The short answer
In 2026, an independent damp survey typically costs £150–£350, and a chemical damp-proof course (DPC) costs around £300–£1,000+ per wall, or roughly £2,000–£5,000 for a whole house including replastering. Mould removal ranges from £200–£1,000 depending on extent. Costs vary widely with the size of the property, the cause and severity, access, and how much plastering is needed. Always get the cause diagnosed independently before paying for treatment.
“Damp-proofing” covers everything from a quick mould clean to injecting a new damp-proof course and replastering, so prices vary enormously. The figures below are typical UK market ranges for 2026 and are a guide only — the actual cost depends on the cause, the size of the affected area and the amount of making-good required. The single most important step is getting an independent diagnosis first, because much “damp-proofing” is sold to fix problems that are really condensation.
Damp-proofing costs at a glance
- Damp survey £150–£350
- Chemical DPC (per wall) £300–£1,000+
- Chemical DPC (whole house) £2,000–£5,000
- Mould removal £200–£1,000
- PIV ventilation unit £400–£1,500 fitted
- Dehumidifier £100–£300
Typical 2026 damp-proofing costs
The table below shows typical UK ranges. They are indicative only: the true price depends on the cause of the damp, the size of the property, ease of access and how much replastering and redecoration is needed afterwards. A survey should always come first, because it determines which (if any) of these treatments you actually need.
| Work | Typical 2026 cost | Notes |
|---|---|---|
| Independent damp survey | £150–£350 | More for a full structural or detailed report |
| Chemical DPC — per wall | £300–£1,000+ | Varies with wall length and thickness |
| Chemical DPC — whole house | £2,000–£5,000 | Usually includes replastering |
| Mould removal / treatment | £200–£1,000 | Depends on the area affected |
| PIV ventilation unit (fitted) | £400–£1,500 | Tackles condensation, not rising damp |
| Dehumidifier | £100–£300 | Management aid, not a cure |
What drives the price
- The cause — condensation is cheap to address (ventilation and heating); penetrating damp depends on the external repair; rising-damp treatment is the most involved.
- Extent and severity — one wall versus a whole house, and how long the damp has been present.
- Replastering — often the biggest single cost in a DPC job, because affected plaster usually has to be hacked off and renewed.
- Access and property type — solid stone walls, awkward access and older buildings push costs up.
- Region — labour rates vary across the UK, with London and the South East typically higher.
How to keep the cost down
Get an independent diagnosis before any treatment — see damp survey and how to get a damp survey. Fix simple causes yourself where you safely can, such as clearing gutters or improving ventilation for condensation. Obtain at least two or three written quotes for any significant work, and check the firm’s credentials, ideally a Property Care Association member; see PCA damp specialist. Be wary of long “guarantees” that are only worth anything if the company is still trading. For the survey cost alone, see damp survey cost.
Why diagnosis changes the cost so much
The single biggest factor in what you pay is which problem you actually have — and that is why the order of spending matters. Condensation, the most common cause, is also the cheapest to resolve: better ventilation and even heating, sometimes a PIV unit at £400–£1,500, rather than thousands on a damp-proof course. Penetrating damp depends entirely on the external repair, which might be a few hours clearing and resealing a gutter or a larger job re-rendering a wall. Rising damp, where genuinely present, is the most involved because of the injection and the replastering that follows. Pay for an independent diagnosis first and you avoid the classic and expensive mistake of buying rising-damp treatment for a problem that was really condensation all along. A £150–£350 survey that redirects you from a £4,000 DPC to a £200 ventilation fix has paid for itself many times over.
Who pays — owner or landlord?
If you own your home, the cost is yours, though buildings insurance may help where damp results from a sudden insured event such as a burst pipe (not general disrepair, which insurers treat as maintenance). If you rent, repairs to tackle damp and mould are generally the landlord’s responsibility, not yours — you should not be paying to damp-proof a rented home, and social landlords have additional duties under Awaab’s Law. See landlord responsibility for damp. The figures on this page are typical UK ranges for 2026, not a quotation for your property.
Get the cause diagnosed before you pay for treatment
An independent damp survey for £150–£350 can save thousands by confirming what is really wrong. These figures are typical UK ranges, not a quote — always get written quotations.
Frequently asked questions
How much does it cost to damp-proof a house?
A chemical damp-proof course for a whole house typically costs around £2,000–£5,000 including replastering, while a single wall is often £300–£1,000+. The exact figure depends on the cause, the size of the property and how much making-good is needed.
Is a free damp survey worth it?
A free survey is usually offered by a firm hoping to sell you treatment, so it carries a built-in incentive to recommend work. An independent paid survey (£150–£350) gives an unbiased diagnosis and can save far more than it costs.
Does buildings insurance cover damp-proofing?
Generally no — insurers treat gradual damp and condensation as maintenance, which is not covered. Insurance may help where damp results from a sudden, insured event such as a burst pipe, but not from long-standing disrepair.
Why is replastering such a big part of the cost?
Where a wall has been wet, the old salt-contaminated plaster usually has to be removed and renewed for the repair to hold. This labour and materials cost is often the largest single item in a damp-proofing job.
Sources & further reading
- Property Care Association (PCA) — choosing a damp specialist and guarantees
- RICS — damp and timber surveying standards
- GOV.UK — Housing Health and Safety Rating System (HHSRS) guidance
- Typical UK contractor market ranges, 2026
This guide is general information, not a site-specific survey, medical advice or legal advice. Damp and mould should be assessed by a qualified surveyor, and health concerns discussed with a GP or the NHS.