How much static weight can a 2x8" board support when installed at an angle between two walls without sagging? I am building a shelf in a corner to hang a projection screen from. Each end of the stud will be supported by a bracket that is screwed through 1/2" drywall into a stud. See diagram. Along the span of the shelf there is no support. I want to hang ~40 lbs on the shelf not including the weight of the shelf itself which I estimate at another 20 lbs. Will this sag over time? If so, can I improve the strength by using two 2x8s screwed together?
Any structural engineers out there?
Any structural engineers out there?