Expert: Dan Griffin - 2/24/2008

Question
Hi Dan, I'm going to build in part of my garage and make a guest bedroom. One end of the slab is about 2" low and the other end is 5" low. What is the best way to level the floor. One person told me to float it level with cement on top of the slab and another told me to run stringers and attach them to the slab and then floor it with 3/4" plywood. Any suggestions would help. Thanks---  Ken
Nice to hear about your Barber Shop Quartet. I play the piano in a Dixieland Band. Love the old music.

Answer
Ken,
Either method will work, it depends more on where you are most comfortable.  3/4" subfloor will be a bit skimpy even on 16" centers.  It will be fine for minimum loads and carpet, otherwise you may want to look at 1 1/8" tongue and groove decking. Capping the slab will give a floor that will take ceramic or any other flooring.  Make sure you cut contraction joints into the new slab.

I am surprised that your garage slab isn't down one or more steps from your finish floor.  It is usually a requirement.