Metal building condensation (help please)!

[Bama67]

i thought about sealing the concrete with epoxy. But figured I better let it dry out some more before I do it.

 

[Oldstuff]

Bama- I have an unheated 12 ft by 20 foot totally enclosed metal building. NO insulation of any type. It had some sweat and also in the warn weather a Mold or mildew or something started to form as a film or dusting on everything. I put in a 8 in by 16 in vent up high on each gable end to get some air moving thru it and it helped. I got to thinking about where can the air come from that is to be drawn in and then put in two 6 by 16 inch vents on opposite sides about 6 inches up from the rock floor and Eureka- no more sweat and mold or what ever it was. You must have air movement. Same principal in your attic- that is why they are vented.

Oldstuff

 

[earljr59]

I Wonder if your father in law put down a plastic barrier under your concrete slab? I am not sure about your area, around here plastic below and sealer on top of floor . As others have said ceiling fans moving some air will be an important addition. When you can afford to add even a little bit of heat later on somehow to help the fans,you will be just fine.One of my old buildings doesnt have a plastic vapor barrier under the floor,or sealer and the floor will sweat when conditions are just right. Good luck,we all hate it for you.

 

[Deere Dude]

If it were me, I would talk to the company that put your building up and see if I possibly could get in touch with others with the same type of building within a 30 mile radius. I'm sure they have the same humidity situation that you have, and went through all of this beforehand and compare notes.

I would also just drive around the countryside and ask others how their buildings are working out.
I sure would hate to rip anything apart or add something expensive without making sure it is correct beforehand. There is a lot of good advice on this forum but just picking out the correct one could be difficult.

 

[EE_Bota]

You don't by chance have a ventless gas heater in there do you?

Regardless of the answer, that is a very good question!

 

[slowzuki]

Not really, at least not in a cold climate, the attic is vented so the roof stays cold preventing the snow on top from melting and sliding down to the eaves and freezing forming ice dams.

You should not be dumping moisture into your attic, ie if you have a dry or shower fan that dumps there it should be dumped outside. Venting lets you get away with this for a while but it will mold eventually.

You must have air movement. Same principal in your attic- that is why they are vented.

Oldstuff

 

[Sutol]

I have a corugated metal roof on my garage at home and the building is prety well draught proofed with no vents.
The garage has been built for 26 years and I have a condensation problem.

the roof is about ten feet off the floor and if the sun gets on the roof after a cold night condensation drips from the metal roof quite badly.
This soon drys up if the weather is nice and is not realy a problem unless I have just painted something and left it overnight to dry.

Anyway the reason I am posting is because we have just put a corugated metal roof on a building at the farm and we are worried that it may have a condensation problem just like my garage.

The metal sheets are plastic coated but we haven't had a sunny morning yet so not sure how bad the condensation will be.

We were thinking of insulating the inside of the roof but not sure if that is nesessary , we have put vents in the gable end at the top and about two feet down so as the air will flow in and out just like the wasps will do

Any ideas ? I have read the full thread but its not quite the same problem.

 

[lilranch2001]

i thought about sealing the concrete with epoxy. But figured I better let it dry out some more before I do it.

you should not put epoxy on high moisture concrete, it will surely fail and delaminate

 

[forgeblast]

take a piece of plastic and tape it to the concrete, wait a day or two and peel off the tape, if there is condensation there you know its coming up from the floor too.

 

[EddieWalker]

take a piece of plastic and tape it to the concrete, wait a day or two and peel off the tape, if there is condensation there you know its coming up from the floor too.

New concrete takes several weeks to get to a dry point that it's dry and strong enough to work on. After a month, it's almost cured and about as dry as it's going to get.

The test you are describing has nothing to do with condensation. It is to see how much moisture is left in the concrete. They do this on TV all the time because it's a fun trick to show people watching the shows. It also shows that if you install flooring too quickly after a new pour, that there may be moisture issues.

It does not tell you if you will form condensation on your metal roof, nor is it related to what is happening on a metal roof.

Condensation - Wikipedia, the free encyclopedia

What causes condensation?

Eddie