How to support a desk without legs or brackets

deskmounting

I plan to build a floating desk with the following dimensions: 75"-79" long and 22"-24" deep. I plan to mount it to concrete wall(see Image). My Preferred material is MDF.

enter image description here

The desk intended for use as computer desk and writing-reading desk. The load on the desk will be mainly consists of: monitor screen, books, laptop and so on.

My goal is to create a strong and stable desk that can support not only the load described above, but also beyond that(specifically: adult leaning on the desk with his arms).

My question is: How can I support the desk without any legs or bracket?

EDIT: There is a similar question to my question on the site(HERE) but I think the solution proposed does not fit my question. Since to my opinion the proposed support in solution is too weak for my purposes. I'm pretty sure that if I will lean down on the edge of the desk with time not only it will created a 'belly' but it will damage the Alum angle stability (maximum torque). I think the proposed solution is better suited for shelf that functions as a desk, and I want a strong desk that can support for example a person sitting over it.

Note: I do not care if the most of the entire thickness of the desk(based on the design offered) would be a hollow, as long as it's does not exceed 5''.

Best Answer

This is a pretty standard construction for floating shelves/counter top.

  1. enter image description here mount a cleat to the walls (the third wall is omitted for clarity sake). In this example it's a 1x4 but that will depend on how much weight it needs to bear.
  2. enter image description here Create a torsion box leaving a socket around the edges to accept the cleat.
  3. List item mount the unit and apply a backsplash to cover the gap where the back and sides meet the wall. It's not impossible to scribe in a three sided surface but it's a tremendous pain in the neck.

I would recommend MDO over MDF as it has the strength to weight ratio of plywood but the surface of mdf. As for the thickness w.r.t the strength of the front edge... this is really pushing the limit of what you can support without a leg or integral steal beam and not experience serious deflection or failure.

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