I am installing 16' desktop to a concrete block wall. The back wall and one side will sit on a 2x4 ledger. The opposite short side will be a solid plywood panel to help support weight.
The top will likely be 3 hollow-core doors topped with laminate.
As this will be used like a desk for multiple people, I want the front of the unit to have no support legs to be in the way of chairs/legs. I do plan to have some angle supports cut from plywood to help distribute the load (think right triangles, but with a with a significant crescent removed from the hypotenuse to help for knees clear)
At the front, I could use a 2x4 on edge to make a rail to help stiffen the edge, but I thought that perhaps a piece of box steel or angle aluminum would do the job with less deflection and a lower profile.
What size angle or box tube would accommodate the 16' length with the smallest vertical profile and least deflection?