Typical cost in 2025
Most homeowners pay around £1,200 for a chemical DPC injection on a single wall with replastering
What affects the price?
Type of damp
Rising damp (failed DPC) requires injection treatment. Penetrating damp (rain ingress) requires external fixes (pointing, cladding, guttering). Condensation is managed with ventilation and insulation — not chemical treatments.
Affected area
A single rising damp wall (5–10m run) costs £500–£1,500 for injection and basic re-plastering. Whole ground-floor treatment covering multiple walls can run £2,000–£5,000+.
Replastering
After DPC injection, salt-contaminated plaster must be hacked off and replaced with renovation plaster to at least 1m high. Replastering adds £300–£800 per room depending on area.
Tanking
For basements or below-ground spaces, tanking (applying a waterproof membrane) costs £50–£100/m². A typical basement (30m²) can cost £1,500–£3,000 for tanking alone.
Survey and guarantee
A reputable specialist will provide a full damp survey and a 10–20 year guarantee on treatment. Budget £100–£200 for a paid survey that goes toward work if you proceed.
Typical cost breakdown
Estimates are based on UK average rates in 2025. Prices in London and the South East are typically 20–30% higher.
Frequently asked questions
What are the signs of rising damp?
Tide marks on lower walls, peeling paint or wallpaper below 1m height, white salt deposits (efflorescence) on walls, and a musty smell. Rising damp rarely exceeds 1–1.5m above floor level.
Is rising damp as common as specialists claim?
This is contested — some experts argue true rising damp is rare and often misdiagnosed. Many cases are actually condensation or penetrating damp. Always get a second opinion before authorising expensive treatment.
Does home insurance cover damp?
Generally no — damp is considered gradual deterioration rather than sudden damage. Exceptions include damp caused by a burst pipe or storm damage, which may be covered.
How long does a DPC treatment last?
A chemical DPC injection typically comes with a 20–30 year guarantee. The treatment itself lasts the lifetime of the building if installed correctly and the cause of moisture is also addressed.
Can I fix damp myself?
Condensation and some forms of penetrating damp can be addressed with DIY fixes (improving ventilation, fixing gutters, repointing). Rising damp treatment should be done by a specialist with proper equipment and a written guarantee.