Moss removal and gentle roof cleaning to protect the covering
Moss Removal, Roof Cleaning and Soft Washing
Moss removal and roof cleaning is the process of clearing moss, algae and lichen from a roof covering — usually by careful scraping and a low-pressure soft wash with an appropriate biocide — to stop growth trapping moisture against tiles or slates and shortening their working life.
Definition
What Roof Cleaning covers
Moss and algae growth on a roof holds moisture against the covering, which accelerates frost damage, can lift tiles, and blocks gutters as it washes down. Cleaning is carried out by scraping away growth and applying a soft wash — low-pressure water with a biocide treatment — rather than high-pressure jet washing, which can damage tiles, dislodge fixings and force water beneath the covering. It's a maintenance measure rather than a repair, and doesn't fix underlying defects such as failed pointing or flashing.
Suitable for
- Roofs with visible moss, algae or lichen growth, particularly on north-facing or overhung slopes
- Routine roof maintenance to extend the working life of tiles or slates
- Preparing a roof ahead of a coating application
- Properties with gutters regularly blocked by moss washing down
Not suitable for
- Roofs with underlying structural, tile or flashing defects — cleaning doesn't fix these, and we'll flag any repairs found during the clean
- Fragile or very aged coverings where the removal process itself risks dislodging tiles — assessed before starting
Process
How the work is carried out
- 01
Survey
Assessing the extent of growth and the roof covering's condition before agreeing a cleaning approach.
- 02
Scrape and clear
Removing moss and heavy growth by hand, clearing debris from the roof and gutters.
- 03
Soft wash
Applying a low-pressure wash with an appropriate biocide treatment to kill remaining growth and slow regrowth.
- 04
Completion
Clearing all debris from the roof and gutters, and checking for any defects uncovered during the clean.
Typical timescale
A standard semi-detached roof is typically cleaned within a day; larger or heavily overgrown roofs take longer.
Cost guidance
Moss removal and roof cleaning typically costs £5–£15 per m² in our area, often quoted as a fixed price for the whole roof based on size, with the extent of growth and access requirements pushing the price toward the top of that range. We provide an itemised quotation after a site visit rather than a fixed headline price.
Limitations and exclusions
- Cleaning is a maintenance measure and doesn't repair underlying defects such as failed pointing, flashing or damaged tiles — these are quoted separately if found
- High-pressure jet washing is not used on tiled or slated roofs, as it risks damaging the covering and forcing water beneath it
- Regrowth over time is normal; a biocide treatment slows but doesn't permanently prevent moss returning
Areas we cover
Roof Cleaning across Sussex, Surrey, Kent and South London
Local property styles, planning authorities and neighbourhood coverage for roof cleaning in each town we work in.
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FAQs
Roof Cleaning FAQs
Is jet washing safe for my roof?
No — high-pressure jet washing can dislodge tiles, damage the surface and force water beneath the covering. We use a low-pressure soft wash with an appropriate biocide instead, which cleans effectively without that risk.
Will moss removal stop moss coming back?
The biocide treatment slows regrowth significantly, but moss and algae are a natural process on most roofs, especially shaded or north-facing slopes, so some regrowth over time is normal. Periodic cleaning as maintenance keeps it under control.
Should I clean my roof before or after having it coated?
Before — a roof needs to be free of moss, algae and dirt before a coating is applied, otherwise the coating won't adhere properly or will trap growth beneath it. We typically clean as the first stage of a coating job.
Discuss your roof cleaning project
Tell us about the property and what you have in mind, and we'll arrange a site visit.
Last reviewed 2026-07-28.