Dan,
Yup they are fiberglass. I have used fiberglass restorer then sprayed with aerospace 303.
Keeps the white off of the side of the coach from the roof degrading
Thinking about putting a coat of Dicor roof coating down after next scrubbing
Others use Bus coat and or a marine coat.
At this stage I do not mind getting on the roof but If dont have do I dont mind that eirher
Greg