I am remodeling a recently purchased home. The previous owners converted the back porch into a bathroom. (good idea) They fed the plumbing through the floor joists, put some foam insulation below the joists (most of which is falling off) then they added electric baseboard heating, cut some vents in the floor and crossed their fingers that heat would fall instead of rise (bad idea). There were a number of close calls with pipes freezing.
Currently I have the floor, subfloor and all walls removed. What do I do now? I could try more foam boards under the joists, (there is about 3-4 feet of open air before the ground former porch remember), force air in between a joist and vent up through the floor? This would be ok for the water pipes in that joist but what about when they cross over to other joists that don't have air forced through them?