I had a repair done to the corner gutter of the roof near the bathroom window earlier in the week and the workman mentioned the amount of moss in the gutter below the roof at the back of the house. It's as I expected because that side of the roof does get a lot of moss as it has rough finished concrete tiles to which the moss can easily adhere. For years I've not let even the window cleaner go on the flat roof of the lounge extension, not since we had the roof repaired. It's only roofing felt and I didn't want him walking on it as it has gravel over it which is there as a fire retardant. So once a year for a couple of decades I've cleaned out the gutter and the one above the French windows.. It's easy enough to get on the roof. I just put my extending ladders through the beams of the pergola on the back of the house, then drag a second extending ladder up to put up against the top gutter. I always put a board between the feet of the ladder and the flat roof so they don't damage the felt. The beams of the pergola can easily take my weight as necessary, as I have to pass between two, to get on the flat roof. It was just a matter of scooping out the moss in the gutters to a bucket. Then flushing the length of both the top and the lounge gutters with a hose. While I was up there I scraped off three bucket loads of moss off the flat roof. I shall get some more gravel to replace that which came up with the moss. I had a good look at the felt where I could see it and it looks O.K. My wife wasn't at all pleased with me doing this job now that I've turned 80. But I wasn't going to take the chance of getting someone in who I'm sure wouldn't have been as careful with the roof as am I. I didn't repair the gutter on the corner of the house, although I could have done, I do have some long extending ladders in the garage, that would have really stressed my wife out, so I got someone in to do it.