Home>Discussions>INSULATION & HVAC>Attached Garage condensation
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Ranicamp
Attached Garage condensation

Hi, I live in Minnesota and I have a double door garage that is attached to the house. 2 years ago I hired a contractor to mud and tape the garage as well as paint it, I also replaced the garage door. Since than I have noticed during the winter months that I have terrible condensation problems, looks like a rain forest! I know the exterior door and window needs replacing also but I did not have this problem before. Any reasons why? What can I do to rectify this problem. Thanks.

MtMan54
Re: Attached Garage condensation

Hi, Was a plastic vapor barrier installed at the same time? Thanks

KShenefiel
Re: Attached Garage condensation

My guess is that you somehow managed to get the exterior walls and doors of the garage more tightly sealed than the adjoining wall to the house. Water vapor flows from the house to the the cold garage where it is trapped and condenses on the coldest surfaces.

Make sure the door into the house and adjoining wall to the house is well sealed. Or adjust the weatherstripping on the overhead door for a looser fit. Or insulate the doors, windows etc. and keep the garage heated.

HoustonRemodeler
Re: Attached Garage condensation

The cold air is condensing on the warm surface. Is the insulation properly installed with vapor barrier before they drywall was installed?

bill
Re: Attached Garage condensation
HoustonRemodeler wrote:

The cold air is condensing on the warm surface. Is the insulation properly installed with vapor barrier before they drywall was installed?

Cold air can not condense on a warm surface. warm air however can condense on a cold surface.

ordjen
Re: Attached Garage condensation

Minneasota can be very cold. Those walls are really cold at times. I assume you park in your garage and often bring in a lot of slush frozen to the underside of the car. The car in the moment you enter the garage has a lot of stored up heat energy from the engine and exhaust. This raises the temperature of the garage temporarily. The slush melts creating lots of moisture which then hits the very cold walls.

Are your walls actually insulated, or just drywalled? Builders often don't insulate the garages, but hang drywall for aesthetics and fire purposes. The common wall to the house must be totally drywalled according to building code. The ceiling too if the attic continues over the living space.

What to do: Insulate the walls if they are not. Raise the temperature in the garage. Keep air moving in the garage. Don't bring your car into the garage in winter when the bottom is covered with slush.

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