How much does damp proofing cost in 2026? (UK price guide)
Updated June 2026
Damp proofing in the UK typically costs £300 to £5,000+, depending on the cause and how much wall is affected. A single wall of rising damp with replastering is usually £600–£1,500; full basement waterproofing runs into several thousand. The honest answer is that you can’t price damp work properly without diagnosing the cause first — and that’s exactly where most people overpay.
Here’s how the costs break down, and what to watch for.
What you’re actually paying for
Damp proofing isn’t one job. The price depends on which problem you have:
- Rising damp treatment — a new damp-proof course (usually injected cream) plus removing and replacing salt-damaged plaster. Most of the cost is the replastering and making good, not the injection itself.
- Penetrating damp — fixing the source (failed pointing, a cracked render, a leaking gutter) then treating the inside. Cost depends entirely on what’s letting water in.
- Condensation and mould — often the cheapest to resolve, because the fix is ventilation and heating behaviour, not building work.
- Basement or cellar waterproofing — the most expensive, because it involves tanking or a cavity drainage system across large areas.
Typical UK price ranges
| Job | Typical cost |
|---|---|
| Damp survey | £150–£300 (often refunded against work) |
| Rising damp treatment, single wall | £600–£1,500 |
| Rising damp, whole ground floor | £2,000–£4,000 |
| Penetrating damp repair | £500–£2,500 |
| Condensation / mould treatment | £300–£1,000 |
| Basement / cellar waterproofing | £4,000–£15,000+ |
These are guide figures for 2026. Your actual quote depends on access, the state of the plaster, and how far the problem has spread.
What pushes the price up
A few things make a real difference to the final number:
- The amount of replastering. Removing and re-applying salt-resistant plaster is labour-heavy and often the biggest line on the invoice.
- How far the damp has travelled. Caught early, it’s one wall. Left for a year, it’s the whole room and the skirting and floor.
- Access and disruption. Fitted kitchens, built-in units and awkward corners all add time.
- The wrong diagnosis. This is the expensive one. Paying for a rising-damp treatment when the real problem was condensation means you’ve spent money and still have the damp.
How to avoid overpaying
Get the diagnosis right before anyone quotes for work. A proper survey tells you what’s genuinely wrong — and sometimes that the “rising damp” a previous survey flagged is actually condensation that costs a fraction to fix. Look for a specialist who works to Property Care Association standards, gives you a written diagnosis, and puts the survey fee towards the work.
If you’re buying a house and damp showed up on the survey, don’t panic-price it from the worst case. A specialist inspection often finds the real cost is far lower than the homebuyer report implied.
Frequently asked questions
Is a cheap damp proofing quote a red flag?
Not always, but be cautious of anyone quoting for treatment without surveying first. A low price for the wrong fix is the most expensive option of all.
Does the survey fee get refunded?
With most reputable firms, yes — the survey fee comes off the cost of any work you go ahead with, so if you use them the survey is effectively free.
How long does damp proofing last?
Properly diagnosed and treated work is usually backed by a guarantee of up to 30 years. The key word is “properly” — the guarantee only means something if the original diagnosis was right.
Will I need to redecorate afterwards?
Usually. New plaster needs to dry out fully (often several weeks) before painting. A good specialist will tell you the timeline up front so you can plan.