I'm making a shelf that'll be 1 meter wide and 2.2 meters long. It's going to be simply supported by wire attached in four corners (with necessary 10 cm space from attachment point to the shelve's edge). I'm making it out of 18mm OSB board. Obviously I need to reinforce the board, otherwise it would sag too much on 2m span.
I want to keep the thickness of the shelf to the minimum. My idea is to sandwich the board between steel strips 40*4 mm. (Thus steel strips would act as universal beam's flanges, maximizing second moment of inertia constrained by overall width). The 4 strips will run along 2m edge through wire attachment points.
My questions are:
- Does it make any sense? Would it hold 50 kg total load with reasonable sag less than 1cm? (4mm thickness of the strips are taken from what's available on the market here. I'll not be bothered by the bulge that the strip will make on the surface of the board.)
- Should top strip be of the same width as the bottom one? Can I drop top strip altogether?
- What's the best way of attaching strips to the board? Screw both strips to the board/rivet top strip to the bottom through the board/ making threads in the strip for the bolt?