I'm looking to install basement storage shelves. I plan to buy the lumber myself. I will be creating 6 2 foot deep 4 foot 6 inch wide shelves which will be piled 4 shelves high side by side including the space from the floor to shelf level 1.
Any suggestions on how to avoid sagging or any wood should work?
What spacing do you have in mind for the shelves and how do you plan to support them (and hopefully anchor them to the wall)? How much weight are you actually going to be putting on the shelves? Is 4'6" going to be wide enough?
24" d is going to be an expensive piece of wood and plywood might be a better bet anyhow. If you go with timber, I would think of at least splitting the width into 12" w planks.
Sure you do not want to look at ready to assemble steel warehouse or restaurant shelving or something? Seems like you might be trying to reinvent a wheel?