Garage condensation issues. Looking for help

[gungho_15]

I will explain my situation best I can with a lot of details.

-Western Canadian two storey house. 35 years old

-Attached two car garage. Garage 22feet wide, by 20 feet deep

-Kitchen area above garage, roughly 12 feet by 12 feet area, balance of are is deck

-16 feet of North wall and 12 feet of East wall are living quarter walls. 8 feet of east wall, 4 feet of North wall, all of South wall are exterior walls and all of West (double garage doors)

-garage used to be open carport, so its not heated, It had cedar siding on walls, and cedar tongue and groove on ceiling. West was filled in with doors, South was famed and sided, East framed and man door, north framed and man door. Cedar was removed from walls, and ceiling.

-Interior walls are all proper vapour barrier on warm side and insulated. All other walls no insulation.

-Kitchen area (12x12) on ceiling has 5 inches of spray foam. Rest of ceiling open stringers

-Deck extended off front of house by 18 inches, where before it was flush to front of house.

Cars always parked in garage. Wet and dry.

Last winter, I noticed moisture problems on the ceiling of the garage. It started to cause minor discoloration of the ceiling area and walls, mainly near the front of the house where the garage doors are. It ended up being minor mood which was rectified with bleach. This summer I added a 36' long by 18" tall window in the rear east wall beside the man door. It actually helped with the hot summer. I have also ordered a Dragon 235 cfm garage vent fan to install in the middle of the south wall. Im not sure if I am missing anything. I want to drywall the remainder of the framing, but want to make sure I'm not missing anything first.

Thought of this after I wrote. Not sure where it would fit in. As I said I extended the porch out 18 inches off the front of the house above the garage doors. I installed 3 LED recessed lights to the soffit above the garage doors and finished with cedar tongue and groove. The moisture seemed to like the area between the joists above the garage door header. I ended up pulling a strip of tongue and grove cedar off to improve ventilation. Not sure if it made huge difference or not.

Sorry for long post, but wanted to provide as much detail as possible. PLEASE comment, ask questions, or give advice.

Thank you all in advance!

This thread is also in the HEATING and AC section. It was suggested I move it to here.

 

[gungho_15]

nobody?

 

[tcianci]

Your main problem is that your garage is too small!!!. Everyone knows that great big garages with space enough for all out junk and a few hot rods never have moisture problems!

 

[mygarageone]

Have you talked to a builder at all , one thing I would consider getting ahold of a professional insulation company , it may be warm air in the garage hitting the cold walls or ceiling . I am a plumber so I really do have any ideas .

 

[kbs2244]

You need ventilation.
Put in the fan and see what happens.

 

[gungho_15]

I do believe the cold air coming in from the front of the soffit could be part of the issue. Will have the fan next week

 

[bazzateer]

I'd insulate and vapour barrier all the walls and ceiling where not currently done. Also ensure good ventillation whether by a fan or otherwise.

 

[gungho_15]

I'd insulate and vapour barrier all the walls and ceiling where not currently done. Also ensure good ventillation whether by a fan or otherwise.

Thanks for you response. I was advised 100% to not insulate any of the other walls as the space is not heated and no intention of being heated. I was told insulation and vapour barrier would add to the problem. This is why Im asking these questions. No real definitive answer, except for ventilation, which is apparent....lol

 

[bazzateer]

Fair enough but condensation forms when the warm air hits the cold wall. If the wall is insulated it will not get so cold on the inside and a vapour barrier will prevent mositure from reaching the insulation/wall. This alone should reduce the chance of condensation. Add some decent ventilation and you should see an improvement.

Certainly sort the ventilation first as this is probably the cheapest and easiest thing to do.

 

[gungho_15]

Fair enough but condensation forms when the warm air hits the cold wall. If the wall is insulated it will not get so cold on the inside and a vapour barrier will prevent mositure from reaching the insulation/wall. This alone should reduce the chance of condensation. Add some decent ventilation and you should see an improvement.

Certainly sort the ventilation first as this is probably the cheapest and easiest thing to do.

Fair statement.

I am really beginning to think its due to my open soffit and ceiling. I currently have no drywall on the ceiling. The floor joists run directly out the front and its open to the outside soffit. Im thinking my problem is when I put the wet cars in the garage, the warm moist air rises into the joists and meets the cold air at the point of the soffit where I notice most of the condensation collection.
I think once the garage is more tight without huge openings and the vent fan installed will help. I never had issues when the ceiling was tongue and groove soffit. It really never started till that area was all opened up to the outdoors.

 

[xyster101]

I am having a hard time picturing your setup from all the descriptions and I would think other people do to. Can you post some wide angle shots of said building and problems.

As stated above, any time cold air meets warm air there will be moisture. If you don't have a vapor barrier on the warm side of an insulated wall, you will have moisture traveling through that area.

 

[gungho_15]

Cant figure out how to add pics I just took...lol

 

[gungho_15]

 

[gungho_15]

 

[gungho_15]

 

[gungho_15]

 

[gungho_15]

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[wdrumheller]

Well, I have to swear by good dehumidifiers in a situation like this. If you're bringing wet and dry cars into that garage, it is going to get moisture.

Most good dehumidifiers have fittings where you can attach a hose to them, and run it through a wall to the outside, and never have to empty them. I got on craigslist and got one for $100 that was worth $190, and it's been great.

http://www.amazon.com/dp/B00AU7GOIK/?tag=atomicindus08-20

This is an idea, and an opinion, and could be completely wrong.

 

[xyster101]

You have a mixture of insulation going on. I agree with the above statement to insulate the whole area with the vapor barrier facing into the garage. While not heated, a car gives off a lot of heat and will warm the room a few degrees. I know my attached garage at my old place was insulated and I did not have moisture problems. My attached garage would get cold, but it always seemed to stay just above freezing. Insulation around the soffets will help tremendously. That is a direct link to cold and I assume you get a lot of condensation in that area.
A dehumidifier would help too. As a bonus it will generate heat and keep the temp a few degrees warmer, as a negative they consume a fair amount of electricity. That 30-pint from Amazon should be ok for that space.

 

[JakeKohl]

Where was the mold problem? Was it on the entire ceiling, just under the kitchen (insulated area), or just under the uninsulated porch area? Was the mold on the surface of the drywall or in the enclosed space behind the drywall?

edit...I see you said that the moisture liked the header area over the garage door.

You've got a lot of stuff going on in there and you may want to get a couple of insulation contractors to take a look at your situation...it's a pretty unique combination of structures and you are in a climate with big changes in temperature throughout the year.

Venting that area like you have done will probably help but there should be an insulating solution that will solve this problem. You've got factors with snow and cold, hot and humidity, and late day sun (doors facing west) to consider. Air currents coming in around the garage doors could also be contributing. I'm willing to bet that it's the warm moist air coming off a snow laden car that's rising to the ceiling and condensing when it hits that cold uninsulated wall and porch floor. Your garage doors also look to be insulated and I bet that insulating the rest of the non-insulated portions of the garage will probably fix the problem.

 

[gungho_15]

You have a mixture of insulation going on. Insulation around the soffets will help tremendously. That is a direct link to cold and I assume you get a lot of condensation in that area.
A dehumidifier would help too.

You are right about the insulation. it is correct with the building code here and required amounts.
As for the soffit, that is where most the moisture accumulated. It did help once i I I removed some of the soffit to help with air flow.
Dehumidifier, I think thats out of the picture. It would never keep up with my scenario. I can be in and out of the garage up to 12 plus times a day/night with my car. So the amount of moist air it will be exposed to would be astronomical.

Where was the mold problem? Was it on the entire ceiling, just under the kitchen (insulated area), or just under the uninsulated porch area? Was the mold on the surface of the drywall or in the enclosed space behind the drywall?

edit...I see you said that the moisture liked the header area over the garage door.


You've got a lot of stuff going on in there and you may want to get a couple of insulation contractors to take a look at your situation...it's a pretty unique combination of structures and you are in a climate with big changes in temperature throughout the year.

Venting that area like you have done will probably help but there should be an insulating solution that will solve this problem. You've got factors with snow and cold, hot and humidity, and late day sun (doors facing west) to consider. Air currents coming in around the garage doors could also be contributing. I'm willing to bet that it's the warm moist air coming off a snow laden car that's rising to the ceiling and condensing when it hits that cold uninsulated wall and porch floor. Your garage doors also look to be insulated and I bet that insulating the rest of the non-insulated portions of the garage will probably fix the problem.

I like your answer, thanks. Good info from everyone. I think I should insulate, vapour barrier, and sheet exterior walls. Possibly insulate and sheet remainder of ceiling. Not sure on insulation though. Still mixed answers. I am stlll going to install the fan. I can say that I never had a window in the garage till this summer. The fan with window should keep air moving. I believe once I tighten up the garage to alleviate all the little cold leaks, that the fan and window will help. Thanks again for all the great feedback. Keep it coming...lol

 

[jvitez]

Use Roxul for insulation. It's water proof, critter won't live in it and LOVE the cushy comfort of fibreglass batts, has a higher R-value and can be custom cut to fix exactly how you need it. It's a bit more expensive but much better overall.

 

[gungho_15]

This is a good article!

http://www.phbi.ca/documents/garagemoistureissues.pdf

 

[911mike]

I keep a medium size fan going all winter long and it makes a huge difference. My floor is epoxied too.

 

[gungho_15]

I keep a medium size fan going all winter long and it makes a huge difference. My floor is epoxied too.

started today insulating and vapour barrier. Tamtech emailed me mack today and said the fan will exchange the air every 15 minutes. The link I pated above taught me a little as did you guys. I will see how the winter goes and judge accordingly. I truly believe eliminating the large air source in the front on the ceiling will be the difference