Ceiling vapor barrier behind metal ceiling?

[Fastback]

So I am getting ready to insulate my ceiling (R-30 wherever I can) and I am still unclear if I should use craft faced or non-faced with plastic VB added or just the non-faced and no VB? My ceiling will most likely be metal and the construction is 24" OC wood studs. I have heard about condensation being a possible issue and am unclear on how to proceed?

 

[jklingel]

The interior lid lining will be metal? Interesting. Anything above it is going to get wet from air leakage, unless you figure out how to air seal. (Air carries water; very little diffuses through.) Poly vapor barriers are not recommended unless you are severely cold. Can you sheet rock instead, as much fun as it is overhead, using the airtight drywall approach, then blow in cellulose? FG batts open like in an attic are the worst insulation on earth. A compromise is to use them, the blow cellulose several inches thick over top; that helps seal them. FG passes air a lot, which is why they use it for filters. Search around here, too. j

 

[brownbagg]

ceiling vapor barriers are not good idea. a lot of people stop doing is, moisture rise and have no where to go but set on the vapor barrier and rot out the dry wall ceiling, in your case it be the tin rusting out. no why anybody would want a tin ceiling, it be like in a snare drum anytime you work in the garage

 

[PurdueSD]

Yeah ummm, not sure why anybody would want one...

No noise problems or vapor barmier for me. My shop is heated all winter with an unheated attic above. Faced R30 above the steel...No condensation issues. Looks way better than drywall, goes up in record time and reflects light and the occasional 2x4 bouncing off of it without a mark.

 

[jwith68]

Yeah ummm, not sure why anybody would want one...

No noise problems or vapor barmier for me. My shop is heated all winter with an unheated attic above. Faced R30 above the steel...No condensation issues. Looks way better than drywall, goes up in record time and reflects light and the occasional 2x4 bouncing off of it without a mark.

What Purdue SD just said...

Only difference is mine is R30 blown fiberglass. In there for 6 years as of last month, and no issues at all. Would not do a ceiling in a working shop out of anything else.

 

[PCO6]

Yeah ummm, not sure why anybody would want one...

No noise problems or vapor barmier for me. My shop is heated all winter with an unheated attic above. Faced R30 above the steel...No condensation issues. Looks way better than drywall, goes up in record time and reflects light and the occasional 2x4 bouncing off of it without a mark.

I'm with you on all counts. I am very happy with my aluminum ceiling. I did install a vapour barrier though. I have had no condensation problems. I used strapping which provides a 3/4" air gap and maybe that helps.

 

[HDNewf]

Hey Fastback, HDNewf from the Home Depot out of Chicago here.

+1 PurdueSD.

As PurdueSD mentioned, normal construction is to use “Kraft” faced insulation, face side down. This facing is not an impermeable moisture barrier, but slows transmission significantly. Unless you plan to install a car wash business in your garage, condensation just should not be a problem.

HDNewf

 

[rcozzo]

Steel ceiling also here, with R38 cellulose blown in over a vapor barrier. No moisture issues. I heat it year round with ceiling fans running. I do not have steel siding/roof. OSB + vinyl/asphalt shingles. My attic is ventilated just like a house with soffit and ridge vents.

 

[kool55]

I have the same metal ceiling in my 42x75 shop. It has the blown in insulation without a vapor barrier. Been up since 01 and I have no moisture issues. For me, a metal ceiling is the way to go. Even lined my 36x60 horse barn cathedral ceiling with it. Easy to clean and bright.

 

[Mike007]

I have a metal ceiling with R30 bats. No condensation. Another nice thing about a metal ceiling, it weighs 1/2 of what 1/2" sheetrock weighs. It was a concern for my garage because the trusses are 4' apart.

 

[brownbagg]

I dont see how you can afford it, I price some last week and it was 22 dollars for a piece 3 foot by 20. that be over 500 dollar in just material to do mine

 

[Fastback]

Sweet! R-30 and a tin top it is! Thanks for the insight guys!

Hey Brownbag, check Menards for the really thin stuff, my 720 SF will be about $400 + any edge materials. I dont think 5/8 sheetrock finished out is much less.

 

[Mike007]

I dont see how you can afford it, I price some last week and it was 22 dollars for a piece 3 foot by 20. that be over 500 dollar in just material to do mine

Mine was a little over $500 for just the material. But I looked at it this way. There is no way I'm sheet-rocking, so I'd have to pay someone plus pay for the rock. And I'm not painting either. So for me it's was probably cheaper.

 

[PCO6]

Mine was a little over $500 for just the material. But I looked at it this way. There is no way I'm sheet-rocking, so I'd have to pay someone plus pay for the rock. And I'm not painting either. So for me it's was probably cheaper.

That's the way I saw it regarding my metal ceiling plus I was able to do it quickly and by myself.

 

[haugy]

Are any of you having issues with the blown in seeping out of the seems? That's why I was told to put up a vapor barrier. To keep the insulation up there. Otherwise dust gets everywhere when it's windy.

 

[jwith68]

Are any of you having issues with the blown in seeping out of the seems? That's why I was told to put up a vapor barrier. To keep the insulation up there. Otherwise dust gets everywhere when it's windy.

If you are going to use blown cellulose, I can see that being a potential issue. With blown in fiberglass, it has not been an issue at all - the fiberglass tends to stay in small, discreet "tufts" (for lack of a better term) that won't make it through any reasonably narrow opening.