Hi! We are looking for feedback on converting part of our garage into a mud/laundry room. There are two small steps down to the garage (totaling 8"). We are looking to match the garage floor to the existing floor elevation of the rest of the house. This means we have to 'build up' the garage floor about 8". Any suggestion as to how (or if!) we build on top of the concrete slab. Thanks in advance!
I would check with your building dept. In my area we are not allowed unaccessible wood framed spaces to raise a floor. Venting would be one of the issues.I have seen it done in other parts of the country.
I'd look into pouring concrete. It would probably require some seperation from any existing wood framing, (walls, joists, etc) and it would be best to find out what is customary and allowed in your area. My area is semi arid so the way i might do it would probably not be allowed in Florida.
I've done this (in CA) with pressure treated sleepers (floor joists resting directly on existing concrete). You'll probably have fire separation requirements, but that's for the wall and door between the garage and living space.
When using sleepers, leveling the wood floor should be considered carefully. The carpenter had to rip-cut every joist a special angle because the garage floor slab had a double slope.