Property fixes and removals
Damp survey: getting an independent, neutral assessment
A damp survey identifies what is actually causing damp in a property, whether condensation, penetrating damp, a leak or genuine rising damp. The neutral point is that a survey by someone who does not also sell the treatment protects you from unnecessary work. A good survey is the step that saves money before you commit to any damp proofing.
Not sure what it is yet? Read the full guide to is it really rising damp, condensation vs rising damp and the signs on our sister site HomesAndHedge. This page focuses on the cost, the survey and getting it fixed.
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Get matchedWhat it is
A damp survey diagnoses the cause of damp. That matters because the cheapest and most effective fix is often ventilation or a repair, not the chemical damp-proof course that some firms default to recommending.
This page is about getting a fair, independent diagnosis. For telling condensation from rising damp and reading the signs yourself, see the HomesAndHedge guide linked below.
The survey and the work
A good surveyor inspects the property, takes readings, looks at the construction and history, and works out the actual cause: condensation, penetrating damp from a defect, a plumbing leak, bridged damp proofing or, less often than people assume, true rising damp.
The surveyor then sets out what is genuinely needed. The most important distinction is between a firm that surveys and sells the treatment, and an independent surveyor whose advice is not tied to selling you a damp-proof course.
For mortgage purposes, the report should clearly state the cause, the recommended action and whether any work is needed before the property is suitable security.
Cost
- Independent damp survey
- Get a quote An independent chartered surveyor is not selling you the treatment, which is the neutrality point.
- Free vendor survey
- Often free, but tied A free survey from a firm that also sells the treatment is rarely neutral; treat its recommendations with care.
The genuinely independent option is usually paid, while a free survey often comes from a firm that profits from the treatment it recommends. We hold off quoting figures because they vary; the principle is to value neutrality over a free survey with a built-in sales motive.
Who it is for
- Homeowners with damp who want to know the real cause before spending money on treatment.
- Buyers or sellers where a mortgage valuer has flagged damp and asked for a specialist report.
- Anyone quoted for a chemical damp-proof course who wants an independent second opinion first.
The mortgage and sale angle
- A mortgage valuer who notes damp will often ask for a specialist damp report, and may recommend a retention until it is resolved, so a clear survey is what releases the funds.
- The neutral wedge here is real: the Property Care Association itself cautions against over-diagnosis, so an independent survey that rules damp proofing in or out protects you from paying for work you do not need.
- A report that states the cause and the recommended action is what reassures a lender and a buyer, far more than a sales quote for treatment.
How to choose a vetted specialist
- For a genuinely neutral diagnosis, consider an independent RICS chartered surveyor who does not sell damp treatment.
- If you use a specialist firm, prefer a Property Care Association (PCA) member and be alert to recommendations that default to a chemical damp-proof course.
- Ask the surveyor to state the cause and whether any work is genuinely needed, and get a second opinion before committing to costly treatment.
Frequently asked questions
Do I need a chemical damp-proof course?
Often not. Much diagnosed damp is condensation or penetrating damp, which a damp-proof course does not fix. An independent survey identifies the real cause first. Because some firms survey and sell the treatment, a neutral second opinion can save you unnecessary cost.
Should I use a free damp survey?
A free survey usually comes from a firm that also sells the treatment, so its recommendations are not neutral. It can still be useful, but for an unbiased diagnosis consider an independent chartered surveyor who is not selling you a damp-proof course.
What does a mortgage lender need on damp?
If a valuer flags damp, the lender often asks for a specialist report stating the cause and recommended action, and may hold a retention until resolved. A clear, independent report is usually what lets the mortgage proceed.
Sources
Editor, Sorted Property
Oliver leads Sorted Property's editorial coverage of UK home services. He researches and writes the plain-English guides that help homeowners choose between installers and trades, drawing on the standards set by bodies such as MCS, TrustMark, the Energy Saving Trust and the Property Care Association, and is clear about what to check before any work starts.
Last reviewed: 11 June 2026