I am planning on gluing engineered flooring over a concrete floor. When we pulled up the carpet we found and expansion gap in the middle of the room. The floor is level EXCEPT for a few inches on either side of the expansion gap, where it raises up enough to cause a board to see saw over the top. I've thought about putting down a leveling compound but I'm nervous about doing that as I may have to do a large area. Other than grinding down the concrete any other ideas. The flooring is 3/8" thick, i'm afraid the glue will not hold down the flooring over this hump. Help!