Roof moss removal in Prescot and across Merseyside
Merseyside weather is kind to moss and hard on roofs. Damp air off the Mersey, mild winters and plenty of rain mean the concrete tiled roofs on semis in Prescot, Whiston and Rainhill green over faster than most parts of the country. Once moss takes hold on the north-facing slope it spreads year on year, and by the time clumps start landing on the drive the roof is holding far more water than it should.
Blastaway Pressure Washing Services cleans roofs across Prescot, Knowsley, St Helens, east and south Liverpool and Widnes. The moss comes off by hand, the roof gets a soft wash treatment to kill what’s left, and the tiles stay in one piece.
Roofs we clean
- Concrete tiles, the standard roof on interwar semis and newer estates across Knowsley and St Helens
- Clay tiles on older properties
- Slate roofs on Victorian terraces, cleaned gently because slate cracks if you get heavy with it
- Bungalows, semis, terraced houses and larger detached homes
Why we never jet wash a roof
A pressure washer has its place, and that place is on the ground. Pointing a jet wash lance at a tiled roof causes three kinds of damage. It cracks and dislodges tiles, especially older slate and brittle clay. It strips the sandy surface layer off concrete tiles, which leaves them more porous, so the moss grows back thicker within a couple of years. And it forces water up under the tiles into the felt and the loft, which is how a cosmetic problem turns into a damp problem.
Roof cleaning done properly is mostly hand work and low pressure. If a firm turns up planning to blast your tiles the way they’d blast a driveway, send them home.
How we clean a roof
- Assessment first. Tile type, age, pitch and condition all decide the method. A slate terrace in St Helens gets treated very differently to a concrete tiled semi in Huyton.
- Moss off by hand. Scrapers and stiff brushes take the thick growth off tile by tile, working from proper access equipment rather than clambering about on the roof itself.
- Soft wash treatment. A biocide applied at low pressure kills the algae, lichen and moss spores the scraper can’t reach, and it carries on working long after we’ve packed up.
- Steam where it suits. Some roofs respond better to high temperature at low pressure than to chemicals, so we carry both options and pick whichever suits the surface.
- Tidy up. The scraped moss gets bagged, the gutters are cleared of the debris that’s dropped in, and the paths and drive are rinsed down before we leave.
What moss actually does to a roof
Moss holds water like a sponge, and in a Merseyside winter that water freezes. Repeated freezing and thawing opens hairline cracks in tiles and works the pointing loose on ridges and verges. Clumps wash into the gutters, the gutters block, and rainwater runs down the wall instead, which is where those green and black streaks on render and pebbledash come from. Left long enough, a mossy roof stops being a cleaning job and starts being a roofing bill.
Shaded roofs suffer most. On the leafier roads of south Liverpool, and anywhere with big trees close to the house, tiles stay damp for days after rain and moss thrives. Those are the roofs worth treating on a regular cycle rather than waiting until the growth is thick enough to see from the end of the street.
Get a free fixed quote
Every roof is priced on the job itself. Tell us where you are and what is growing up there and we’ll sort you out. Before any work starts we agree a fixed price in writing. It’s a free quote, and the price doesn’t move once it’s agreed.
