A guy at the lumber yard in Spokane talked me out of 3/4 plywood in about 90 seconds
I was loading up for a bookshelf build two Saturdays ago and had a cart full of 3/4 inch plywood when the yard guy walked over and asked what I was making. He said for shelves that short I was paying for thickness I did not need and pointed me to 1/2 inch plus a face frame to keep it from bowing, which saved me about $40 on the sheet. How do you all decide when to size down material versus just overbuilding it so you sleep at night?
Did the yard guy ask what your shelf span was before he steered you to 1/2 inch? A buddy of mine built a run of built in shelves in his den and got the same speech from a guy at his local yard. He went with the thinner stuff, screwed a face frame on the front like he was told, and it looked sharp for about a year. Then he loaded the bottom two shelves with hardbacks and they sagged in the middle anyway. He ended up adding a strip of hardwood to the back edge too. Cheap fix, but he said he wished he had just run the numbers on the span first instead of trusting a quick pitch.