, external brickwork, below-ground spaces, and ventilation points, working from the outside of the building inward.
The inspection begins with an external walkthrough. The surveyor checks the condition of the roof covering, guttering, downpipes, masonry, mortar joints, and the level of ground against the building. A bridged or absent damp proof course, blocked guttering, or damaged pointing can all allow moisture to enter, and spotting these defects early directs the rest of the survey.
Government guidance on damp and mould, published by the Ministry of Housing, Communities and Local Government (MHCLG), estimates that between 4% and 27% of homes in England are affected by damp and mould. The guidance also notes that people in rented housing are more likely to live with damp and mould than owner occupiers, which points to how widespread accurate diagnosis needs to be [1].
If there is any uncertainty at the survey stage, a damp proof course repair may be recommended once findings are confirmed.
Visual inspection is essential, but it only tells part of the story. Experienced surveyors use a range of specialist equipment to measure and confirm what cannot always be seen.
The Property Care Association (PCA), the leading professional body for the damp proofing and remedial treatment industry, sets out the equipment used during a thorough damp inspection [2].
According to its guidance, the following points apply:
These tools allow the surveyor to build a picture of where moisture is present, how far it extends, and whether conditions in the property are actively generating damp. Without this data, a diagnosis based solely on appearance carries an enormous risk of error. Once readings are taken and cross-referenced with the visual inspection, the surveyor can draw conclusions about the cause.
If you are ready to get a clear answer on your property, you can book a damp survey and get the process started.
Correctly identifying the type of damp is where the survey pays for itself. Rising damp, penetrating damp, and condensation have different causes, different patterns, and different solutions. Applying the wrong treatment wastes time and money, and rarely resolves the problem.
Rising damp occurs when groundwater rises through masonry by capillary action, usually due to a failed or absent damp proof course. It rises to around 1 metre and leaves a tide mark at low level, typically with salt deposits in flaky plaster, rotten skirting boards, a musty smell, and rusting iron fixings. Penetrating damp enters horizontally through damaged roofing, defective pointing, or a leaking pipe, and can appear at any height, often identified by localised patches and damaged internal decoration.
Bournemouth, Christchurch, Poole (BCP) Council’s guidance on damp and mould notes that condensation is by far the most common cause of damp, particularly in winter. As windows close and heating goes on, the average household generates around 20 pints (11.4 litres) of moisture daily in an unvented property [3].
That’s simply moisture that condenses on cold surfaces when ventilation is insufficient!
A written survey report documents all of this:
For homeowners preparing for repair work, it provides a clear basis for decisions. For buyers and landlords, it is documented evidence of the property’s condition. A reputable surveyor will only recommend work that the findings actually support.
For landlords, that matters beyond good practice. If you are unsure where your responsibilities around damp and mould in a rental property start and end, it’s worth reading into before a survey takes place.
Damp problems persist when the cause is misread. Surface signs are treated, and within months, the same patch returns. A professional survey establishes whether moisture is rising through masonry, entering from outside, or forming through condensation, and that distinction is what allows the right treatment to be applied once.
Croft Preservation has carried out professional property surveys across Dorset and Hampshire since 1985. Our team includes CSRT-qualified surveyors and holds full Property Care Association membership, alongside accreditations from NHBC, SafeContractor, and DELTA Membrane Systems. Every survey is conducted on a survey-first basis, with no hidden costs at any stage.
To arrange a professional damp survey, contact the team today or call 01202 737739.
[1] GOV.UK, Ministry of Housing, Communities & Local Government (MHCLG), Department of Health & Social Care (DHSC), UK Health Security Agency (UKHSA), Understanding and Addressing the Health Risks of Damp and Mould in the Home (2026): https://www.gov.uk/government/publications/damp-and-mould-understanding-and-addressing-the-health-risks-for-rented-housing-providers/understanding-and-addressing-the-health-risks-of-damp-and-mould-in-the-home–2
[2] Property Care Association (PCA), Investigating Dampness: https://www.property-care.org/professionals/guidance/damp/investigation/
[3] GOV.UK, Bournemouth, Christchurch, Poole (BCP) Council, Damp and Mould in Your Home: https://www.bcpcouncil.gov.uk/housing/help-for-tenants/damp-and-mould-in-your-home/the-main-causes-of-damp-and-mould-in-your-home
