New Home, Question about insulating Garage

[crazy1323]

I just bought a new house that comes with a detached two car garage. Right now the garage is just bare studs. I want to insulate it and put in heat and AC.

I want to use closed cell foam to insulate the garage. I want to spray the underside of the roof and condition the storage space in the top of the garage.

Will I have any problems with moisture? I am concerned about bringing a wet car in and trapping all of that moisture inside the garage. I do not want to run the garage HVAC all the time, only when I will be working out there.

 

[e-tek]

Seems I answer this same question every week! If you're going to have moisture (wet cars, snow, water) inside a garage, you need to stop that moisture from going into the walls (vapour barrier, well sealed, oil-based paints) and run a fan with make up air (edges of OH door will suffice), to get it out and dry the area. The fan can be on all the time (mine is) which also removes heat in the summer (from car engines) or you can hook it to a Humidistat, whcih will run until the humidit lowers to set level. Hope that helps!

Once again, someone didn't put in their location..... The anwser depends somewhat on your weather conditions, but the above still holds true.

 

[crazy1323]

I am located in Memphis, TN. It get pretty hot in the summer here. We have very high humidity too.

 

[e-tek]

I'm only a little surprised no-one else has chimed in - must be the least-visited forum here! Everyone's in Free-Parking....

A small fan running all the time takes very little power and will control the mositure that comes off a wet car. However, if your atmospheric moisture (humidity) is really high then it would only get it to equilibrium with that - which should be OK. You can get duct fans (that are meant to move air further along duct work) for very little. Cut an 8" hole through the wall and insert, with a rain cover on the outside.
I'd sooner put it on a timer or turn it on when you bring in a wet car and leave it on overnight - as the humidistat relies on condensated water and may not turn on in all instances - especially when you want to draw the hot engine heat out. I find I use our fan as much for that as I do when snow is melting off the vehicles.