New home - garage moisture issue

[vette4]

Hi,

I am new to the thread. One of our must haves for a new house was a 2 car garage. We have just moved into our new house and cant use one of the garages they way we'd like because we found out it is very moist. We had stored some stuff in there for a few days and upon taking it out, everything felt damp. we have a raised ranch with one garage up top and the other garage directly below it around the back of the house. The one in question is the below garage. It is all concrete. Is there a permanent solution to correct this?
Thank you

 

[pattenp]

Not knowing the source of the moisture the best I can suggest is seal the concrete and to run a dehumidifier.

 

[Pen & Wrench]

Does the house ventilate into the garages in any way? Is there any way for moisture to migrate out of the garage?

 

[StreetGLi]

Where are you located? Is there high humidity in your area? Is some of your home's basement also level with the garage and do you find it's damp? Do you have climate control for the rest of your house? Is the lower garage below grade and if so is it a high moisture area?

 

[The Cobbler]

extreme cold followed by warming will cause condensation and high humidity

 

[vette4]

Does the house ventilate into the garages in any way? Is there any way for moisture to migrate out of the garage?

There does not appear to be any ventilation. The ceiling, floor and the side along the house are solid concrete. The opposite side has 2 windows that do not open and one is cracked.

 

[vette4]

Where are you located? Is there high humidity in your area? Is some of your home's basement also level with the garage and do you find it's damp? Do you have climate control for the rest of your house? Is the lower garage below grade and if so is it a high moisture area?

I am in MA. It is cold right now and we’ve been getting rain which has been unusual for feb. the lower garage is the same level as our finished basement but there a a couple unfinished rooms after the garage before getting to the finished part. That does have a mildew smell that I am getting checked out bc of the suspicion of hidden mold. I just added a dehumidifier to the unfinished basement area. I will attempt to add a picture to this forum when I get home tomorrow evening.

 

[Nivekdodge]

Is the lower garage below grade? Rain in the winter will go places it would never travel in the summer.

 

[StreetGLi]

If you're also having moisture problems with the other areas of the house it's possible it's a systematic issue with the poured foundation (poor waterproofing / vapor barrier). If you're having the home portion investigated the solution they come up with might be the same for the garage part.

You might also just be in a wet region and the parts below grade are more damp and that's just how it is. As I live in Canada things are a bit different and mosture is not often a problem in winter, however in the humid months ( or month.. ) my lower levels get damp and a dehumidifier runs non stop. That may just be how it is in your house / garage.

 

[AMCguy]

The Cobbler (post #5) touched on it. I'll give you a more detailed answer.

Presuming your garage is unheated here's what's happening.

At night your garage and it's contents reach their lowest temperature. During the day, the outside temperature likely rises above the temperature inside the garage. As long as you don't open the door to the outside there is no problem. But if you do open a door to the outside, the warmer outside air will enter and the moisture in it will condense on the cooler objects in the garage. It's a natural occurrence.

You don't have a moisture problem or a humidity problem. No amount of dehumidifying will help this. You have a temperature differential problem. If the garage and contents were as warm or warmer than outside when the door is opened, no condensation would be able to form.

You need to warm up the inside of the garage. If you can't afford to heat it full time, you need to warm it and it's contents up before you open up the door.

Glenn

 

[StreetGLi]

The Cobbler (post #5) touched on it. I'll give you a more detailed answer.

Presuming your garage is unheated here's what's happening.

At night your garage and it's contents reach their lowest temperature. During the day, the outside temperature likely rises above the temperature inside the garage. As long as you don't open the door to the outside there is no problem. But if you do open a door to the outside, the warmer outside air will enter and the moisture in it will condense on the cooler objects in the garage. It's a natural occurrence.

You don't have a moisture problem or a humidity problem. No amount of dehumidifying will help this. You have a temperature differential problem. If the garage and contents were as warm or warmer than outside when the door is opened, no condensation would be able to form.

You need to warm up the inside of the garage. If you can't afford to heat it full time, you need to warm it and it's contents up before you open up the door.

Glenn

My garage is unheated and I've never experienced this. It is insulated but my main doors are open alot. Why don't I have an issue with dampness?

 

[Jlbc212]

Just try running a dehumidifier. Other than the cost of the dehumidifier and the electricity to run it, it's the easiest and least expensive fix.

 

[Squ1d]

2 car garage on slab here coastal VA. My floors will be drenched on humid days. I just keep the doors closed as much as possible and run a dehumidifier. No worries.

 

[toolmiser]

My parents had an insulated 2 car garage that seemed to have excessive moisture. They found out if they opened the attic hatch and installed a screen that Mother Nature would keep it very dry. Of course this won't help when it is cold if you are trying to hold the heat.

 

[graffix000]

The Cobbler (post #5) touched on it. I'll give you a more detailed answer.

Presuming your garage is unheated here's what's happening.

At night your garage and it's contents reach their lowest temperature. During the day, the outside temperature likely rises above the temperature inside the garage. As long as you don't open the door to the outside there is no problem. But if you do open a door to the outside, the warmer outside air will enter and the moisture in it will condense on the cooler objects in the garage. It's a natural occurrence.

You don't have a moisture problem or a humidity problem. No amount of dehumidifying will help this. You have a temperature differential problem. If the garage and contents were as warm or warmer than outside when the door is opened, no condensation would be able to form.

You need to warm up the inside of the garage. If you can't afford to heat it full time, you need to warm it and it's contents up before you open up the door.

Glenn

This. ***** too when it happens. All tools/boxes get a wet coating on them. Just happened to me the other day. Temps had been steady around 30, and it jumped to almost 60'.

 

[vette4]

Thank you for all the advice. Hopefully we can find a way to make it manageable.

 

[bradleykd]

How long ago did they pour the garage floor?

I'm building a house and my garage floor put out some water for about 3 weeks.

 

[rburke65]

This is the reason you should update your profile with a location.

 

[Bretny]

Take a few pics of the up hill side of that garage. Do you have gutters that drain on the top side? What you have there is basicly a garage in a basement. There hard to keep dry in the northeast. Venting may help but only if its less humid outside... around here many times of the year its not.
Where did you move from?

 

[firebirdparts]

Dehumidifying it winter is unusual, but with a solid concrete structure, you have an enormous heat sink. The temperature of the structure lags behind what is happening outside. So if a warm front comes through with a lot of moisture, you would get indoor condensation, even in the winter time, until the building heats up in response to the not-as-cold weather.

In the summer, you might have condensation even more. So I would try to seal it up reasonably and then run a dehumidifier. I don't agree that dehumidification won't work. It does work. You just have to limit what you are trying to dehumidify to a closed space. You can't dehumidify the whole world.

 

[firebirdparts]

My garage is unheated and I've never experienced this. It is insulated but my main doors are open alot. Why don't I have an issue with dampness?

Probably just the weather. The heat sink is the concrete. Slabs on grade stay about ground temperature, but those concrete walls may get down to 30 degrees or colder when it's snowing. Then maybe the weather suddenly changes to 50 degrees and raining. Some places the weather changes 40 or 50 degrees F in a single day.

 

[vette4]

How long ago did they pour the garage floor?

I'm building a house and my garage floor put out some water for about 3 weeks.

The house was built in 1974. That's all I know.

 

[vette4]

This is the reason you should update your profile with a location.

Thanks. Just did.

 

[vette4]

Take a few pics of the up hill side of that garage. Do you have gutters that drain on the top side? What you have there is basicly a garage in a basement. There hard to keep dry in the northeast. Venting may help but only if its less humid outside... around here many times of the year its not.
Where did you move from?

I'll get some more pics later and will have to look at the gutters. We have always been in MA. Never had a garage "basement" like this before.

 

[crazylunker]

I have the same problem and have had the same issue since forever. It's condensation, whenever you have an area that is colder than the damp ambient air the moisture is going to seek a cold area to condensate(cold beer on picnic table). Either run a good dehumidifier when these weather conditions exist or install a heater(I have done both) the heater works great and spring and fall I keep the garage just above whatever the outside temp is expected to rise to. in the summer I run the dehumidifier. The place has been bone dry for over 20 years except for when I slack off on the thermostat.

No amount of sealing,painting or venting will stop condensing of moisture on colder areas when the humidity outdoors is high.

 

[gahrajmahal]

Your home looks like many here in Ohio where we build into the hillside. I would suggest that your French drain tiles placed below the floor level when the home was built are no longer working as intended. Long periods of rainfall saturate the ground around your house turning it into a reverse swimming pool with your foundation (block or poured) also is not as solid as when installed 40+ years ago.

I have a friend who I now refer to who has a knack for evaluating the slope of the land and creates surface Swales, long PVC gutter runs along with catch basins and other water clearing methods. We have one of those catch basins in the middle of our front yard along with a dry creek bed that only comes into play during the rainy late winter and spring. It is not helped by a dry summer where the dirt (clay mostly) dries up and shrinks away from the foundation exaggerating the problem.
Let us know what helps. Good luck.