Damp Proofing Cost UK 2026: DPC Injection and Treatment Prices
Damp proofing costs £70-£120 per linear metre, or roughly £1,000-£3,000 per property in 2026. See the prices, the replastering trap, and how to check the diagnosis is even right.
Damp proofing is one of the few trades where the first question is not "how much" but "do I even need this". Rising damp is over-diagnosed, "free surveys" are often sales visits, and the replastering that makes the treatment work is frequently left off the quote. Here are the 2026 prices and how to check both the diagnosis and the quote.
Quick cost summary
| Treatment | Typical cost |
|---|---|
| Chemical DPC injection | £70-£120 per linear metre |
| Whole terrace | £1,000-£1,800 |
| Whole semi | £1,500-£2,200 |
| Whole detached | £2,500-£3,000+ |
| Replastering after treatment | £30-£70 per m² |
Prices based on UK trade averages and MyBuildAlly quote analysis, mid-2026. Replastering is frequently quoted separately and can match or exceed the injection cost.
First: is it actually rising damp?
This matters more than the price, because the wrong diagnosis means paying for a treatment that will not fix anything.
Genuine rising damp is far less common than the number of chemical DPCs sold would suggest. Damp at low level is often caused by something else entirely: condensation, a leaking gutter or downpipe, a bridged DPC (render or a flower bed carrying moisture over the existing barrier), or external ground levels that are too high. None of these is fixed by injecting a chemical DPC. Before you pay for treatment, rule these out, ideally with an independent damp surveyor rather than the company selling the cure.
A "free damp survey" from a firm that sells damp proofing has an obvious incentive to find rising damp. That does not make every diagnosis wrong, but it is a reason to get a second opinion before committing. Our guides on checking a DPC and what a DPC should look like help you understand what you are being told.
The replastering trap
If a chemical DPC is genuinely needed, the injection is only half the job.
After injection, the salt-contaminated plaster usually has to be hacked off to a certain height and re-rendered with a salt-resistant mix, then skimmed. This replastering can cost as much as the injection. A quote that covers only the injection, at a tempting price, has left out the part that actually makes the wall usable again. Always confirm whether replastering is included, and to what height.
What a fair damp proofing quote includes
- A clear diagnosis of the cause, not just "rising damp"
- The treatment method and the length of wall treated (in linear metres)
- Whether replastering is included, and to what height
- The salt-resistant render specification
- A guarantee, and whether it is insurance-backed (so it survives the company closing)
- What is excluded (decoration, skirting boards, flooring)
The guarantee question
Damp treatment usually comes with a long guarantee, but a guarantee is only worth as much as the company behind it. Ask whether it is insurance-backed, which means an independent insurer honours it if the original firm stops trading. An unbacked 20-year guarantee from a small firm is worth little if they disappear.
Check your damp proofing quote
Damp is a trade where over-diagnosis and missing replastering quietly inflate the real cost. Upload your quote and we check it against the benchmarks above, flag when the replastering or a clear diagnosis is missing, and help you see whether the price is fair before you commit. It takes under a minute.
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