So we were getting ready to lay wood flooring in our bedroom and found that our subfloor had a "bow" in it. The bedroom is on the second floor and is partially cantilevered. Apparently the joists of the cantilever were not tied into the main joists correctly and have dropped about an inch to create a bow in the subflooring so the wood planks in the middle of room will never lay flat. Anyone have any ideas on how to fix? Is there a floor leveling compound available for wood... similar to what they use on concrete?