Condensation problem

[sros990]

I have a metal clad pole building, rigid insulation in roof and walls, and a gravel floor. There is so much condensation in the building that you can see water drip from the roof.

What is the best way to eliminate or reducce the condensation?

Thanks,

Steve

 

[Dmace]

Usually there is a vapor barrier between the insulation and the metal roofing/siding. If not than you should be able to pick up some 8 mil or thicker poly and cover all the rigid insulation. This is the same stuff that you use to cover unfaced insulation in ceilings.
It is just that, a "Vapor Barrier" so it should take care of any condensation. I have never had a metal insulated building, but this is the way I would handle it, there may be better ways.

 

[Glenn9643]

My shop is built on a concrete slab, metal roof, and insulated well. I put a 6mil poly vapor barrier beneath the slab. Zero condensation from the roof with that portion of the building.
I have a 18' x40' dropshed across the front, 20'x40' across the back, and 24'x24' dropsheds at each end. When the humidity is high it's almost like sprinkling rain beneath these dropsheds. I think this problem is created by the open air circulation beneath the metal roof for the sheds bringing moisture laden air to create the condensation on the metal.
In your case the moisture is probably coming from the soil beneath your floor. You might try scraping it back and putting down a vapor barrier, then put your gravel back over it.

 

[Highbeam]

We have many steel pole barns in this area where it rains inside from the roof. The moisture comes from the air and condednses on the cold metal just like a coke can fresh out of the fridge.

As long as you have air exposure and cold metal you will have condensation. The ambient outside air here sits in the 90% humidy range.

What folks do is prevent the cold metal from contacting the air by use of insulation that also seals with a vapor barrier. No exposed metal, no raining roof.

 

[1948berg]

In my sawmill house i stretched old (Light) tarpaulin over the rafters before putting up the corrugated iron roof. It works fine, the layer of air between the tin roof and the tarpaulin prevents the humidity from condencing, never one drop of water inside the building.
You could brobably insolate the inside of the roof with a very thin layer af any insolation, to prevent the humidity from condensing on the cold, hard surface of your ceiling.

 

[DirtRodder]

I have a question that someone may be able to answer. In my pole barn I have areas of smooth concrete floor and areas of very rough broom textured concrete floor. Only the smooth floor sweats, why?

 

[Highbeam]

Could be a couple of things. Vapor barrier under the dry side, free draining gravel under the dry side, concrete with a permeability modifier added. Even thicker concrete on the dry side. The finish should have nothing to do with it except the smooth surface will make the sweat more visible.

 

[1948berg]

Surface! The broom textured part has a much bigger surface, which enables the surface to pick up heat from the room, so the humid air wont condence against it.

 

[hilld]

So how do you stop the sweating?

 

[1948berg]

I think you have to cover the floor with something carpet like. or seal the building better so the humid outside air dont get that much access.

 

[Highbeam]

My wife's been asking me that for years.....

Good point about the surface area. The broom finish adds a bunch more area from which the water in the slab can evaporate.

Water is good in concrete, as long as it's wet it is getting stronger. I've never had a problem with too much indoor sweat on a slab. Reducing the water introduced to the barn by vehicles should help. Ventilating the air to the outside should help move the wet air out.

 

[DirtRodder]

Just as a point of interest. The floor was all poured over a surface that was prepared the same, same concrete, pored the same day, in fact the two surface textures are in the same 40x44ft. building. There are no rooms or other dividers in the area that is concreted, two areas are smooth for the shop surfaces and the textured area runs down the center and is for pulling in vehicles for maintenance.
I guess it is what it is.

 

[RON W]

I have a30x40 metal barn and oilfield pipe and it sweats after a good frost and i built a house in it with wood framing and sheetrock and has central heat and air i didnt insulate the metal barn so what do i do to stop it from sweating please help thanks ron and on the roof of the barn house inside it is insulated and i guess the heat from the house makes it worst what can i do to fix this please help

 

[Diamondpilot]

This is a big problem in my area. That is why I built my barn with OSB sheathing covered with regular 3 tab shingles and vinyl siding.. What you will have to do now is spend some $$$$ and have 1" of blown foam insulation put on the underside of the roof. 2 or 3 guys on my road had the same issue as you. The insulation is like what you buy at the hardware and expands 3X.

Chris

 

[Steve C]

I have a metal clad pole building, rigid insulation in roof and walls, and a gravel floor. There is so much condensation in the building that you can see water drip from the roof.

What is the best way to eliminate or reducce the condensation?

Thanks,

Steve

you need to put a vapor barrier on the floor, it will eliminate 99% of the moisture. The ground is a never ending source of water vapor. You will never be able to dry it out without preventing the influx of water vapor.

 

[Diamondpilot]

you need to put a vapor barrier on the floor, it will eliminate 99% of the moisture. The ground is a never ending source of water vapor. You will never be able to dry it out without preventing the influx of water vapor.

This is true. I assumed it had a slab floor with plastic under it but that is not always the case.

Chris