Outer Limits 4x4 Board

Does anyone have any idea how much weight I can run on my FRP top without having to fabricate an internal frame?

Looking at running Rhino roof bars with the flat strap type base that attaches to the roof in place of a gutter. Hoping to carry basic camping stuff (chainsaw, tent, mattress and maybe a fuel can)

Yeah, it'll carry all that stuff easy.

I had a full length steel custom job on mine that used to clamp onto the gutters, it weighed about 50kg and the roof could handle me standing on it with all the gear too, theyr'e a lot stronger than you think.