How much does roof cleaning and moss removal cost?

Roof cleaning is one of the few roofing jobs where the cheapest quote can genuinely wreck your roof, because the wrong method does more harm than the moss ever did. This guide covers what a proper roof clean and moss removal costs in 2026, which methods are safe, and how long the results last. For prices on other jobs, try our roof cost calculator.

Roof cleaning costs at a glance (2026)

The gutter add-on is worth taking while the access equipment is up: everything scraped off the roof would otherwise end up in the gutters, and a blocked gutter is its own expensive problem. See the guttering cost guide for what that damage looks like in pounds.

Why pressure washing is the wrong answer

Concrete and clay tiles have a weathered surface layer that does real work: it sheds water and protects the tile body beneath. A pressure washer blasts that surface off along with the moss, leaving the tile porous and ageing it years in an afternoon. The jet also drives water up under the tiles and into the roof space, and can strip pointing from ridges and verges while it is at it.

Does moss actually damage roofs?

Yes, and not just cosmetically. Moss works like a sponge, holding moisture against the tile surface for weeks after rain. In winter that trapped water freezes and expands, spalling the face off tiles a little more each cycle. Clumps also break off and wash into the gutters, where they cause the blockages behind so many mystery damp patches, and thick growth at tile edges can lift the covering enough to let wind-driven rain through. If your roof is turning green, our guide to moss on the roof explains what is happening up there and when to act.

How long do the results last?

A manual scrape with biocide treatment typically keeps regrowth down for 2 to 4 years. The biocide is the part doing the long-term work: it kills the spores the scraper cannot reach, so the roof stays clean well after the visible moss has gone. Aspect matters more than anything else, though. North-facing roof slopes and roofs shaded by trees stay damp longer and regrow fastest, so they sit at the shorter end of that range, while a sunny, open south-facing roof can stay clean for years beyond it. A scrape without biocide greens over noticeably sooner, which is why the treated option is usually worth the extra £100 or so.

Moss removal cost by roof size

Roof cleaning is priced by the square metre and by access, so the house type tells you most of what you need to know.

Scaffolding is rarely needed. Most cleans are done from a roof ladder or a tower, which is why a clean costs a fraction of a repair on the same roof. Steeply pitched, three-storey or slate roofs sit at the top of each range because access slows everything down.

Scrape, soft wash or biocide only

Three methods, three prices, and they do different jobs.

• Manual scrape, £400 to £800 on a semi. Physical removal with hand tools. Instant result, no tile damage when done properly, and the only method that clears thick growth.
• Soft wash, £500 to £1,000. Low pressure with a cleaning solution. Gentler on old clay and slate, slower, and better on staining than on deep moss.
• Biocide treatment alone, £250 to £500. Sprayed on and left. The moss dies over three to six months and weathers off. Cheapest, no instant transformation, and the right call if the growth is thin.

A scrape followed by a biocide treatment is the combination reputable firms recommend, because scraping alone leaves spores behind and the moss is back inside three years.

How often does a roof need cleaning?

Every five to ten years on a north-facing or tree-shaded roof, and often never on a south-facing slate roof in full sun. Anyone selling an annual clean is selling a subscription, not a need. Have the gutters cleared yearly instead at £80 to £200, which is what actually prevents damage.