Well, since I have an Ultralight (4350 Dry weight...used for reference only...no weight police stuff please!!), I will say that I walk on my roof. You just can't get around comfortably otherwise to really clean it. With the rubber coating and tennis shoes, it is not slippery, even when wet, but it is still a little freaky up there. I tend to be getting more uncomfortable with heights as I get older, but I can still deal with it fine. There are a couple of "soft spots" on my roof where I step, and then immediately "unstep" and then just work around. I don't know if I would go through the roof or not, but no sense in taking a chance. But for the most part, I feel comfortable (as roof strenght goes) in walking around my roof. I don't have a factory installed ladder either, so getting up there and back down, you have to be extremely careful...that's where one would tend to have the greatest chance of falling. My wife is always there to brace the ladder for me.