Cost of Damp Treatment in the UK (2025)
Damp treatment for a single wall costs £300–£1,500. A full rising damp chemical injection for a 3-bed house costs £1,500–£4,000.
Types of damp and treatments
Rising damp occurs when moisture travels up through walls via capillary action — treated with a chemical damp proof course (DPC) injected into the wall at low level, followed by replastering with salt-resistant render. Penetrating damp enters through defective external features (cracked render, leaking gutters, failed pointing) — the cure is fixing the source, not applying chemicals. Condensation damp is caused by poor ventilation — the fix is improved ventilation (extractor fans, trickle vents) and better heating.
Getting a survey first
Damp surveys cost £150–£300 and are essential before committing to treatment. Be cautious of free surveys offered by damp treatment companies — they are sales tools and may diagnose every issue as rising damp requiring their services. An independent surveyor gives unbiased advice.
Cost Breakdown
All prices are indicative UK averages for 2025. Actual costs vary by location, specification, and contractor. London and South East rates are typically 20–35% higher.
| Item | Low | High |
|---|---|---|
| Damp survey (independent) | £150 | £300 |
| Chemical DPC injection (per m) | £30 | £80 |
| Single wall rising damp treatment | £300 | £800 |
| Full ground floor rising damp | £1,500 | £4,000 |
| Penetrating damp repair | £200 | £1,500 |
| Condensation treatment (ventilation) | £200 | £600 |
What Affects the Cost?
- ✓Type of damp — rising, penetrating, or condensation
- ✓Length and height of affected walls
- ✓Whether plastering and decoration is included
- ✓Extent of damage — timber floors or joists affected by damp cost more to treat
- ✓Whether a tanking system is needed (basements)
- ✓Location — London and South East rates are higher
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Post a Job — It's FreeFrequently Asked Questions
Does rising damp treatment come with a guarantee?
Most professional damp proofing companies offer a 20–30 year guarantee on chemical DPC work. Ensure the guarantee is backed by an insurance policy (not just the company itself) in case they cease trading.
Can I treat damp myself?
You can buy DPC cream and inject it yourself for minimal cost. However, if the plastering is not replaced with salt-resistant (renovating) plaster, the old plaster will continue to show salt staining. Professional treatment includes the re-render as well as the chemical DPC.
How long does damp treatment take?
A single-room treatment takes 1–3 days including plaster drying time. A full property treatment takes 1–2 weeks.