We finally tackled the garage insulation this spring. Our 2-car attached garage was completely uninsulated — the shared wall with the kitchen was freezing all winter and the gas bills reflected it.
What we did:
- 2-inch rigid foam (R-10) directly glued to concrete foundation walls
- R-14 Rockwool batts in the 2x4 stud walls (shared walls with house)
- R-31 Rockwool in the ceiling (above the garage, below the master bedroom)
- 6-mil poly vapour barrier throughout
- New weather stripping on the garage door
Cost:
- Materials (foam, batts, poly, fasteners): $1,840
- Labour (2 crew, 2 days): $2,600
- Drywall finish on shared walls: $780
- Total: $5,220
First winter result: gas bill dropped about $68/month compared to the same months last year. We’ll hit payback in roughly 6 years.
The garage door itself is still the weak link — a 2-car uninsulated door is basically a 16x7 ft hole in your envelope. Looking at replacing it with an R-16 insulated door next spring.
Anyone else noticed significant heating cost drops after garage insulation? Curious what actual savings others have seen in the GTA.