Ceiling in pole barn issue

[SpiderDave]

Hi all! I have a work area in my pole barn. I want to put in a finished ceiling, but I'm not sure how entirely. The biggest factor here is for it to absorb noise from tools and be fire proof, both. This is hard to explain short so bare with me please? I'm not good at this.

I'd like to use sheet rock, but I don't know if the ceiling can handle the weight? And doing it myself with no help, that's won't be possible anyway.

I have a metal roof, under that is roll fiberglass insulation with a vinyl backing facing the interior that's sandwiched between the roofing and the joists. I'd like to fill the left over void between the 2x6's with fiberglass batting and put something over that. Then I planned on putting a layer of Rockwool insulation batts over that too. This'll help absorb noise and help shield form sparks when I'm welding and grinding. I bought the batts super dirt cheap and decided to roll with it since 4x8 panels were too expensive. I plan on using a lightweight fencing wire or even chicken wire to make a barrier that'll hold back the Rockwool. I'll be accounting for stretching and even tension along the way. Think of it like a dropped ceiling full of Rockwool batting, but snug against the ceiling with no air space. I know it sounds pretty extreme but there are reasons for putting the Rockwool up. Just trust me on that one.

If I used a 1/4" plywood, it would be expensive but I 'would' be able to screw into any area needed to accommodate the screen that holds the rockwool up as I put it in. (Might not even need a screen then.) And it would help reduce noise as well.

I'd much rather use styrofoam sheet as it's super lightweight. But I'd be limited to screwing into the studs only and that would prove more tedious, harder, take longer, but still do-able. And not as sound retardant as plywood though. I could just put up corrugated roofing and call it a day. But the noise would be terrible and it would likely sweat at some point and trail down to the wall wouldn't it? Even then, it would be noisy.

The vapor barrier under the roofing is a concern. If I put styrofoam up, that might trap moisture between them. I forgot to mention that the interior ends of the rafter cavities (ceiling) would still be open to interior of the shop. The other end is a dead end exterior wall. So I was wondering if that was enough to let moisture out? Or would plywood be light enough, if I keep it at 1/4" thick ply? If I use ply, should I not use a vapor barrier beneath it? Not sure I'm explaining it right and I couldn't get pics to load.

I had considered adding more 2 x 6 joists or even doubling them? Or every other one maybe - if I had to. I was hoping someone might have ideas to toss my way here? (Fire proof and sound retardant/absorbant)

Rafters are 2x6's, 24" on center at an 11ft span. Room will be heated on occasion. Rockwool is 2'x4' @ 3" thick.

Thanks everybody who hung in there reading all that. Heh. I couldn't make that any shorter. I really appreciate it.

 

[Radix2]

Metal is not noisy if you have cellulose on top of it, there is no tinny ringing if you hit it, sounds about like hitting drywall. Corrugations break up sound reflections better than flat materials.

Metal would be the best choice based on your needs and is best for spanning long distances, inexpensive, pre finished, and easy to install.

 

[SpiderDave]

I agree and prefer the corrugated too. But nervous going that direction to find it wasn't as effective as I'd hoped. The reason I say that is because even though my shops insulated, it rings like a drum when the radio is on. The inside will absorb it, but outside its sounds much louder than when you're next to the speaker inside. The ceiling/roof is very audio transparent also, almost acts like a diaphragm. Being up high, it broadcasts out and over. I can't always make out the words, but I can hear my neighbors talking in his yard 300ft away.
Do you think the extra fiberglass insulation and tin will be a real dramatic difference enough to go for it? It would solve a lot of problems. I did look into cellulose, being my first preference, but it's so expensive I had to check that off my list. If I left the tin exposed, I'm concerned that when I used a Dust Collector or Fume Extractor that the sudden temp drop in winter would cause even slight condensation and run to the wall. Despite the fresh air vent, I will be having to seal up corners and seams of whatever I use as not to pull the negative room pressure through the ceiling. I'm definitely not arguing here, I really appreciate your help. I'm just seeing what you think after hearing more? I've never done it before in a building that mattered. So it's all educated guess' for me. I will be putting the rockwool on the exterior walls starting at 10 feet and then up to the ceiling corners. Maybe that alone will be enough to absorb what bounces off the tin? And maybe I can forget doing the ceiling? Even then, will I be okay sandwiching the space with two vapor barriers? One end of the rafter cavity will be open to the shop, is that enough to allow moisture out?

 

[PAToyota]

I'd like to use sheet rock, but I don't know if the ceiling can handle the weight? And doing it myself with no help, that's won't be possible anyway.

You're going to want to check with the pole building manufacturer on what the trusses will support. Many of them don't factor in dead load for a ceiling.

 

[cosmo52]

I used 2 layers of 6 in fiberglass insulation and strapping across the trusses. Vapor barrier and corrugated white metal. It doesn't seem to noisy when you are using power tools or impact tools. Overall, I'm pretty satisfied with the final result

 

[Joe69]

I'm hoping to have mine insulated and skinned on the inside by next fall. I'm going with corrugated metal walls. I do quite a bit of welding, and metal walls will give me some peace of mind.

 

[SpiderDave]

Sounds like we have similar plans. I have a fume extraction arm for welding fumes and a Dust Collection system for wood and both are 2,800 cfm. Though I'll have a fresh air return vent, I do worry about possible negative pressure pulling air though the walls.

But the big two issues for me is the immediate temp drop in winter months when I turn the Exhaust system on. It'll go from heated shop to outdoor cold temps very quickly and I worry about the metal condensation. It occasionally happens to my metal stock on days with a high dew point inside the shop. My other concern is trapping moisture between ceiling cavities. Wondering if one open end of the ceiling cavity is going to be enough to allow moisture to escape?

For the walls I have fire resistant sheet rock. Cheaper and the density of the sheet rock will absorb noise for neighbors. I did put 3/8 OSB behind it as a backing. If I ever hit the wall with something, I wont end up with a hole and a fire hazard to fix. Plus it ads density and the sound absorption is seriously awesome now. I tested that sheet rock with a torch, out of curiosity. It turned black of course, but would not burn.

Careful with metal in a smaller area the reflective nature of it is reflective with your arc. Most people I've known threw a coat of grey paint or whatever they had and that took care of it. If you've ever done welding in a white building, then you know. it can also be annoying when it lights up the walls around you and your interior lens white washes out for a second - from behind. Only annoys some people, not others. Like welding outside in the sun, you get those interior reflections sometimes. Just a thought but you probably already knew that.
Taker easy!

 

[Joe69]

I welded outdoors for 20+ years, so I'm used to that. The older I get, the more light I require. I'm goin with white walls. I've worked in plenty of shops with white walls, so that doesn't bother me.

 

[SpiderDave]

Yah, some it bothers other it doesn't. Should give you lots of reflective light that way. I prefer lots of extra light for my old eyeballs too. So I get it. I usually weld under cover outside, so the suns rarely at my back. No less random, just thought worth mentioning since i'm usually asking, rather than getting to help.

Just wish someone knew if moisture would be trapped in a cathedral type shop ceiling cavity where moisture & humidity is very high. The suspended Rockwool ceiling's becoming more appealing than guessing, despite the extra effort. Not as sound absorbing or deflective, but at least it would be able to breath and be fireproof. Wishing it was as easy as walls are. If there were any attic space, I wouldn't sweat it. And I can't build a false ceiling or I would've. I've read many forums that said NOT to put a moisture barrier on a shop ceiling, to prevent ice damns between. A couple even mentioned downfalls of sandwiching studs between metal sheeting in high humidity locations. That and finding a bunch of mold is what started me on this Q. Dead load is 10lbs per square foot. Should be plenty for either direction.

 

[John in OH]

Why not use steel panels? I installed steel on my shop ceiling and totally love it. It isn't significantly noisier than sheet rock and when you install the panels you are DONE! No taping, no mudding, no sanding, no dusty mess, no painting. Check out my ceiling in my build thread linked below.