I live in a bi-level house with an unheated garage under the bedrooms. During the cold winters the garage can get as low as 38o. The ceiling insulation is good but, the sheetrock walls do not have any insulation at all! I am considering adding (my self) a closed cell foam. 1- Is this good option? If not,what is? 2- How difficult is this to apply? Is this a one man job? I understand winter is not the time to foam any walls in the Long Island area. Would appreciate any comments or suggestions. George
George, insulating the garage may help a little but the real issue here is that your HVAC system is not delivering enough heat to those bedrooms. Because those rooms have unheated space below, they need more BTU's delivered than rooms with heated space below. I'd have an heating pro take a look and determine if there might be a way to deliver more heated air to those spaces.
If you decide to insulate the garage walls, use paper faced fiberglass batts, and then drywall on top of the walls.