Free damp survey vs independent — what's the difference?
Search for help with damp and you'll be offered plenty of "free surveys". They can be useful — but it's worth understanding exactly what they are before you rely on one.
What a "free survey" actually is
A free damp survey is, almost always, a sales appointment. It's offered by a company that installs damp-proofing systems — chemical injection, tanking, replastering — and its business depends on finding work to quote for. That doesn't make the people dishonest, but it does build in a conflict of interest: the surveyor is incentivised to find a problem that their product happens to solve. It's why so many older buildings end up diagnosed with "rising damp" and sold an injected DPC they never needed.
What an independent survey gives you
An independent damp surveyor charges a fee for the diagnosis and has nothing to sell beyond the report — no treatments, no remediation, no building work. That single difference changes everything:
- The diagnosis is impartial — there's no product the answer has to point towards.
- You often find the cause is maintenance, ventilation or an external defect, not expensive treatment.
- You get a written report you can act on yourself, hand to your own builder, or use to renegotiate a purchase.
How to choose well
Whether you go independent or not, look for a few things: ask up front whether they carry out the remedial work they recommend; check they'll give you a written report rather than just a verbal quote; look for relevant qualifications; and for an older or traditional building, make sure they genuinely understand breathable, pre-1919 construction rather than defaulting to modern fixes.
When each makes sense
If you already know you want a particular treatment and just need a price, a contractor's free survey is fine. But if you actually want to know what's wrong and why — especially before buying, on an older building, or when a previous "fix" didn't work — pay for an independent diagnosis. A modest survey fee is the cheapest decision you'll make if it stops you spending thousands on the wrong cure.