any tips ?
As we used to say............sky hooks ::)
Seriously though I was about to do mine this summer, managed to wire brush the loose muck & lichen off but never got round to actually painting it.
My plan was to use a brush tied at right angles to a stick/cane to do the ridge.
I also considered getting a sheet of cardboard the same size as the roof glass panes and spray!
But as I said I never got around to it :'(