Why moss is a problem
Somerset's mild, damp climate is ideal for moss, especially on north-facing slopes and roofs shaded by trees. Moss acts like a sponge. It keeps tiles wet for longer, which speeds up frost damage on porous tiles. Thick clumps can grow up under the tile above and lift it, letting rain blow in. When moss dries and breaks off, it washes into the gutters and blocks outlets and downpipes, so water spills over and soaks fascias and walls.
How roofs are cleaned
- Moss is scraped off by hand, working down the roof so tiles aren't lifted.
- Remaining growth is brushed away from tile surfaces and laps.
- A biocide treatment can be applied to slow regrowth on the cleaned surface.
- Gutters and downpipes are cleared of the debris knocked down.
High-pressure washing is quicker but can scour tile surfaces, force water under the laps and wash out ridge mortar, so a gentler approach is usually better for the roof.
Spotting repairs while we're up there
Cleaning a roof means seeing every tile up close. Cracked tiles, slipped slates, loose ridges and worn flashing hidden under moss become obvious. We'll point them out so you can decide whether to deal with them; repairs are covered on our roof repair page. If you'd like a full condition check at the same time, see our roof inspection page.
Roof coatings
Roof coatings are paint-like products applied to clean tiles to change their colour or add a protective layer. They can freshen the look of a tired concrete tile roof, but they don't fix cracked tiles, failed fixings or worn underlay, and some surveyors question coatings on certain roofs. We'll give you an honest view of whether a coating is worth it on yours. Similar questions apply to exterior wall coatings, which are covered under our exterior painting service.
Which roofs suffer most
Concrete tiles have a rough surface that moss grips easily, so post-war estates often show the heaviest growth. Clay tiles and slate grow less, but lichen can still take hold. North-facing slopes, roofs near hedges or woodland and houses in valleys that stay damp all collect more. Flat roofs with standing water can grow moss and algae too, which hides splits in the covering. Knowing this helps you judge how often a clean is likely to be needed and whether a treatment to slow regrowth is worth adding.
Keeping gutters clear
After cleaning, gutters often hold a season's worth of moss. Clearing them is part of the job. If they're cracked, sagging or the fascias behind them are rotten, our guttering, fascias and soffits service can replace them.
Book a roof clean
We work across Somerset and Devon within about 50 miles of Taunton, on homes and commercial buildings. Call 07399 680142 or send your details for a free written quote.