I have done a search and I am more confused now than I was before I did the search. I am getting ready to build a 40x60 pole barn style building. The primary use will be 50% shop and 50% storage. I will eventually heat the entire area and cool the shop side. In doing a search some say put vapor barrier on outside of exterior framing before you put exterior metal panels up. And some say on top of the insulation. Couldn't I just use a 6-8 mil? To me, logic tells me to put it up between the exterior panels. That way any condensation will never touch the insulation. I found the 8x40 rolls of insulation local. I will put a 6-8 mil vapor barrier on the face of the insulation prior to putting up the wall panels. Undecided if I am going metal or OSB at this time. I'm just need to know which method is preferred. I live in southern Missouri.
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Double bubble or not?
- Thread starter Kcragun
- Start date
Rookie2
Well-known member
If you use metal ,use vapor barrier to keep wind from pushing air into the insulation (except foam). I did it and proved my point to a friend that didn't listen. He could feel the air flowing in the winter, so we removed some interior and stuffed every corner and down near the floor with more batt material.IMO
Sorry,I meant to say Tyvek not vapor barrier. To keep the wind infiltration into the insulation.
Sorry,I meant to say Tyvek not vapor barrier. To keep the wind infiltration into the insulation.
Last edited:
tfinniii
Well-known member
Use Tyvek type material under outside sheathing. If using faced insulation and staple to face of studs you should not need vapor barrier.
justinjoyal
Well-known member
Tyvek on the outside, 6-mil vapor barrier on the inside.
Rookie2
Well-known member
Would you put the Tyvek under the roof panels?
MY morton 40x60 rains inside ,you need insulation under the roof sheetmetal or they make some sore of felt lined roof sheet panels. It's on this site somewhere, i'll try to search for it.
BTW: I looked into double bubble 15-20 years ago, they have not proved to this day that it can directly replace batt or spray foam insulation. Beware !
Found it :
http://dripstop.net/
Europe naturally, I emailed them for suppliers
Last edited:
DC73
Well-known member
Forget the double bubble. Borders on snake oil. Proper application and need for a vapor retarder (vapor barriers are no longer recommended) is highly dependent on your climate. What works well in dry climates may cause issues in humid climates. Best to consult the experts. Visit BuildingScience.com and GreenBuildingAdvisor.com. Both are good sources of info for proper application of insulation and vapor retarders. The GBA site also has a Q&A forum frequented by building scientists who can give you the advice you need.
DC
DC
MagKarl
Well-known member
Unfortunately opinions are about all you're going to get. Very difficult to make educated decisions on the insulation/vapor barrier topic. Everyone's climate and usage are a little different.
I have bubble wrap on my pole barn roof, it's foil on the metal side, white on the inside. My opinion is it helps and is certainly better than bare steel, but my barn is unheated and very well ventilated.
I'd do it if you're not sure how quickly you're going to insulate and condition the space.
I have bubble wrap on my pole barn roof, it's foil on the metal side, white on the inside. My opinion is it helps and is certainly better than bare steel, but my barn is unheated and very well ventilated.
I'd do it if you're not sure how quickly you're going to insulate and condition the space.
Unfortunately opinions are about all you're going to get. Very difficult to make educated decisions on the insulation/vapor barrier topic. Everyone's climate and usage are a little different.
I have bubble wrap on my pole barn roof, it's foil on the metal side, white on the inside. My opinion is it helps and is certainly better than bare steel, but my barn is unheated and very well ventilated.
I'd do it if you're not sure how quickly you're going to insulate and condition the space.
I knew that opinions was exactly what I was going to get. I will insulate within 1 year. Mainly looking to eliminate condensation. @.13 cents. A sq. I would think it wouldn't hurt. I will also do the vent ridge and possibly the vented soffits.
Rookie2
Well-known member
I knew that opinions was exactly what I was going to get. I will insulate within 1 year. Mainly looking to eliminate condensation. @.13 cents. A sq. I would think it wouldn't hurt. I will also do the vent ridge and possibly the vented soffits.
Depends on what part of the country your in, trees, how much sun etc. ridge vent/sofit does not help, i've cut holes, i installed an exhaust fan .