Large U countertop support

[Sam Harper]

I need to build a desk in with minimal support under it.
it is in a nook so it is adjacent to the wall on 3 sides.
I plan to attach to all of the wall studs.

It is for a desk at a nurses station. it will most likely just be used to fill out paperwork, but somebody might sit on it. I want it to be able to handle that.

I can put legs on the long part of the desk.
I have considered a steel frame and/or torsion box.
I am open to any material suggestions.
I plan to use mdf, but I like plywood a lot better.
I wanted any ideas because I'm not sure how to best engineer this.

[Jim O'Dell]

How many seating positions will there be at this? 2, 3? I'd build some triangular bracing back to the walls at 30 to 36" intervals for structural support. The end caps you say will be decorative. How about making end panels that go to the floor and incorporate places to hang clipboards or other items they might use often? Or angled organizers for paperwork? The end caps could be for support that way. Just some random thoughts. Jim.

[Sam Harper]

The end panels are structural with shelves that are open to under the desk.
Honestly I'm not sure how many seating positions.
I think 2 or 3 on the longer section and 1 little one on each short section.
One person will be using the desk most of the day, but the charts will be above it so people will be sitting for a minute or might just stand in front of the smaller sections and use the surface for charts and paperwork.

[Jim O'Dell]

If there were only going to be 2 chairs, I'd put a brace right in the middle of you long section, then another angled at the corners. That way 2 people could sit without banging their knees, and have almost 4 feet of room each. If there were going to be 3 chairs, I'd put 2 braces on the long section, giving the center position a little more room, and let the other 2 chairs be on the sides. If there are going to be 5 chairs, I'd make sure they were either very very good friends, or that I was out of there when they started picking the places they were going to sit. :eek::eek: :p
Have you decided where you will make your breaks in the sections of the top? If you can get a 5 X 8 sheet of MDF, and there are only going to be 2 chairs, it will be easy to get all of the top out of one piece, spliced together in the middle of the long wall on top of the brace. If 3 chairs, I'd piece it to fit again at the 2 braces. Once the top is put together then braced, you should have no problem putting laminate on it without seams since it is available in 5 X 10 foot pieces. Should even have enough for the edges out of the one piece.
In other words, I'd want to verify how they are going to use this and plan the baces accordingly. I'm sure there are some commercial braces that would negate needing to worry about this. I've just not looked for them. Jim.