If your trailer came equipped with a ladder, the roof can probably be walked upon. I have been on our roof, and it 'springs' a bit. I don't go up there unless I can't reach whatever it is I'm doing from a ladder placed against the side of the trailer (I have padding taped to the ladder to protect the edge of the roof) A little more difficult to scrub the roof from the ladder, but, with an extension handle on a medium bristle brush, I can do 1/2 of the roof from each side. I'm not a really light guy, so I figure I'll stay off the roof as much as I can! JMHO - FWIW