What Does Damp Treatment Cost?
Quick Answer
Rising damp injection: £30–£80 per linear metre
DPC replacement £1,500–4,000 per wall. Condensation solutions from £200. Penetrating damp repair varies by cause
Costs by Damp Type (2026 UK)
Rising Damp
- Chemical DPC injection: £30–£80 per linear metre (including re-plastering)
- Typical 3-bed semi (all ground floor walls): £2,000–£5,000
- Single wall treatment: £500–£1,500
Penetrating Damp
- Repointing: £30–£60/m²
- External waterproof render: £40–£80/m²
- Cavity tray installation: £1,000–£3,000
Condensation
- Extractor fans: £150–£400 per room (supply and fit)
- Positive input ventilation (PIV): £400–£800 installed
- Anti-condensation paint: £15–£25 per litre
Signs of Each Damp Type
- Rising damp: Tide marks up to ~1m high, salt deposits, peeling wallpaper at skirting level
- Penetrating damp: Damp patches that worsen in rain, often around windows or on external walls
- Condensation: Black mould in corners, on cold walls, and around windows. Worst in winter
Important Notes
- Get a proper damp survey before committing to treatment — misdiagnosis is common
- True rising damp is rarer than many damp-proofing companies suggest
- Most “rising damp” is actually condensation or penetrating damp
- Chemical DPC injection typically comes with a 20–30 year guarantee
Last updated: April 2026