Wood – How to support shelving

You would need to mount wooden strips along the walls that screw into the studs. Then the desktop sits on top of those strips and is fastened from the underside to the strips.

To achieve a more sleek look you could also consider the use of some lengths of aluminum angle iron that is screwed into the studs and into the bottom side of the desk surface.

Either type of mounting strip could be painted to match the wall to make it much less noticeable.

You will want to get this mounting strip along as many edges as possible and into as many studs as possible. Cantilever forces due to the open out side corner of the desk can be significant so make sure of two key things:

1. Make sure that the desk top material itself can withstand the cantilever forces without a lot of flex and breakage. (Unsupported thin particle board would not be a good choice).
2. Make sure that fasteners used up into the bottom of the desk surface get a good bite into the material.

Here is a picture showing a cross section of the wall and desk showing how the aluminum angle stock would be applied. You would likely want to use screws into the studs that are a bit longer than what I showed.

I'd suggest that you add a bracket on top for every bracket underneath. The effect of this (very roughly speaking) is that you'll double the stiffness of the bracket and double the effective length of the half against the wall.

The only downside is a bracket lump that dishes won't sit on, but if it was really upsetting, you could put a groove in the top surface to flush up the bracket.