Garage, attic, basement, and crawlspace locations are a similar problem. Its a dew point issue. The dew point temperature of the air contacting the cool surface is above the surface temperature, condensation. Any insulation that does not have a perfect vapor barrier on the wet side of the insulation will allow condensation on the cool surface. Solutions: reduce the dew point of the air on the cool surface or warm the surface. Ventilation introduces more wet air. Ventilation is not a solution to this problem! If insulation with the vapor barrier on the warm side impossible, consider dehumidification. Basements and crawlspaces for sure because mold control is necessary in these spaces. Crwalspaces need plastic ground cover and closed vents. For tough attics, close vents and dehumidify.
Originally posted by karsthuntr
I have a customer with the same excact problem. I know the humidity in the garage is really high and suspect that is the culprit. The cure would be to increase ventalition in the garage, but not sure how to go about doing this. I guess I'm curiuos as to what the solution would be.