I've removed the raised hearth in front of our fireplace. The fireplace floor is raised 12". If I remove it I can slide a stove into the fireplace opening. The fireplace floor has a layer of (red) brick on top of 2 layers of gray brick that are 4"x17". I've slightly loosened one of the red floor brick and don't think it will be too hard to remove all the floor inside the fireplace. Has anyone removed their fireplace floor and redone it? I would have about 1 1/2inches of space to rebuild the fireplace floor to code. (3/4" of sub floor and another 3/4 " for the wood floor I am installing in the room). I think Micore 300 at 1/2" is rated at 1.1R value so I don't think there is any problem getting enough floor protection. What about removing the entire metal heatilator jacket? I've poked and prodded and don't think it would take too much to remove the jacket. Then I would rebuild the sides of the fireplace, if necessary, with micore and stone or tile or?? or just rebrick it. Would do this for a nicer look and I'd have an even better path to the flue and chimney. On the other hand, where does one stop?