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I talked to a guy yesterday who is planning on insulating the ceiling of a pole barn. The trusses are 7’6″ O.C. and there are no purlins. He’s planning on buying 16′ steel and simply screwing it to the underside of the trusses. (Running perpendicular) Then he plans to blow a foot of celulose on top of the steel.
He claims that the guys at the lumberyard he talked to said this is done all the time. I’ve never heard of it, and am awful suspicious. I don’t think the light gauge sheet metal that’s typically stocked in lumberyards is anywhere near heavy enough to span that far. The steel itself might not be so bad, but I figure the added weight of the insulation will be way too much.
Am I just being conservative, or is this really a bad idea?
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I've never heard of it either, but its not like the steel is gonna break, even though it'll sag. Are you afraid it'll tear where its bolted to the trusses?
Maybe he could put 7'6" "blocks" between the trusses, and screw the edges of the sheemetal to that.
Interesting.
*Commercial structures often have corrugated steel panels as a sub-floor with concrete poured on top, but they usually put temporary supports underneath while the concrete sets up. Don't know how it would do on its own, without the concrete for compressive strength. Boss, this is probably obvious, but did you spec the bottom chord of the truss for the extra weight of whatever they use for a ceiling and insulation?
*that 's the way i've seen it done.. just not at 7'6".. the ones we had were 4' oc... worked great..maybe he could furr the trusses with 2x4 on edge and then run his steel parallel to the truss chords.. it really depends on the bending design strength of the steel panels.
*Never seen it done in upstate NY either. "No purlins" either?, hmmm. Boss, what is this guy going to store or put in this pole barn?, if he's puttin' cows in there, he'll have a nice brown ceiling in less than a year. No cows, well then it'll be nice and cosy for the pigeons, 'coons, etc. Like Mike and the others indicate here, I'd worry about the stress on the underside of the trusses too.
*7'-6" OC, that's out if you want to put insulation on top. Will not pass code, will eventually sag, may even sag right away. 4' on center is commonly done. Once the insulation is in it's rather difficult to fix any sagging problem, do it right, do it once.
*Thomas Moen -Hadn't really thought about the screws pulling through the metal. I was more concerned with the metal sagging. (Badly) The metal is 29 gauge white metal, 3/4" rib..Mike Maines -I had nothing to do with the trusses on this building. It's a Morton brand building, and they do their own trusses. .Mike Smith -> maybe he could furr the trusses with 2x4 on edge and then run his steel parallel to the truss chords..Tried that. He doesn't want to spend the time or the money. .Bill - This is a pole barn that's used for storing and working on township road maintenance equipment. No livestock.
*No purlins w. trusses 7'6" O.C.? What is the roof made up of, that it can span 7'6" with a snow load?
*Styrofoam?
*Barry -The roof has purlins 2' O.C. The proposed ceiling won't.
*What about 24 ga.?Probably close to cost of 29ga w/ purlins, tho.
*Could he just put 2' wide fiberglass bats between the purlins? Go with low flame spread commercial bats, and he won't need to cover it
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I talked to a guy yesterday who is planning on insulating the ceiling of a pole barn. The trusses are 7'6" O.C. and there are no purlins. He's planning on buying 16' steel and simply screwing it to the underside of the trusses. (Running perpendicular) Then he plans to blow a foot of celulose on top of the steel.
He claims that the guys at the lumberyard he talked to said this is done all the time. I've never heard of it, and am awful suspicious. I don't think the light gauge sheet metal that's typically stocked in lumberyards is anywhere near heavy enough to span that far. The steel itself might not be so bad, but I figure the added weight of the insulation will be way too much.
Am I just being conservative, or is this really a bad idea?