We recently bought a house that was built in 1972. Most of the features were in original condition including the fireplace. Since the brick surface looked ugly we decided to teaer it down. In hearth area we found non-brick material underneath the bricks. They are a lot less porose than bricks but not as hard as concrete. They are extended all the way under the fireplace. We are wondering if we can remove them to get rid of the hearth...we want to make that area leveled to the floor. If you have any idea we appreciate your advice! Thank you.