Should You Scrape Moss Off Your Roof Yourself?

The moss is the easy part. Getting to it safely, without breaking the roof, is the hard part.

The short answer

You can, but for most houses you shouldn’t. Scraping moss means working at height on a wet, sloping surface that was never built to be walked on. The risk isn’t the moss. It’s the ladder, the roof pitch and the tiles under your feet.

If the roof is a single-storey garage, shed or low extension you can reach safely from a secured ladder without stepping onto it, careful DIY is realistic. For a two-storey house roof, it’s a job for someone with the right access equipment and insurance.

What goes wrong with DIY moss scraping

• Falls. The Health and Safety Executive lists falls from height as one of the biggest causes of fatal and serious injuries at work in Great Britain, and that’s among people trained and equipped for it. See the HSE’s work at height guidance. A homeowner on a wet roof with a garden hoe has none of those protections.
• Cracked and slipped tiles. Roof tiles are designed to shed water, not carry a person. Standing on the wrong part of a tile cracks it, and older clay tiles and natural slate break easily. One cracked tile can let water in for months before you notice.
• Surface damage. Metal scrapers and wire brushes scratch the surface of concrete tiles. A rougher surface holds more water and gives new moss an easier place to root.
• Pressure washers make it worse. Jet washing from a ladder strips the tile surface, forces water up under the laps and pushes you backwards off the ladder. See soft wash vs jet wash.
• Blocked gutters and downpipes. Scraped moss has to go somewhere. If it isn’t caught and cleared, it ends up in the gutters and causes overflow. See gutter cleaning.
• It grows back. Scraping removes the bulk but leaves spores and root fragments in the tile surface. Without a biocide treatment afterwards, regrowth usually starts again within a season or two.
• Asbestos. Some fibre-cement slates and garage roof sheets fitted before 2000 contain asbestos. Never scrape, brush or pressure wash them. See slate roof cleaning.

If you’re going to do it anyway

For a low, easily reached roof only:

1. Work from a ladder that is tied or footed, on firm level ground. Don’t step onto the roof.
2. Pick a dry, still day. Wet moss and wet tiles are slippery.
3. Use a plastic or wooden scraper or a stiff brush on a pole, never metal.
4. Work downwards, from ridge towards gutter. Scraping upwards lifts tiles and breaks the laps.
5. Put a sheet on the ground and a guard over the gutter, then clear the gutter afterwards.
6. Follow with a moss treatment used exactly as the label says, and keep it away from ponds, drains and pets. See pet-safe biocide and biocide vs bleach.
7. Never work alone.

If any of that isn’t possible on your roof, that’s the sign to get a quote instead.

How a specialist does it differently

Professional moss removal is normally done from the ground or from proper access equipment, using long-reach poles so nobody stands on the tiles. The moss is scraped off by hand, the debris is collected, the gutters are cleared, and the roof is then soft washed with a biocide that carries on killing what’s left in the tile surface. More on the method: moss removal and soft washing.

The right approach also depends on what your roof is made of: concrete tile, clay tile or slate.

Does moss need to come off at all?

A thin scatter of moss is mostly cosmetic. Thick cushions are different: they hold water against the tile, add weight, block gutters when they fall, and can lift tile edges as they grow into the laps. If you can see it clearly from the road, it’s worth dealing with. See 5 signs your roof needs a clean.

What to do next

Hampshire Roof Care is a matching service: tell us about the roof and our vetted local specialist partner quotes it directly. WhatsApp 023 8129 0232 or send an enquiry with a photo or two. Local pages: Southampton · Eastleigh · Winchester · Romsey · Fareham · Alton · Emsworth · Waterlooville · Havant.

Quick answers

Can I scrape moss off my roof myself?

On a low roof you can reach safely from a secured ladder, yes, with a plastic scraper and working downwards. On a two-storey house roof it is not worth the risk of a fall or cracked tiles, so use a specialist with proper access equipment.

Does scraping moss off a roof damage the tiles?

It can. Metal scrapers and wire brushes scratch concrete tiles, walking on tiles cracks them, and scraping upwards lifts them. Scraping with a plastic or wooden tool from a pole, working downwards, avoids most of the damage.

Will moss grow back after scraping?

Yes, unless the roof is treated afterwards. Scraping leaves spores and root fragments in the tile surface, so a biocide treatment after scraping is what slows regrowth.