Sweating metal building. Exhaust fan???

[BoylermanCT]

Hello BoylermanCT, I have an uninsulated corrugated iron clad woolshed. Most mornings, inside the shed it "rains" as the condensation runs down the iron and onto the purlins , then drips on the floor. The solution is to use waterproof roofing "paper" designed to stop this problem. I used the silver version so the light is reflected off the ceiling (the black version swallows light and makes things dark). So, dry shed and better lighting. I get 80" anually and a heavy dew most days.

Thanks Redman. Did some quick online research, and there is a product DripStop that is applied by the factory to the underside of the metal roof. A type of felt that supposedly absorbs the water and then evaporates the water as temps increase. Anyone use this?

Drip Stop Condensation Control - Dripstop Insulation for Metal Roofs | ABC

If you use the waterproofing paper (is it Tyvek?), do you put the paper down on the purlins and then screw the metal roof on top of it?

 

[RNeumann]

http://www.mbma.com/media/10.01.01Condensation.pdf

 

[texas42]

1inch of sprayed on closed cell foam insulation will solve your problem.

 

[Industrial Toys]

It's a major PITA. When temps warm, Everything colder in my shop sweats. Insulation won't help that. Not if you have a door open.

My Dad worked for a steel company that had an enormous, automated storage facility. They HEATED that thing all year round, even, during our hot Canadian summers, just to keep the steel above the dew point. I guess it was cheaper than air conditioning it, and since it was mostly unoccupied, it didn't matter.