I have a client that converted an ag building to adwelling unit and built a sub floor over the existing slanting cement slab. The space between the two runs from 3″ to 6″. The forced air heater runs directly through this area with registers cut in anywhere he wants . – good idea – except that the homeowner did not insulate the cement and it takes hours to heat up the concrete adding to heating costs. I know that pulling up the entire sub floor and placing rigid insulation over the concrete will remedy this problem but would like to save the homeowner this expense. I could open up sections and push batts back in either direction but there is the issue of air contamination from material in the insulation batts.
I am wondering if there any product which can be placed in this area through small holes which will spread out over the concrete and insulate it.
Replies
Do you mean that the entire space under the second deck acts as a supply duct?
No, you can't mean that.
Regarding plenum beneath sub floor - Yes I do mean that the entire area acts like one big duct area. It actually does a good job of providing a very warm floor, AFTER the concrete beneath it has been brought up to temp - but that is the problem, the non insulated heat sink of the concrete mass.