chabbo wrote:confirm that 2x4 framing 12" OC is sufficient, utilizing 3/4 inch plywood
I personally guarantee you'll be fine, granting the pinning to the concrete holds and the studs hold to the footers. If the 2 x 4's break and the plywood fails, you contact me and I will send you a check for the price of the wood. How's that for confirmation?
You will have about 210 pounds per sq foot by the math. You have plenty of strength for that. I have no feel for how much "outpush" the coal has though. Where the wall plywood comes down onto the angle, if it bows the walls 3/4" you will have a crack there. I don't think you'll have that problem as long as the studs are very secure to the footings. Hmmm... if the wall plywood went to the floor as I first mentioned, then you'd have the strength of the plywood ON the footer. Also, if any dust leaked, it's in a closed dead space anyway.
I'd like to hear other opinions too!