Roof cleaning and moss removal Dublin

The short answer

Moss on a roof is not only ugly. It holds water against the tiles, lifts them in frost and blocks the gutters every time it dries out and rolls off.

We remove moss from roofs across Dublin by hand, scraping and brushing each course, then clear the gutters and downpipes of what came down and apply a biocide treatment to slow regrowth.

We do not pressure wash roofs. It strips the surface off concrete tiles, drives water under slates and fills the loft with spray. A hand clean takes longer and does no harm.

Why Dublin roofs grow moss

It is the climate. Mild, damp and rarely dry for long, which is exactly what moss wants. Add a north-facing slope that never sees direct sun, a tree overhanging one end of the roof, or the rough surface of a concrete tile that gives spores something to grip, and a roof can go from clean to green in a few years. The estates of concrete-tiled houses built across Dublin from the sixties onwards are the worst for it, but slate roofs get it too, especially along the lower courses where water runs slowest.

Left alone, moss does real damage. It soaks up rain and holds it against the tile, which in a frost expands and cracks the tile or pushes it up off its neighbour. Clumps break off in dry weather and go straight into the gutter, and a gutter full of moss overflows onto the fascia and the wall below. On slate roofs the moss wedges into the gaps and lifts the slates enough to let wind-driven rain underneath.

What the roof clean includes

The whole job is done from the roof, on a roof ladder or from a scaffold tower depending on the pitch and height, never from the ground with a jet.

• Moss scraped off each course by hand with a tile scraper, working from the ridge down
• Roof brushed off with a stiff brush so the loose growth and grit come away
• Ridge tiles, hips and valleys cleared and checked while we are up there
• All the debris that came down cleared from the gutters and the downpipes flushed
• A biocide treatment sprayed over the cleaned roof to kill what is left in the joints and slow regrowth
• Any cracked, slipped or lifted slates and tiles we uncover noted with a photo and priced separately
• Ground, paths and beds cleared of what fell, and the moss taken away
• Before and after photos from the same spot sent the same day

Why we do not pressure wash

A pressure washer will take moss off a roof in an hour, and it will take the top surface of the tile with it. Concrete tiles have a thin coloured face that protects the porous concrete underneath; strip that and the tile soaks up water, goes darker, and grows moss faster than it did before. On slate the jet drives water up under the slates and into the loft, and on any roof it washes the moss and grit straight into the gutters and down the drains.

Hand scraping is slower and it is the right way. It takes the moss off without harming the surface, and because we are on the roof we see every slate and tile as we go, which is how a roof clean turns up the loose one that was going to leak next winter.

After the clean

The biocide treatment keeps working after we leave. Moss that is left in the joints dies off over the following weeks and weathers away with the rain, so a roof looks better a month after the clean than it does on the day. How long it stays clear depends on the roof: a south-facing slate roof with no trees might stay clean for years, a north-facing concrete tile roof under a sycamore will need looking at again sooner. We will tell you honestly which yours is.

If the moss is a recurring problem on one slope, copper or zinc strips along the ridge are worth talking about. Rainwater picks up traces of the metal as it runs down and discourages new growth. It is not a cure, but it helps.

How it goes

1. Ring or send a photo. A photo of the roof from the road or the garden shows us how heavy the growth is and what the roof is made of. That is usually enough for a price.
2. Written price within 48 hours. One price for the clean, the gutter clear and the treatment. Access equipment is in the quote so nothing appears on the day.
3. The clean. A morning for a bungalow, a day for most two-storey houses. We work from the ridge down and keep the gutters clear as we go.
4. Treatment and photos. Biocide applied to the cleaned roof, then before and after photos the same day, with a note of any slates or tiles that need attention.

What we do not do

We clean pitched slate and tile roofs on houses. We do not pressure wash, we do not clean flat roofs or asbestos-cement sheeting, and we do not paint or coat roofs; the coatings sold as a roof cure trap moisture and fail. If the moss is hiding a roof that is at the end of its life we will show you that in the photos and say so.

Common questions

How much does roof moss removal cost in Dublin?

It depends on the size and pitch of the roof, how heavy the moss is and what access is needed. A bungalow from a roof ladder is a smaller job than a two-storey house that needs a tower. We give one written price that includes the gutter clear and the treatment.

Will removing the moss damage my tiles?

Not by hand. We scrape and brush, we do not jet wash, and we step only on the strong parts of the tile. Occasionally the moss has already cracked or lifted a tile, and we will photograph that and price the replacement separately rather than leave it.

Can I clean the moss off my own roof?

You can, but it is a job done from the roof, on a proper roof ladder, and it is the getting up and down that hurts people. If you are going to do it, do it in dry weather, work from the ridge down and keep off the gutters. Otherwise ring us.

How long before the moss comes back?

It varies with the roof. A treated roof that faces south with no trees near it can stay clear for years. A shaded north slope under trees will need attention sooner. We tell you which yours is on the day, and copper ridge strips are an option where it keeps returning.

Get a free quote

Call 085 781 4603 or request a quote. Free site visit, written quote within 48 hours.