Why moss on a roof matters
A little moss is not an emergency, but heavy growth causes real problems. It acts like a sponge, keeping the tiles wet for longer. In winter that moisture can freeze and flake the surface of concrete and clay tiles. Clumps lift the tile edges, letting wind-driven rain underneath, and when moss falls it ends up in the gutters and downpipes.
North-facing slopes and roofs under trees are the worst affected, which is why so many Essex homes have one clean side and one green side.
How roof cleaning is done properly
A careful roof clean generally follows these steps:
- Inspect the roof first, noting any cracked, slipped or loose tiles so they are not made worse
- Remove the bulk of the moss by hand with scrapers and soft brushes, working down the slope
- Apply a biocide treatment to kill remaining spores and slow regrowth
- Clear the moss and debris out of the gutters and check the downpipes run freely
Why aggressive pressure washing can damage tiles
High-pressure jet washing looks quick and dramatic, but on many roofs it does more harm than good. It can strip the surface coating from concrete tiles, leaving them more porous and quicker to grow moss again. It can force water up under the laps and into the loft, wash out mortar from ridges and verges, and crack older or brittle tiles.
Some roofs, especially older or fragile ones, should not be walked on or washed at all. Where tiles are already failing, cleaning is not the answer, and a repair or replacement is the honest recommendation.
Cleaning versus repairing
Moss sometimes hides other problems. Once it is off, slipped tiles, cracked ridges or worn valleys become visible. We would rather tell you about those than clean over them. Our roof repairs service covers the fixes, and a roof inspection is the right starting point if you simply want to know what condition the roof is in.
Gutters after a roof clean
However carefully a roof is cleaned, debris ends up in the gutters. Clearing them out afterwards is part of doing the job properly. If the gutters have also been leaking or sagging, see our gutter repairs page.
Roof cleaning in Essex
We are based in Witham and cover Essex and the Essex side of London's outskirts. Call Lee on 07947 758052 or get in touch online to talk about your roof. He will look at the roof, explain what cleaning would involve and give you a written price.
Keeping a roof clean for longer
After a clean, a few simple steps help keep moss at bay. Trim back overhanging branches so the roof gets more light and dries faster. Keep gutters clear so water drains away rather than sitting at the eaves. Keep an eye on north-facing slopes, where growth returns first. Some owners have a biocide treatment reapplied from time to time rather than waiting for heavy growth to build up again.