This is a problem many people have. I built my house only two years ago, and checked that it is insulated to code (for MA) which is pretty stringent. However, I still had cold rooms above the garage. Let me briefly explain the layout.
My house is reasonably big (around 5000 sq ft including a fully finished basement). The design includes a three car garage, over which is situated the master bathroom, a dressing room, and a closet, plus part of the bedroom sitting area. Through two winters I had always noticed that the Master bedroom was slightly cooler than the rest of the house, and the bathroom, dressing room, and closet, much cooler, maybe 10 degrees or so. This is obviously annoying since my wife uses the dressing room first thing in the morning, and I (being and old guy) sometimes get up during the night to use the bathroom, or else go shower first thing in the morning in the icy cold!
So, what to do? Why should the area above the garage be so cold when the ceiling of the garage (i.e. the floor of the closet/dressing/bathroom) is insulated to code. Well, first of all I didn't think it through all the way and decided to buy a small in wall heater like the one shown from thermalinc or a similar company. This was maybe $200 including a thermostat, but when I asked for the electrician to install it he said it would be tricky, given that I did not have a sufficient dedicated breaker in the box to handle that. That's to say, I had never considered that it draws around 13A on it's own, and would required a 15a or 30a fused box. So, in the end it still lies in my garage waiting for a likely installation.
But, never fear, gentle reader! The answer was simpler! I solved it in two ways -
- The loss of heat was due to a space between the insulation and the floor. That is to say, the beams of the garage consist of 12" thick wood, but the insulation roll is only around 8 inches thick (R33) leaving a 4" gap. Now, since the side of the garage was exposed to the elements through only an external garage wall and siding, this gave plenty of room for the air to circulate in that gap, leading to a lowering of temperature and very cold floor tiles in the bathroom. So, I contracted a local insulation specialist, Bruin, to blow fiber into the gap between the insulation and the floor. In order to do this they had to drill small holes in the garage ceiling, 2 per beam, per garage bay, and blow the fiber into that gap, then sealing up the holes. In other words, they actually blew the insulation beneath the existing rolled insulation, eliminating the gap between the floor and rolled insulation, and incidentally increasing the R value (insulation value) by about 12. Cost? $1700. Ouch! But there were two guys working on it all day, so I suppose I can't complain too much...
- The second 'fix ' was to redirect the heat to the required rooms. Since each area has it's own heat outlet from the furnace, I was able to adjust the outlets (simply close them slightly) in the warmer areas, creating a stronger flow to the colder ones. Since the insulation was not leaking heat any more, this extra heat to the cold areas was retained and I now have a very warm above garage area. The dressing room and closet are about the same temperature as the Master bedroom, and the bathroom and toilet are actually noticeably cozy to walk into.
