Expert: Jim Lyon - 12/19/2008

Question
QUESTION: I live in a condo in Indiana.  My bedroom is over an completely insulated and drywalled garage but floor and room is always cold. I replaced a light downstairs opposite side of the condo and when I took it down air rushed in. What do I do?

ANSWER: Hi Nancy, I might be able to help you but I need to ask a few questions
1.) Does your garage extend past the bedroom wall above?
2. Any idea when the condo was built?
3.) Why do you say the bedroom is completely insulated?
4. What type of heat do you have? Forced hot air, or hot water baseboard or other?
5. Are there any soffit vents on the overhangs of the condo?
Any idea how much (thickness) insulation is over the bedroom ceiling? You might have to enter the attic access usually in a closet to measure.

Thanks, this will help me.

Jim Lyon

---------- FOLLOW-UP ----------

QUESTION: 1. a small "roof" approximate. 4' and I got up in there and spray foamed the "flat" or end of the wall to the house.
2.They are no more than 10years old I believe a little less
3. The garage is completely insulated.  I drilled 2" holes in the drywall and say insualtion on both sides and ceiling.
4.Gas forced air
5.yes there is a soffit on the overhang of the garage and at the roof line.
By the way I pulled back my carpet in my room and drilled a 1/2" hole and cold air blows in.  Thank you so much for your help, Nancy

Answer
You obviously are addressing the right issues here. As you are no doubt aware, one answer is eliminating all sources of air infiltration starting with the most obvious ones. Sealing any penetrations in the wall/second floor joist space as you have done is critical. What about the other end of the floor joists? Are there any other penetrations such as a first floor bathroom fan?  Also, sometimes a plumbing vent or water heater vent may extend through the floor joist space and then up through the roof. These should be caulked where they go through the ceiling.
Light fixtures in the garage ceiling? The boxes should be caulked where the wiring enters and also around the edge where it meets the drywall.
It is likely that wires pass from the outside garage walls up into the floor joist space, this would provide an air path that would unfortunately be hard to find and seal.
I would like to know if you find any additional penetrations.
Regarding insulation, the bedroom is basically a box that has almost all sides facing the exterior/ cold spaces. As such there is enormous increased heat loss compared to any other room in the house. We have added a layer of framing and insulation below the floor in the garage below, and re-drywalled, which helped tremendously. Typically the heat ducts have to extend across the garage ceiling and this introduces a lot of heat loss, adding insulation here in some way such as framing/insulation/drywall may also help. Rigid foam board with drywall over is an option if space is at a premium. Also try to balance the system by closing down airflow to other areas of the house, to increase the flow to the bedroom. A  
Keep me posted as you work through this and I may be able to help with specific advice.

Jim Lyon