What does a damp proofing cost in London?
In London: £1,900 to £5,600 at mid-range, including 20% VAT, against £1,500 to £4,500 nationally. Budget starts around £1,300, premium runs to £9,000. Set your finish level and region below, no email required.
Damp proofing, mid-range, London
£1,900 to £5,600
Including 20% VAT. An indication, not a quote: prices vary per trade and property.
Take it further
Prices include 20% VAT. New builds and some energy-saving works can qualify for 0% or reduced VAT; ask your installer.
Got quotes in already? Check if they are fair. Want to know when the money leaves? See the phase-by-phase plan.
What drives the price
- The diagnosis: rising damp, penetrating damp and condensation need different fixes.
- The treatment: an injected course is the middle of the range; tanking is the top.
- Making good: replastering after treatment is often half the bill.
- The cause: gutters, ground levels and ventilation fix more damp than chemicals do.
All figures come from the same validated 2026 price data as the calculator above (sources: Checkatrade, MyJobQuote and comparable national 2026 cost guides, checked August 2026; see how we price), so this page and your estimate can never disagree. Outside London? See the national guide, or compare every region in the regional overview. How to pay for it (remortgage, loan or savings) is its own guide: paying for a renovation. Planning an extension or loft? Check permitted development first.
Frequently asked questions
Do I really need damp proofing, or better ventilation?
Get an independent survey first: a large share of "rising damp" turns out to be condensation or a leak, solved by ventilation, gutters or pointing at a fraction of the price. Be wary of free surveys from firms selling the treatment.
Do these prices include VAT?
Yes, all ranges include 20% VAT. New builds and some energy-saving works can qualify for 0% or reduced VAT; ask your installer whether your project applies.
Why is London so much more expensive?
Labour is the driver: London trades charge roughly 25% above the national average, and parking, access and waste logistics add friction. Nationally this project runs £1,500 to £4,500; the calculator switches region in one click.
How accurate is this range?
It is a guide range from national 2026 cost guides, adjusted for finish level and region. Real quotes vary per trade, property and specification; treat it as a starting point, budget 10 to 15 percent contingency, and always get at least three itemised quotes.