Searching for damp proofing near you turns up two quite different businesses under one description. One of them surveys damp and sells you nothing; the other surveys damp and sells you the remedy. Both have a place, and the mistake is not knowing which one has just been in your house. The free survey is a sales visit and is worth having; it is simply not an independent second opinion on whether the work is needed at all.
What a competent damp survey actually does
It reads the outside of the building before the inside: ground levels against the damp course, gutters and downpipes, pointing, air bricks, and whether a path or a flower bed has been built up over the years. Then it reads the inside, with a moisture meter as one instrument among several rather than as the verdict. A meter on a plastered wall responds to salts as well as to water, which is why a reading on its own proves very little and a surveyor who quotes one at you has skipped the argument.
The questions that sort one firm from another
Ask what else could produce this pattern and why it has been ruled out. Ask what the plaster removal height is and how it was arrived at. Ask who underwrites the guarantee and whether it covers the replastering as well as the injected course. A firm that answers all three without hesitation is a firm that has done the diagnosis; a firm that moves straight to a price for a chemical course has decided the answer before it arrived.
Local knowledge is worth more here than in most trades
Damp is a function of how a place was built and what the ground does. A contractor who works a single city knows which streets have cellars, which estates were built with a slate course and which with none, and where a raised pavement has buried the course on a whole terrace. That is not marketing: it changes what they look for first, and it is a fair reason to prefer a genuinely local firm.
Questions people ask about damp proofing near me
Should I pay for an independent damp survey?
If the remedy quoted is expensive, yes. An independent damp and timber surveyor charges a fee and does no remedial work, so their conclusion that you do not need a damp course costs them nothing. That is precisely what makes it useful.
Are damp proofing guarantees worth anything?
Only as far as the firm and its insurer are. Ask whether the guarantee is insurance backed, which failure it covers, and whether it transfers to a buyer. A twenty year guarantee from a firm without an underwriter is a promise, not a product.
How many quotes should I get?
Three, and read them as diagnoses rather than as prices. If two of them find the same cause and one does not, that disagreement is the most valuable thing you have, and it is worth resolving before anybody starts hacking off plaster.