we had the same issue with moss on our roof, constantly blocking our gutters and every time it rained they overflowed! no matter how many times I emptied the gutters of moss, they kept getting blocked again months later due to the moss falling off the roof into the gutter. we had the insurance guys come over to check it out and they recommended we get a roof cleaning company in every year and also one to do the gutters. after a lot of research we found out about the roof scraper tool from roofscraper.co.uk we bought this tool and then scraped the moss off. saved us a lot in recurring cleaning costs. the only thing is you need to apply a chemical after to stop the moss from growing back. these chemicals can be quite toxic so you must wear the appropriate safety gear!
