Vapor barrier or not

[MyLilMule]

I live in NE Ohio and have a small-ish (17x34) workshop attached to the back of my garage. I have insulated the walls and ceiling with batt fiberglass insulation backed with kraft paper. However, I have not put a treatment on the ceiling. My intention is to use ribbed barn siding.

My question is, should I put a vapor barrier over the insulation before installing the ceiling? I've seen competing answers on social media (because everyone there is an expert).

But what I don't want is condensation building up between the vapor barrier and the steel ceiling, causing eventual rust issues. If I were using drywall, I'd probably say yes, since it will be on the warm side. It's the steel that has me questioning the proper course of action.

 

[rabler]

No expert, but the metal is a vapor barrier. I used it in the ceiling of my shop, no additional vapor barrier, with blown in fiberglass over the top. No problem with condensation.

 

[MyLilMule]

No expert, but the metal is a vapor barrier. I used it in the ceiling of my shop, no additional vapor barrier, with blown in fiberglass over the top. No problem with condensation.

Did you tape all the joints between the insulation? I'm thinking more about air infiltration, making sure the heat stays in the shop.

 

[extropic]

Did you tape all the joints between the insulation? I'm thinking more about air infiltration, making sure the heat stays in the shop.

Blown in insulation (not bats). Very hard to tape.

 

[MyLilMule]

Blown in insulation (not bats). Very hard to tape.

Yeah, sure, I'll blow in insulation in a 6" space. And I wasn't asking you.

 

[extropic]

Yeah, sure, I'll blow in insulation in a 6" space. And I wasn't asking you.

That's twice you missed the point. Suggest you re-read rabler's reply.

 

[MyLilMule]

That's twice you missed the point. Suggest you re-read rabler's reply.

Yup. Totally missed it. Doh! I'd blame it on my dyslexia, but I'm not dyslexic.

 

[jwmay]

I’m not sure the hobby machinist experts are going to be all that much more expert than the Facebook experts. Lol

There are hundreds of results for Google searches about vapor barrier and when to use it. Much of it written by companies in the business of doing that sort of work.

I’ve never used vapor barrier in a ceiling. I’ve done about umm 200 ceilings. They weren’t ever meant to last more than five years though. They were all destroyed before we gave the area back to the locals. They preferred mud buildings.

 

[MyLilMule]

I’m not sure the hobby machinist experts are going to be all that much more expert than the Facebook experts. Lol

Yeah, but with Fakebook, I'd have to wade through about 1,000 different answers, all of them different.

I find that the people onb HM are more dedicated than the typical rabble in FB.

I've done some Googling, but like I said, I get different answers, which is why I specified where I am located. What I do in NE Ohio is likely different than what someone else does in a different climate.

 

[Eddyde]

I'm a contractor, I wouldn't bother putting any additional vapor barrier, the metal will be enough. What is the roofing material, is there a ridge vent?