I have a 15'X15' addition on my house by the master bedroom. It is a concrete slab that is about 6 inches higher than the other floors. I want to convert it into my master bath. Is it possible to cut the concrete from the site of the tub, shower, and toilet , chip it out with a jack hammer all the way to the old locations of the same to conect the drains? Will this harm the structure or foundation? Since the addition is higher than the original I think it will drain well, and I have the space to re-vent each.