Costs
What sits inside a damp treatment cost.
The cheap line on a damp quote is often the injection. The wall still has to be opened, replastered and left to dry, and none of that is the same visit as finding out why the wall is wet.
Checked 13 October 2026. Pounds, for homes in England. The Malta directory uses euro and is a different list.
These bands are a reference before you phone. Local Trades UK does not diagnose the wall and does not price the treatment.
Name the damp before you price the treatment
A stain that tracks rain, high on a wall or across a ceiling, is a different problem from a tide mark low on a ground-floor wall, and both are different from black mould in a cold corner that gets worse in winter. The first of those is often a leak. Read a damp patch that appears after rain before you accept a price for a new damp course. A chemical injection does not repair a gutter, a flashing or a roof.
What the published bands leave out
The Checkatrade damp proofing cost guide, table marked last updated June 2026, says the prices on that page exclude removal of plasterboard or render, making good afterwards, decoration and finishes, drying out, and the survey. An average of about £5,000 for a typical property on that page is not the price of a short injection, and the injection band is not a finished room.
| Line | Range | Average on that table |
|---|---|---|
| Injection, per metre | £60–£200 | £100 |
| Injection, or chemical treatment, as a job | £1,000–£3,000 | £2,000 |
| External walls, injection | £1,000–£3,000 | £2,000 |
| Physical damp course, retrofitted | £2,500–£7,500 | £5,000 |
| Cellar or basement tanking | £100–£200 per m² | £125 per m² |
| Damp survey | £100–£600 | £300 |
Ask which of those exclusions are still outside the quote you have been given. A per-metre rate that stops at the holes in the mortar will look small beside a quote that includes salt-resistant plaster and decoration. They are not the same job.
The guide does not publish separate totals for London, Manchester, Birmingham, Leeds or Bristol. This page does not add one.
Who you phone
If the pattern is a leak from above, start with the roofing list or the roof price guide. If you already have a survey that points at damp treatment, use the damp proofing list. The local list large enough to open as a set is London. You phone the business yourself.
Source
- Checkatrade, damp proofing cost guide. Table last updated June 2026. Page checked 13 October 2026. The guide lists the exclusions used in the table above.
Questions on this figure
Does a per-metre damp price include new plaster?
The Checkatrade damp proofing cost guide, table last updated June 2026, says its prices exclude removal and making good of plasterboard or render, decoration, drying out, and the survey. An injection band of £60 to £200 a metre, average £100, is the injection line under those exclusions.
Is every wet wall a damp-course job?
No. A patch that appears after rain, high on a wall or on a ceiling, is often a leak from a roof, gutter, flashing or window. That pattern is described on the maintenance note about a damp patch after rain. A chemical damp course does not repair a leak.