Why are birds pulling moss off my roof?

You're not the only one

It's one of those things people assume only happens to them. On Mumsnet, one homeowner wrote: "Birds clean the moss from mine, but then it's all over the path." Another described moss "constantly dropping on the patio" from a slope that never gets any sun. On the MoneySavingExpert forum, a homeowner with crows and pigeons on the roof thought they were there "to peck at the moss and leaves", and noticed the result: "it tends to roll down the roof and lands in the gutters blocking them up."

Why birds do it

There are two reasons, and both are natural.

Food. Moss holds damp, and damp holds life. A Cumbria Wildlife Trust column notes that moss hides soil mites "which birds will eat", and suggests magpies tearing at roof moss are likely after the insects living in or under it. Jackdaws, which the RSPB says are "well known for nesting in chimneys", eat insects, seeds and fruit.

Nests. Moss is soft, warm and easy to weave. The same column says that "many garden birds such as chaffinches, goldfinches, blackbirds and robins actually build the nest with woven moss", and that dunnocks line their nests with it. Gardeners' World notes that wrens use a larger amount of moss than most.

Which birds, and why

Where the moss ends up

Moss pulled off a roof doesn't disappear. It goes three places:

• Into the gutters. Clumps roll down the slope and settle in the gutter, often right above the outlet. One Mumsnet user found their gutters "full of moss and dirt that had come off the roof".
• Down the downpipes. A clump that reaches the outlet can wedge in the bend at the top of the pipe, and then even a clear gutter overflows.
• Onto paths, patios, conservatory roofs and lower flat roofs, where it holds water and makes surfaces slippery.

Is it damaging the roof?

The MoneySavingExpert homeowner worried that "when they pull that out surely that may damage or dislodge the tile." Nobody in the thread could say. The more useful question is what the moss itself is doing. Marley, one of the UK's biggest tile makers, says light moss isn't normally harmful, but a heavy build-up "will inhibit the flow of water off the tiles". If birds are visiting often, it's usually because there's plenty of moss to visit.

If you can see slipped or cracked tiles as well, have those looked at. They need repairing whatever caused them.

Can you stop them?

Not really, and you wouldn't want to. As another MoneySavingExpert user put it, short of netting the whole roof "there is nothing you can do to stop birds landing on it." What you can do is take away the reason they're there, by having the heavy moss removed.

Timing matters, because nests are protected by law. The RSPB says "March to September marks the main nesting season", and that it's illegal to "deliberately take, damage or destroy the nest of any wild bird while it is in use or being built". NFRC, the roofers' trade body, reminds roofers that if they know birds are nesting, they mustn't start work. So book moss removal for late autumn or winter, once the nests are empty.

What we'd do

If birds are scattering moss across your patio and into your gutters, we'll remove the moss from the roof by hand in winter, outside nesting season, and clear the gutters and downpipes of everything that's already come down. Where it suits the roof, we follow up with a treatment to slow regrowth. You'll get photos of every slope and gutter run before and after.

Written by Hawkes Roofing, roofers based in St Albans who remove roof moss by hand across Hertfordshire, Buckinghamshire and north-west London. Last reviewed 26 October 2026.