Question: My husband wants to build a coal bin in an attached, unheated room to the house. The only info we can dig up on the net is that it should be away from any other combustibles (why?) and that a 4 x 4 area will hold 2 tons of coal. Most the info on coal storage seems to pertain to industrial storage. Could you help direct us to a book or web site that might give us instructions on how to, and what to keep in mind (safety wise) to build our own. Thank you again. Answer: ard coal has little chance of igniting from any source of combustion nearby, so I would not worry about this. Coal takes up approx 40 cubic feet per ton, so a 4x4x4 would only hold about 1 1/2 tons. As far as construction, plywood or boards placed on upright 2x4 studs makes for a fine bin. There are many different ways to construct such a bin...I'll dig around and see if I can find any diagrams.