metal building and moisture??

LBrown59 · Dec 18, 2004

( Not a problem. We build these buildings all around here. They are engineered by the factory. In fact for my span they called for a 5' on center. but I decreased it to 4' because I like to over-kill everything. The mfg claims they are safe to walk on as long as you step on the flats and not the ribs. But since I weight 330LBs I stay on the purlins when I have to go up there. Their 6 inch purlins are designed to span 25 ft on 5 ft centers. If I remember right, the bldgs are rated for 175+ MPH winds. I always add extra ties etc. for my own peace of mind.
I deal with a place call "Metal Mart" near Shertz, TX I think they have a web site. I'll ask next time I'm up there. )
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Very interesting-never heard of building a pole building to these specifications before.

JD3130 · Dec 18, 2004

Maybe this will help!! See Attachment. This for a barn 40 feet wide, by 100 ft long.

GerardC · Dec 18, 2004

Here's a photo of the roof inside my 28 x 40. G

JD3130 · Dec 18, 2004

I see what you mean, big difference. Thats a lot of termite food there, WOW. nice. Bet that cost a lot too. Metal was cheaper than wood here before China went nuts.

slowrev · Dec 20, 2004

I was just helping a friend put metal on his 28X40 tractor building saturday. I guess he sure over engineered it. Trusses on 16" centers and 1/6 Purlins on 2 ft centers...Still have one side of the roof to put the metal on as soon as the weather breaks, was 6 deg this morning, brrr
Ben

JD3130 · Dec 21, 2004

Oh, I don't know about that, I sure wouldn't trust my building with a load of snow on it. These are designed for this part the country. Snowed the last here in 84, I think it was.
I grew up in VA, and lived in NY. so I know about the cold and snow. It's a nice 65 degrees here today!!!

LBrown59 · Dec 22, 2004

( I was just helping a friend put metal on his 28X40 tractor building saturday. I guess he sure over engineered it. Trusses on 16" centers and 1/6 Purlins on 2 ft centers...Still have one side of the roof to put the metal on as soon as the weather breaks, was 6 deg this morning, brrr
Ben
)

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I was just helping a friend put metal on his 28X40 tractor building saturday. I guess he sure over engineered it. Trusses on 16" centers and 1/6 Purlins on 2 ft centers...Still have one side of the roof to put the metal on as soon as the weather breaks, was 6 deg this morning, brrr
Ben
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A metal roofed 40' building only needs 11 trusses.
Going to 16'' centers means 31 trusses.
The extra 20 trusses @ 30 Ea = $600 blown for nothing.
I feel 2x4 purlins 2' OC would have been better and cheeper than the 1x6.

cherokee1 · May 6, 2005

Sir:

I live just north of Houston, have a steel frame barn and lots of condensation...it is disgusting. One just doesn't have this kind of problem in an uninsulated building where I came from.

After considerable thought I convinced myself that it can be solved by only a slight amount of insulation, particularly on the roof.

The problem is this...differential temperature. One sees the problem especially when a cool front blows through after a balmy humid period. The air in the building is moisture laden, this air rises and hits the steel on the roof. The steel has cooled rapidly by the cool air on the outside of the building from either a cool breeze with the front or the fall of night. As the moisture laden air hits the cool steel the capacity of the air to hold the moisture drops quickly and the moisture falls as condensation.

Fix the differential of temperature, make it less pronounced and give the building time to equalize with the outside and the problem shoudl be solved.