Bed rack support

For those of you who have built bed racks, did you build supports down the bed bottom on our trucks? Seems second gens have alot of problems with bed rails being weak under weight. Are the rails good enough to support a rack with rtt and other items or should I plan on supports down to the bed bolts?

 

All my bed racks and camper shells have always sat on the rail tops. I prefer full length base - for a rack typically angle iron.
Even the common lumber racks sit on the rail tops...
IMO the weak spot is the tailgate end of the bedsides - Most rack legs angle outward from top to bottom / \ - which ends up pushing outwards - under abuse your bed sides (at the tailgate) begin to look like this \__/.
Google 'truck bed stiffeners' -