Oak shelf as desk

[tursut]

I'm planning to build a small office for myself in the basement. It will be a narrow plastered room, 120 cm wide, and I'm considering using an oak board fixed to three walls instead of buying desk legs. I'll put up strips on the walls to attach the board from underneath.

Do you think an oak shelf of 18x600x1200 will sag?

Something like this?
https://www.bauhaus.se/limfog-ek-18x600x1200mm

I'll only have a laptop on it and possibly a monitor in the future.

I'm trying to keep the budget down since I won't be there much, but if anyone has good alternatives, I'm interested.

 

[Gabbe1]

I think it might work, 18mm oak is quite stable and 1200mm is not that long, plus the board has support under three of the four edges.

 

[Gregx81]

It will work well. Make sure that the strips you attach to the wall hit the studs.
Should it unexpectedly give way, you can screw/glue more strips between the ones you attach to the wall, as "kottling".