Brick cleaning in London
Take the soot off, leave the brick alone.
Soot, algae, paint and pollution film off London stock, red and gault brick, by a firm that knows which method your brick can take.
Why London brick gets so dirty
London stock brick was made from brickearth with the city's ash and cinders mixed in, so it fires yellow with black flecks and a pitted face. It is porous on purpose: water drains out fast, which is why these walls shrug off frost. The same open face collects two centuries of coal smoke, diesel film and, on the shaded side, green and black algae. Many fronts have never been cleaned.
The three ways to clean it
Superheated water (often called DOFF cleaning)
Water heated to about 150°C arrives at the brick as a fine, very hot stream with little force behind it and not much water. It lifts soot, biological growth and traffic film and the heat kills spores, so no biocide is usually needed. The wall dries in minutes. This is the first choice for stock brick and most soft masonry because it takes the dirt off, not the face of the brick.
Low-pressure abrasive (TORC, JOS and similar)
A swirling mix of air, a little water and a fine inert powder. Used where soiling is baked on, for example carbon crusts on hard engineering brick or paint on robust surfaces. In skilled hands on the right surface it is excellent; on soft stock brick it can strip the fired skin and open the brick up to weather. A firm should be able to say which brick you have and why they are, or are not, proposing it.
Chemical cleaning and poultices
Gels and poultices held against the wall under film, then rinsed. The usual route for old paint, limewash, oil staining and some graffiti. Needs test patches, neutralising and careful rinsing. Mortar joints and sills take the run-off, so a careful firm protects them.
What a careful firm does differently
- Cleans a discreet trial patch and shows you before quoting the whole front.
- Names the method and why it suits your brick, in writing.
- Inspects joints after cleaning: dirt hides failed mortar, and cleaning often reveals repointing needs.
- Never proposes a domestic pressure washer or sandblasting on a stock-brick front.
What it costs in London
Published guides for 2026 put brick cleaning at roughly £10 to £50 per square metre depending on method and soiling, with a typical house front coming in at around £500 to £700. Scaffold or a tower, listed-building paperwork and parking suspensions all add to that in London. Treat these as a sense-check, not a quote: the trial patch is what sets the real price.
Before you book anyone
If the building is listed, external cleaning can need listed building consent, and in a conservation area the council may still have a view. Read the consent page first. If you are a managing agent, the block page covers consultation and access.
Where these facts come from
- Alan Cox, "Bricks to Build a Capital", Construction History vol. 13 (1997), on the making and character of London stock brick: arct.cam.ac.uk
- Stonehealth product literature on superheated water cleaning (150°C at the nozzle, low water volume, spores killed by heat): NBS Source
- Designing Buildings wiki, "Cleaning brickwork, faience and terracotta", on hot pressurised water and cautions: designingbuildings.co.uk
- Checkatrade cost guide, brick cleaning (2026): £10–50 per m², typical property £500–695. Single published source; verify against quotes.
Checked 16 October 2026. If you spot a mistake, email hello@brickandstonecleaninglondon.co.uk.
Want a trial patch on your brickwork?
Tell us about the building and the problem. One specialist firm receives your enquiry and arranges a look.
Request a visit