So I seem to have gotten lucky. My pole barn structure has been up about 1 year and been through all the weather cycles I can expect. It is 24x30, standard steel panels, no vapor barrier and the air moves through it pretty easy. I have not filled the space between the steel panels and grade baoard and it has a full ridge vent, plus it's missing a piece of gable trim I need to put up. The only time I deal with significant condensation is when it's cold, say 30 or below, and the temp rises like 15-30 degrees and the air is moist. My question is if I spray foam to the ceiling and fill all cracks and gaps etc, do I run the risk of the raining ceiling like I've heard some talk about? Right now the only thing I get is condensation in tools and such which I'm getting ready to take measure to help with. I'm just nervous I will seal it up and suddenly have a problem. Thanks, z
Question about condensation
- Thread starter Mr.wolf
- Start date
Randy in Maine
Well-known member
The condensation is likely from the heat source. Is yours properly vented?
I don't have a heat source yet. I do use a salamander when I work out there but the only time I have condensation is when the temp is cold, then goes up drastically and the air is relatively wet out. What I have now isn't that bad, I'm concerned once the building is insulated will that likely be worse?
Thank you. Really loving this place (GJ)
Thank you. Really loving this place (GJ)
Randy in Maine
Well-known member
Warm moist air condenses water out of it when it touches cold surfaces. I insulated my floor, the walls, and the ceiling really well. Lots of ways to do good insulation and spray foam is one of them.
Getting rid of the unvented heater will remove one of the things that is filling up the inside air with moisture as water is a by product of combustion with the salamander heater. Lot so ways to solve this one and a vented heater is one of them. So is radiant floor heat.
Even then you may have to use a dehumidifier to remove additional moisture. I have to do that sometimes, but I live at the beach.
Getting rid of the unvented heater will remove one of the things that is filling up the inside air with moisture as water is a by product of combustion with the salamander heater. Lot so ways to solve this one and a vented heater is one of them. So is radiant floor heat.
Even then you may have to use a dehumidifier to remove additional moisture. I have to do that sometimes, but I live at the beach.
tomroblee
Well-known member
Warm air will hold more water than cold air. A dehumidifier works by blowing the room air over a cold coil--causing the water to condense. When warm moist air enters your pole barn, any cold surface will function as a dehumidifier (the moisture in the air will condense on the cold surface.)
If you heat your barn sufficiently, there won't be any cold surfaces to condense the water. If you could completely seal your barn, the warm moist air couldn't enter and condense on your cold surfaces.
Air movement and/or ventilation will help to evaporate the condensed water as it forms, and will speed the process of warming the colder surfaces (which will reduce the condensation.)
Adding insulation without adding heat and/or ventilation is a mixed bag. We tend to think of insulation as keeping the barn from cooling down when the weather turns cold. It will also keep the barn from warming up when the weather turns warm. To the extent that the insulation keeps your tools warm, it will decrease condensation. To the extent that the insulation keeps you tool cold, it will increase condensation.
Dehumidifiers are great in hot weather. However, they don't work as well (or at all) when the room air is colder.
I have well insulated and generally unheated attached garages at my homes. I haven't noticed any water raining from the ceilings, but water does condense on cast iron tools and cause some rust issues--especially when the temperatures rise from freezing to warm outside.
If you heat your barn sufficiently, there won't be any cold surfaces to condense the water. If you could completely seal your barn, the warm moist air couldn't enter and condense on your cold surfaces.
Air movement and/or ventilation will help to evaporate the condensed water as it forms, and will speed the process of warming the colder surfaces (which will reduce the condensation.)
Adding insulation without adding heat and/or ventilation is a mixed bag. We tend to think of insulation as keeping the barn from cooling down when the weather turns cold. It will also keep the barn from warming up when the weather turns warm. To the extent that the insulation keeps your tools warm, it will decrease condensation. To the extent that the insulation keeps you tool cold, it will increase condensation.
Dehumidifiers are great in hot weather. However, they don't work as well (or at all) when the room air is colder.
I have well insulated and generally unheated attached garages at my homes. I haven't noticed any water raining from the ceilings, but water does condense on cast iron tools and cause some rust issues--especially when the temperatures rise from freezing to warm outside.
Sometimes I read posts here and think I'm back in school 
in a good way. That was all very helpful. I think in my situation the insulation will help. I do not hear my barn unless working in it in sub 50 degree temps, which is most of the winter. But I don't hear overnight. I plan to add a wood burner sometime this year for that. I do not plan to insulate the roof and I don't have a ceiling. I considered some sort of thin ceiling to keep the water from raining down if that happens but then it seems the ceiling would get saturated at some point.
in a good way. That was all very helpful. I think in my situation the insulation will help. I do not hear my barn unless working in it in sub 50 degree temps, which is most of the winter. But I don't hear overnight. I plan to add a wood burner sometime this year for that. I do not plan to insulate the roof and I don't have a ceiling. I considered some sort of thin ceiling to keep the water from raining down if that happens but then it seems the ceiling would get saturated at some point.Richard Cranium
Well-known member
Burning propane produces a lot of moisture inside a shop.
matt_i
Well-known member
I read above "it's missing a piece of gable trim I need to put up"
That says to me the building is not sealed (relatively speaking) and you have significant communication with the outside ambient. To keep condensation off tools you have to build a "microclimate" which is separated from outside to avoid the large positive relative humidity swings that love cold metal surfaces.
As mentioned above, using an unvented heater is a huge source of humidity.
Ceiling fans blowing on low speed 24x7 is one way to keep the humidity entrained in the air and help mitigate condensation. Actively removing it via a dehumidifier is both more effective and more expensive in terms of electricity used.
Sealing the building will help a lot. Keep the doors closed as much as possible. Spray foam the roof will prevent the roof from gathering moisture, but it doesn't completely eliminate the possibility that tools and machines could be affected if the other points aren't in play.
For example, consider the extreme case of building an open shelter with a metal roof. If you spray foam the roof it will keep the roof from raining down, but it does nothing to keep tools and machines stored under it from gathering moisture from the ambient.
That says to me the building is not sealed (relatively speaking) and you have significant communication with the outside ambient. To keep condensation off tools you have to build a "microclimate" which is separated from outside to avoid the large positive relative humidity swings that love cold metal surfaces.
As mentioned above, using an unvented heater is a huge source of humidity.
Ceiling fans blowing on low speed 24x7 is one way to keep the humidity entrained in the air and help mitigate condensation. Actively removing it via a dehumidifier is both more effective and more expensive in terms of electricity used.
Sealing the building will help a lot. Keep the doors closed as much as possible. Spray foam the roof will prevent the roof from gathering moisture, but it doesn't completely eliminate the possibility that tools and machines could be affected if the other points aren't in play.
For example, consider the extreme case of building an open shelter with a metal roof. If you spray foam the roof it will keep the roof from raining down, but it does nothing to keep tools and machines stored under it from gathering moisture from the ambient.
600SL
Well-known member
I had the same situation in my steel building. I am fully insulated but it never rained. Whenever I got a warm spell in the middle of winter water droplets and consequently rust, would form all over my tools. A Santa fee Advance 2 solved the problem and they work in cooler garages. I thought I was going to need 2 of them but 1 seems sufficient for my 30 x 48.
Expensive but it does the job.
Expensive but it does the job.