I need to re-inforce my basement ceiling, which is my den floor. The basement ceiling measures 16 feet 7 inches by 40 feet. The floor/basement ceiling joist are 17 feet long setting on a block wall. How can I reinforce the den floor/basement ceiling with post so it will not move. I can hear anyone who walks thru my den. I was thinking about gluing plywood onto my floor joist then gluing another floor joist to the plywood. What can I do to make my basement ceiling more solid?