I have been contemplating how to address this issue since I bought this house and discovered it. The floor in front of my fire place is raised slightly. When I went into the basement to see what could be causing this I found that the fireplace was simply placed on perpendicular floor joists. It appears that where the fireplace supporting joists tie in to the other floor joists they are lifted where the metal brackets are that attach them. My guess is that they added the fireplace to the design after the basement was poured, therefore the need to push out that part of the floor. The question is how to lower this part of the floor and permenantly, properly support it so it doesnt happen again. What do you guys think? Should I dig a pit outside the basement put some type of footing for a jack and just lift it using some type of header? Should I go from the inside and try to pull it back down into place? One part of the quandry is that there is a vent window directly under the chimney, (great planning on that one). It would be a bummer to loose the little bit of light that lets in. But I would accept that for a level floor. Any ideas at all are much appreciated.