Damp Proofing Cost Calculator
Damp proofing is priced per metre of wall treated, but the number that matters most is the survey. Most "rising damp" turns out to be something else, and a chemical DPC injected into a wall that never had rising damp fixes nothing.
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4 steps. Problem, extent, making good and region.
How this calculator works
Damp treatment is priced per metre of wall, or per square metre for tanking. But the price is the easy part: the hard part is knowing what is actually wrong, and that is where most of the money gets wasted.
True rising damp is far less common than the number of chemical DPCs sold would suggest. Condensation, a leaking waste pipe, failed pointing, a raised path bridging the DPC — all of these look like rising damp at skirting level and none of them are fixed by injecting the wall.
The re-plastering is usually the bigger number. A DPC means hacking off contaminated plaster to about a metre and replacing it with a salt-retardant render, at £350–£700 a wall. Budget for it, because a treatment-only quote is not the finished job.
Damp proofing cost (2026)
| Work | Typical 2026 cost | Notes |
|---|---|---|
| Independent damp survey | £150–£400 | From someone not selling treatment |
| Chemical DPC injection | £70–£120/m | Per metre of wall |
| Penetrating damp repair | £45–£80/m | Plus fixing the external cause |
| Basement / cellar tanking | £90–£220/m² | Per square metre |
| Hack off and re-plaster | £350–£700 per wall | Salt-retardant render |
| Re-plaster and redecorate | £600–£1,000 per wall | Finished |
| Fixing the actual cause | varies | Gutter, pointing, leak, ground level |
Figures match our damp proofing cost guide. Get an independent survey before accepting any treatment quote.
Damp proofing calculator FAQs
Statistically, probably not. Rising damp exists but is far rarer than the number of chemical DPCs sold implies. Condensation, a plumbing leak, failed pointing and a path bridging the DPC all look the same at skirting level. An independent survey at £150–£400 is the only way to know.
Because a free survey from a firm that sells damp treatment has one likely outcome. Pay for an independent surveyor with nothing to sell — it is the cheapest money in the job and it is the difference between fixing the problem and paying for the wrong work.
Yes, if a DPC was genuinely needed. The old plaster holds hygroscopic salts drawn up over years and will keep attracting moisture even once the wall is dry. It has to come off to about a metre and be replaced with a salt-retardant render.
No. Rising damp cannot reach an upstairs wall. That is penetrating damp or condensation — look at the gutters, the pointing, the roof and the ventilation instead.
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