On 07/02/2021 10:35, AnthonyL wrote:
Over the past year or so quite a lot of moss has grown on my garage
roof. It is pretty much a very big sponge.

I've had some success by shovelling a few spades at a time into a big
container full of water and then gently fishing out the moss with a
rake. But that's nowhere near 100% effective.

Ideas and what should I do next?


Buy a big bag of ferrous sulphate from a garden centre or
agricultural dealer. if you have a concrete apron and the
roof discharges onto it, it will stain it though.