Air gap between slab and foam insulation risky?

I have a bath/shower room that will be built on top of a concrete slab poured between foundation stem walls. The slab will be above grade, finished to the same… I have a bath/shower room that will be built on top of a concrete slab poured between foundation stem walls. The slab will be above grade, finished to the same…Read MoreGreenBuildingAdvisor