Doing the basement office in a 14 year old townhouse. Poured concrete, with nearly 10 foot clear space for ceilings. I want it warm to the feet as its going to be used every day. What kind of insulation should be under the subfloor and does the vapour barrier go to the warm side, like a wall, or to the cold side like other sites say? Do I do the walls first and then the subfloor, or should I do the whole subfloor first, with plates where the walls will go, under the OSB? Electrical and HVAC are all coming down from above, so there are no runs that have to under the floor.
Answer:
If your feet are going to be warm, you'll want to make a few changes. Raise the floor onto 2X6 joists with sporadically spaced 1" blocks under each joist. Insulate the walls' perimeter with at least R-28 bats and then apply vapour barrier. You can now lead 2 heats duct in there. They should be 5" diameter with a 4" open pant leg on each so the floor is heated and the 5" ones continute to the outside walls where heat grills will heat the room. VB goes directly onto the garage floor with no insulation above or below it. Do the floor first and then do the walls and ceiling.
