Help Fix my Condensation Problem in Pole Building

12gauge · Dec 26, 2007

Hello,

unfortunately i found this forum a day late & dollar short

i had a pole building built & pretty much everything was done wrong from what i can see. 36'ft deep, 48'ft long, 12'ft high doors & 13ft eaves. metal roofing & metal siding. The walls were built with 2x6 for ease of insulation, or so i thought.

the ceiling has a thin layer of fiberglass with a white plastic vapor barrier installed on top of the building in between the roofing & wood. on the side walls the metal siding is directly screwed into the 2x6's on 24" centers.

The concrete was poured without a vapor barrier, in floor heating was supposed to happen but due to 6 months of waiting with my money in hand. I finally had to threaten to call the sheriff & i just said pour it. didnt want to wait. Thus, i'm sure i'm getting moisture in the shop through the floor. I can put cardboard down & have a moist spot there.

I took over from here & continued to make stupid mistakes. I put R19 in the side walls & over the roof insulation already there. The walls are dripping with water now behind the insulation & I just discovered the roof is now wet on the white plastic above the R-19. (R19 was paper tar backed). i had to rent a scissor lift to even get to the roof.

of course i didnt discover this moisture problem until most of the drywall was already installed & now its finished on the side walls. No drywall on cieling.

I have a fan running full time for the last week along with propane heaters(more moisture) & its not any better. My metal doors are even dripping with condensation & so are were areas of the building that had no insulation. Because the doors & areas with no insulation are wet, i'm hoping that is a clue to someone more experienced & smarter than me. :bowdown:

options =
1. Dehumidifier (large one) (3 12 ft insulated bay doors to fight)
2. tear off all the insulation in roof, or maybe just the paper backing
3. tear off steel siding & wrap in foil bubble or plastic wrap to protect wood
4. replace all steel siding with house siding.
5. try to coat floor to reduce moisture from coming up, not sure if this is possible
6. Add lots of vents (none really now, but the sheet metal kind of is self venting except for the insulation up against it)
7. burn building down & shoot myself :lol_hitti

Sorry for the long post, but right now i wish i never even started this project. All this money spent i could have just paid to have projects done for the next 30 years instead of doing them myself in the shop.

thanks for the help,

very confused & depressed

Franz© · Dec 26, 2007

OK, breathe in and out slowly 10 times, you ain't in near as much trouble as you think.

1) where the hell are you, it makes a lot of difference.
2) shut down the propane heaters. The number 1 product of propane combustion is Co2, and right behind that is WATER VAPOR.
You are making the problem worse every minute the heaters run.
If you absolutely have to have heat, use a vented burner that sends products of combustion outside.

What to do next is largely dependant on outside temperature.

Kevin54 · Dec 26, 2007

I have a fan running full time for the last week along with propane heaters(more moisture) & its not any better. My metal doors are even dripping with condensation & so are were areas of the building that had no insulation. Because the doors & areas with no insulation are wet, i'm hoping that is a clue to someone more experienced & smarter than me.

Before I even seen Franz answer, I knew propane was one of the causes. Secondly, with a pole barn, when warm meets cold, you get condensation. If you need to heat it, and need heat for the winter, I would look at least into a wood burner if possible. At least with a wood burner, it will pull moisture out of the air instead of introducing it. Next, I would pulll all of the insulation down from the top if possible. I never did like the thin foam batts they put in a pole type building. You need air between the batts and the metal. Those thin batts do not have a lot of R value and they will pull the cold thru them alomg with the cold underneath them. As soon as warm moist air (propane) is introduced, the air rises and the metal and batts start to sweat. If you are in the cold snow area, I bet if you get it to 70 in the building, the snow is melting off of the roof. Now as far as shooting yourself.....no need. Anything can be fixed. It just may not get done as soon as you would like. I don't know where you are at, but if worse comes to worse, just shut everything down until spring if possible. At least if it is cold in there, then the moisture problem will go away until it can be properly fixed. But one thing for certain, you don't want to keep letting the moisture saturate the insulation. for one it is not good on the steel panels, and secondly, it can create black mold, and you don't want that. Also if you run a propane heater, and you run a dehumidifier, the DH won't be able to keep up, and there will still be way more than enough heat reaching the ceiling causing the same problem than the DH will ever remove.

rodnok1 · Dec 26, 2007

I agree with the others, it can be fixed. The problem you are having is you are heating the building up without it being sealed up all the way. Insulation itself will not prevent moisture build up, esp with metal. Stop using the propane heaters as Franz and Kevin54 said. I don't think I would put ionsualtion against the roof insulation just because of the condensation possibilities. I would leave it at ceiling and make sure attic area is well ventilated, with soffit vents/redige vents/gable vents(whatever you can use) it gives the moisture somewhere to go besides the insulation. I agree with what temp/hum it is outside questions/answers. It may have to wait until spring. If you have uninsulated parts you may want to seperate them for now with plastic sheeting, then de-hunidify the rest. Don't give up it can be fixed...if I gave up everytime I screwed up(or got screwed) I'd be on this board all the time...LOL

Red Green · Dec 26, 2007

I am planning on setting up some rock salt dehumidifers in the spring when I have my yearly condensation problems as decribed in this thread http://www.garagejournal.com/forum/showthread.php?t=10131&highlight=rock+salt&page=4

W-Cummins · Dec 26, 2007

To get condensation you need the vapor laden air to come into contact with a colder surface. So you must have humid air inside your building or the panels are leaking air/water vapor. If the panels were installed correctly with mastic on the roof and overlapped on the seams properly on the walls/roof, you probably are not getting the warmer moist air in that way. You did mention in your post that you have water dripping on the back side ( the panel side??) of the plastic roof vapor barrier, If that is true you may have problems with the panels or that vapor barrier is no good.

As others have said stop the direct vented heat source you running in the building as it's a SUPER source of warm moist air.

So you need to have ONE vapor barrier in the roof. Right now you have 2 and that is not a good idea. So you need to perforate one of the layers. It would be the easiest to do the kraft face, as you need to remove the kraft faced bats to poke holes in the plastic facing of the other insulation. IF you do the kraft facing you will have a vapor barrier in the center of the insulation and that will/can work ok depending on your area. My living space is insulated that way in my shop ( check out the link at the bottom for how I did it. I had to perforate the double bubble foil radiant insulation I used in the roof to prevent having 2 barriers whole shop)
I wouldn't remove the insulation that was installed in your roof there is NOTHING wrong with it and there is NO need to have an airspace under the steel if you keep the moisture away from it with a vapor barrier.

William....

bgarrett · Dec 26, 2007

here is a link to earth tubes which de-humidify air
I hope you are intelligent enough to see how they can be added to your structure without going thru the slab

http://mb-soft.com/solar/saving.html

12gauge · Dec 26, 2007

1. Just north of Seattle = Rain, Rain, & more Rain, between 40 to 50 degrees in the day & down in the low 30's at night typically.

2. I ordered a mr. heater 75K btu with the horizontal vent kit last weekend. just waiting for it.

Franz© said:
OK, breathe in and out slowly 10 times, you ain't in near as much trouble as you think.

1) where the hell are you, it makes a lot of difference.
2) shut down the propane heaters. The number 1 product of propane combustion is Co2, and right behind that is WATER VAPOR.
You are making the problem worse every minute the heaters run.
If you absolutely have to have heat, use a vented burner that sends products of combustion outside.

What to do next is largely dependant on outside temperature.

12gauge · Dec 26, 2007

this seems to be geared more towards cooling a structure. I need to heat it. However, it does sound interesting for dehumidification. But i'm not sure how it would work with the outside ground being warmer than the building & it would cause me to burn a lot of propane heating it.

bgarrett said:
here is a link to earth tubes which de-humidify air
I hope you are intelligent enough to see how they can be added to your structure without going thru the slab

http://mb-soft.com/solar/saving.html

12gauge · Dec 26, 2007

I had the condensation problem on the side walls, even before i turned on the propane tanks. I noticed the roof problems after i turned on the propane.

The insulated garage doors were also wet before the propane was turned on, all the metal trim looks like they just stepped out of a shower. I know the propane isnt helping, & it will be turned off as soon as the mud dries on the sheet rock (2 more days i hope).

I do plan to add a wood stove, looks like i need to that ASAP. i was hoping to find a free one 1st.

just to clarify, the thin insulation batts that the builder put in the building did not condensate to my knowledge until i added the additional R19 on top of it. The garage doors however, started the condensation problem badly this fall.

Kevin54 said:
Before I even seen Franz answer, I knew propane was one of the causes. Secondly, with a pole barn, when warm meets cold, you get condensation. If you need to heat it, and need heat for the winter, I would look at least into a wood burner if possible. At least with a wood burner, it will pull moisture out of the air instead of introducing it. Next, I would pulll all of the insulation down from the top if possible. I never did like the thin foam batts they put in a pole type building. You need air between the batts and the metal. Those thin batts do not have a lot of R value and they will pull the cold thru them alomg with the cold underneath them. As soon as warm moist air (propane) is introduced, the air rises and the metal and batts start to sweat. If you are in the cold snow area, I bet if you get it to 70 in the building, the snow is melting off of the roof. Now as far as shooting yourself.....no need. Anything can be fixed. It just may not get done as soon as you would like. I don't know where you are at, but if worse comes to worse, just shut everything down until spring if possible. At least if it is cold in there, then the moisture problem will go away until it can be properly fixed. But one thing for certain, you don't want to keep letting the moisture saturate the insulation. for one it is not good on the steel panels, and secondly, it can create black mold, and you don't want that. Also if you run a propane heater, and you run a dehumidifier, the DH won't be able to keep up, and there will still be way more than enough heat reaching the ceiling causing the same problem than the DH will ever remove.

Curtis M · Dec 26, 2007

Wont there be moisture coming out of the concrete slab for some time as well ?

Franz© · Dec 26, 2007

OK, your first problem is location, one of the great dew harvesting sites in North America, and you set a steel dew harvester right in the middle of it. Now you have a couple options.
1) jack the building up onto a truck and move it to Arizona. I'm figuring that's a no.
2) eliminate the sourses of harvestable dew inside th e building and minimize the amount of water available for condensation. (probably what you want to do)

You can go nuts trying to eliminate what you believe might be the sourses, or you can eliminate them one at a time and see what you gain.

Since you previously stated there is poly sleved insulation between the roof and frame, I'll ignore the roof for now. It probably isn't the problem you think it is.

Your statement that the inside of the walls and doors is sweating indicates you have a perfect dewfarm on the walls. Your location ambient humidity is acting on the condensing surface (wall) as soon as the wall falls below the dew point, and condensation is happening. You're also adding to the available suply of water inside the building every minute and you probably don't want to stop heating.

The simplest and most cost effective temporary solution would be to hang 4 or 6 mil poly 6" inside of the walls as a curtain. This will provide a trapped air space between the poly and the steel, and minimize the condensation on the steel. It will also cut your heating cost.
The poly should be as airtight of a chamber as you can make it with the outside wall. Once you have the chamber, a couple computer fans circulating outside "dry" air thru the chamber will dehydrate it quickly.
If you have a home weather station observe the difference between daytime humidity conditions and night humidity conditions.

You also need to vent the top part of the heated area to allow the humidity produced by the LP heaters to leave the building.

I see no point to hanging a curtain insode the doors, other than to prevent heat loss.

Since you already stated the floor is over well drained soil, and presuming the floor is more than 30 days old, it should not be a sourse of humidity. The difficulty in making that determination right now is you may already have saturated the floor. For those reasons, I wouldn't attempt to make any determination on the floor right now.

12gauge · Dec 26, 2007

after reading Franz's reply, I went out & bought a whether station. I have also turned off all the propane heat as the drywall mud is now dry enough & I still have the 3 fans running along with opening the window a couple inches. I can deal with no heat until i can get a dry source of heat.

It is 7:15pm current humidity is 66% inside & 53% outside. 51F inside & 34F outside.
At 10:30pm humidity is 72% inside & 76% outside, huh? (this is after turning off heaters)

W-Cummins · Dec 27, 2007

12gauge said:
after reading Franz's reply, I went out & bought a whether station. I have also turned off all the propane heat as the drywall mud is now dry enough & I still have the 3 fans running along with opening the window a couple inches. I can deal with no heat until i can get a dry source of heat.

It is 7:15pm current humidity is 66% inside & 53% outside. 51F inside & 34F outside.
At 10:30pm humidity is 72% inside & 76% outside, huh? (this is after turning off heaters)

Close the dam window!! You can't dry out all of king county :shocking:

You have to decrease the infiltration of wet air and as discussed slow down making more inside. Did they use the inside closure strips on the top and bottoms of the wall panels? Do you have door seals on the overhead doors?

William....

Franz© · Dec 27, 2007

Comon now William, he's just about got enough water in there now for a decent indoor pool.

I figure if he leaves the heat off for a day and power vents the building for about 8 hours at night he just might dry it up a little.
If he don't he will be usin a mop in there.

Jay H 237 · Dec 27, 2007

I would also make sure the building has gutters and the downspouts are directed away from the building along with the grading of the land. With the amount of rain he gets and if the water stays near the building it can wick up through the slab introducing more moisture into the building.

12gauge · Dec 27, 2007

humidity update 81% outside & 77% inside. Windows are shut now, dont think i want to pull the 81% inside.

I think i'm fighting a losing battle. How should i rethink this? new siding & false celings to insulate instead?

12gauge · Dec 27, 2007

No, I do not think there are closure strips on the top & bottom of the wall panels, but i'm not sure what they look like, or if i can see them from the outside. There is just trim of some sort.

there are seals on the bottom, but i can see light on the edges of the door closing, so there not sealed that great.

W-Cummins said:
Close the dam window!! You can't dry out all of king county

You have to decrease the infiltration of wet air and as discussed slow down making more inside. Did they use the inside closure strips on the top and bottoms of the wall panels? Do you have door seals on the overhead doors?

William....

Franz© · Dec 27, 2007

Just start ventilating again when the humidity outside drops below the humidity inside. If you can draw air across the building you'll win eventually.

W-Cummins · Dec 28, 2007

Franz© said:
Just start ventilating again when the humidity outside drops below the humidity inside.

That probably will not happen again until June :bounce:

If he gets the vented heater up and running it will lower the humidity in there nicely and if he can close up the leaks, more humid air will not get back in. I would look into some top and side seals for the over head doors. I'm thinking about using the sealeze brush seals they look interesting but they are rather $$

William....

Franz© · Dec 28, 2007

I'm thinking he needs to go with the first option, put the building on a truck and move it to Arizona.

The problem remains that the building cannot be easily dehydrated by sealing and heating alone. That even if acheivable would just create a negitive pressure chamber.
While I have no inclination to check databases, I have a strong hunch the ambient outdoor humidity drops at night, even in King County.

Air exchanges seem the most cost effective in my mind. Heating the inside of the chamber will retain the current volume of water and only slightly lower the relitive humidity. The only options I see are air exchange and or condensing the humidity into liquid for disposal.

12gauge · Dec 28, 2007

i bought a 75pint dehumidifier last night at lowes. its a whirpool, dont know how well it works, but it pulled a good amount of water out last night. However, humidity was still about 77 in the building & 85 outside this morning.

there is 5 inches of snow on the ground (i'm actually in snohomish county just north of king)

anojones · Dec 28, 2007

Not to hijack this thread, but I'm about to enter into a similar situation and have a question that may help the original poster. We have a new metal sided pole barn with a soon to be completed finished area that will be heated and cooled year round. I have used residential type kraft faced fiberglass batts from a big box store. I have R38 in the 12' ceiling at the bottom of the trusses (there is the standard vinyl stuff between the purlins and the metal roof- but lots of attic space between the insulated areas). My concern is the kraft faced R21 in the walls- they are placed horizontally between the girts and face stapled with the kraft paper facing into the room with the unfaced side touching the metal siding- it fills the whole 6" cavity. I haven't heated the place yet, but plan on drywall soon and will then be heating the space and am concerned that I will have the same problems as the original poster- the heated air inside will allow vapor through the insulation which will condense on the metal. Would adding a 4mil poly over the existing (and in contact with) the kraft vapor barrier help- or would it just end up trapping moisture between the poly and metal? Is the kraft vapor retarder enough? I don't have the same moisture problems, I'm in Washington but on the dry side of the state and will be heating/cooling with a thru the wall heat pump (PTAC unit). Perhaps a less permeble vapor barrier would help the original poster as well?

Franz© · Dec 28, 2007

Steel wall/ poly/fiberglass/kraft/interior wall will serve you best if you INSIST on using fiberglass.

Condensatios is going to happen on th einside of any steel wall building. Best thing you can do is minimize the hor wet air from contacting the steel and prevent the condensation from wicking into the fiberglass.

anojones · Dec 28, 2007

In retrospect, I wish I had considered other insulation options- but didn't at the time. In the configuration above- wouldn't the condensation just form on the poly near the steel wall causing the same problem? I suppose having an airspace between the metal and poly or fiberglass might help- but it's all ready installed and much more feasible to deal with the side all ready facing the room.

12gauge · Dec 28, 2007

you will have the same problem as me with the R-21 Kraft in the wall.

after much drinking & thought, i am thinking of taking the siding off & putting a 3/4" strip(plastic or treated wood) followed by plastic liner & then the siding again. at least this way the wood & insulation wood breathe & the water could just drip down without hitting my building like it does now.

I'm also hoping Franz will answer your question below, because if i take off the siding & add poly, i think the condensation would just form on the poly as well. Because that is what it is doing on the roof m (althogh the poly on the roof as thin insulation between the metal & poly).

anojones said:
In retrospect, I wish I had considered other insulation options- but didn't at the time. In the configuration above- wouldn't the condensation just form on the poly near the steel wall causing the same problem? I suppose having an airspace between the metal and poly or fiberglass might help- but it's all ready installed and much more feasible to deal with the side all ready facing the room.

Franz© · Dec 29, 2007

Guys you're taking the condensation on the inside of the steel way too seriously.
I can show you steel buildings put up in 66 with the **** 1" fiberglass in a drycleaning bag between the skin and the frame, and they are still in good shape.

The common thread in all your situations is getting the skin on and the floor poured in warm season, and then jumping onto interior finishing when it turned cold. Then add in a water producing heater, and you naturally have a dehumidifier wall. There ain't a damn thing happening on that wall that doesn't happen with a basement dehumidifier. Cold surface + humid air = condensation.

The situation will equalize over time, and the wall won't be the condensation surface because additional water laden air won't be reaching the steel wall.

Having a poly membrane an inch back from the steel will acomplish a lot during construction, and will yield monor benefit down the line, like preventing the fiberglass from wicking, but had you installed insulation and drywall or whatever before the temperature outside dropped the condensation wouldn't be occurring now.

This might amaze yall, but we been putting up steel buildings for a lot of years, and just about every one that is put up going into winter has the same situation. My name ain't Neitermeyer and I assure you there is no need to panic.

NOW, if you want to watch a steel building skin rot, just pump the wall cavity full of celulose insulation. Even minimal condensation in that situation will cause the borax fireproofing to change to boric acid, and you can watch the skin fall off in 10 years.

If you want the best possible situation, use sprayed on foam and increase the building's structural integrity as well as having the best insulation.

ksbee · Dec 31, 2007

Hello all, I will second advise on the sprayed foam insulation. We have a metal shop building built in the early '70s with concrete floor and no vapor barrier. Shortly after construction was complete we had foam sprayed on all the walls and ceiling. The building is still completely rust free and has never sweat a drop. We keep the building at about 55 deg. in the winter with a forced air propane heater.

12gauge · Jan 10, 2008

Ksbee,

I only wish i would have done that. i would have had the roof sprayed too & not used that roll-in thin insulation junk that pole building companies use.

with 2 dehumidifiers running i am able to keep a 7 to 10% RH difference now between outside & the shop. drywall should be good & dry now too. i finally had 1 day where outside was only 40%, so i opened everything up. The doors have stayed dry since that day. & everywhere i took insulation off the cieling it has dried up. but behind the insulation, it is still really wet.

i'm going to put the insulation back up in the dry areas to see if new condensation forms or if its only old condensation that wont dry up because of the cold humid weather.

anojones · Jan 10, 2008

After this thread I added a 6 mil vapor barrier over the fiberglass insulation that is in contact with the metal siding. Hopefully this will limit moisture from reaching the metal wall, although it limits it's escape path as well (can't win). I agree, should have considered spray on insulation. I haven't had any condensation problems yet, but haven't heated yet either. I live in a less humid climate and will be heating with a thru the wall unit that will recycle the air.

Bob Burr · Nov 4, 2008

I am about to insulate my pole barn building. My building has 6 inch poles, is framed out with 6 inch wood, is wrapped on the outside, and is sided with wood on the outside. We will be insulating the walls with R-19 fiberglas with a Kraft backing placed to the inside.

My question is: after installing the insulation, should I put up a plastic (6 mil) vapor barrier before installing the inside wood paneling?

Thanks for help in advance.

kbs2244 · Nov 4, 2008

Yes.
And get a vented furnace.

Help Fix my Condensation Problem in Pole Building

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