Insulation

debd

When building a floor on top of a cement slab, can the insulation lay directly on the cement or does it need to be suspended in the air?

AKFloorguy

What type of floor and what type of insulation?
Laminate floors can go over concrete with a vapor barrier and good insulation/ cushion made for laminate floors- normally no thicker than 3/16".
If you are building a full floor with 12" joists or tgi's and a 3/4" plywood or OSB subfloor over them 24-36" of airspace is required and the airspace should be ventilated. Your local building codes and where you live have a little to do with it as well.