We raised the roof on our home several years agoWe didnt remove the original roof to save moneyMy mothers bedroom quarters are the farthest from the Central Air condenser outsideUpstairs in all our rooms, but especially hers get sooo hotShe has the thermostat in room for the upstairsIts set at 75 degrees but it is always about 80 degrees in her roomI know its summer out but I would think the AC unit would be able to keep up since its running continuoslyThere is no ice formation The AC is set to 80 downstairs with the kids running in and out all dayCould the 1st roof be retaining th heat? Should be install fans at either end of the house? We were told it would cause an updraft and we would loose the cool air we are gettingHELPP!!!!
If you intend to use it between the floor joists, you are just as well off with fiberglass batts and drywallSpray foam will work as wellIf you want to use rigid foam boards you would install them like drywallIf they are cut and not sealed correctly they are as good as uselessIt is actually better to insulate and air seal the basement walls and rim joistThat is where most of the heat loss will occurWhichever you opt for, make sure you know the fire code and fire rating of your insulation if it will be installed anywhere near mechanical equipment (hot water heater, furnace, etc.) For more info, check here: apps1.eere.energy /consumer/yo.
Insulating between floor joists will only make the floor colderBasements and crawl spaces should have tghe prmieter walls insulated, not under the floofrsThat way any heat radiating from the ducts will rise and help heat the floor.
I have rigid styrofoam insulation on the walls in my basement, and I don't see any reason why you couldn't put it between the floor joists, but it would mean a lot of cuttingIt may be possible to use that new product that you can spray on - when it sets it is almost like styrofoamIt expands when you spray it onThat would be my first choice now with anything like thatI don't know how it compares in terms of cost and I don't know the correct name for itI've seen it quite a lot on those Flip this House sort of shows.
