Gravel is being poured in to the house to support the basement concrete slab. Once the sub-rough plumbing was in place and gravel was put into the living area of the basement, L and I put in radon mitigation piping. It was difficult pulling the gravel out of the way to get the pipe at the right level, just below where the slab will be, so we built the radon piping for the area under the garage and gear storage room slab before the gravel goes in.
After the gravel is in, we will put in 2″of XPS insulation to give the radiant heated slab (about R-10) insulation, covered by a 6 mila moisture barrier taped. After that, the plumbers will put the radiant heat tubing in and that will all be covered in concrete that will be the finished floor surface of the basement.