I get up on ours when washing the roof very well which is once a year, sometimes every other year. I really don't like the idea of 180 pounds of weight concentrated on a 3" x 8" footprint. So I keep my time up top to a minimum. Some years I'll use a brush on a pole and stay on the step ladder. It depends how dirty it got, and how hard it is to clean off. Stored indoors helps a lot with dirt control.
I do seem to be a bit extreme compared to just about every other PC owner. I am simply afraid of damaging something because of the light weight and thin materials used up top.
