[mtlakejim]

I am considering thick (as in ridged) aluminum sheeting supported by additional bracing as needed. I particularly like that idea in areas where having easyly removed panels would improve access to mechanical components such as sewage valves and water lines

Obviously not a cheap project but I think worthwhile early in ownership on a brand new rig

I certainly agree about adding insulation!! Perhaps foil backed styrofoam cut to fit between flooring supports?