On 3 Mar, 16:09, RobertL wrote:
I need to get up on the roof of my garage to remove the moss. *

Get a platform (three-way convert-a-ladder - great things and well
worth Aldi's 60 quid) and stand alongside with a long rake.

No way will I use crawling boards on a small-corrugation asbestos
roof. The stuff is brittle as anything, and even if you don't go
through it, there's a risk of cracking it and resultant leaks.