This fellow assumes that he knows exactly where the internal ribs are under the roof. With my camper I chose not to take a chance and added a rack using aluminum angle material and supported at the very outer edges at the sides of the camper. Even then my holes needed to be within 1/2" of the center of where the CAD drawings showed the metal framing was located.
His approach is also going to collect a lot of dirt and water over time.
Linear Mode
