Foam/Plywood floor over old slab?

I am rebuilding my garage/shed that appears to be ~50 years old.  It is a simple detached structure on an old slab.  I plan to replace with a very similar… I am rebuilding my garage/shed that appears to be ~50 years old.  It is a simple detached structure on an old slab.  I plan to replace with a very similar…Read MoreGreenBuildingAdvisor