Pole barn questions

[109jb]

Hi All,

New member with some pole barn questions that i couldn't find all the answers to searching.

I am planning to build a pole barn in the spring that will be about 45' x 54' and have some questions about condensation control, ventilation, and insulation. The barn will be for storage and workshop and will have a concrete floor with vapor barrier under the slab. I am in Northern Illinois and will be building this barn myself. Like everyone am trying to keep cost down as much as possible without compromising the building. Eventually I want to have R-19 insulation in the walls and R-40 or better in the ceiling, but to start out the plan is to not insulate for a couple years or so. I know that no insulation at all will lead to condensation problems and that brings up my questions.

1 - If I install a condensation control blanket (CCB) between the wall girts and the steel, will I have to remove the CCB, or at least the vapor barrier part of it, when I do the final insulation? Since I would have a vapor barrier (VB) on the inside of the barn, my concern is that I would be creating a mold sandwich by having the CCB VB on the outside and the inside VB with the fiberglass insuation in-between.

2 - What if I don't do a CCB in the walls and just put a house wrap between the steel and the girts until I do the final insulating?

3 - In the roof, if I put a CCB between the steel and purlins can that one stay? I am thinking it can since the eventual insulation plan is to have a ceiling liner at the bottom chord of the trusses with R-40 blown in on top of it. There would be a large ventilated air space between that and the CCB at the top chord of the trusses so it wouldn't be the same as the walls in regard to making a mold sandwich.

4 - CCB - What kind of CCB do you guys think is best, cheapest and works, or that you have experience with. I have seen so many ways to do it that I am not sure what route to go:

Fan fold foam (Not sure if this qualifies as a VB)
Foil faced rigid foam insulation board
Foil faced bubble wrap
Foil/fiberglass/foil
Foil/polyethylene insulation/foil
fiberglass w/VB on inside only
Other?

5 - Ventilation - As I said, I want to keep the cost down as much as possible without compromising the building. As for overhangs, I don't care one way or another asthetically. No overhangs is fine with me in that regard, but I want adequate attic ventilation. Cheapest would be gable end vents with no overhangs, but if this isn't adequate for venting I can do something else. Is there a way to vent the eaves without having overhangs and vented soffits? If so I could do that and ridge vents or cupolas. Is the gap created by the raised ridges in the steel enough? If not, and the gable end vents aren't sufficient, I am not opposed to having some overhang and vented soffits. I would just like to hear opinions on this.

Thanks in advance,

John B.

 

[prd2hnt]

I have a 40x60 north of Omaha. Similar climate as you I would guess.

I put the roll blanket between the purlins and the steel on the roof. The blanket isn't foil faced but rather with a tarp like material. I don't remember what it was called. The shed has been up since '03. No condensation issues whatsoever.

I have vents on each end, north and south. 2 Cupolas and vented overhangs. These sure help in the summer.

I didn't put a vapor barrier under the slab. Bonehead move.

I now have a 27x25 shop inside the shed. R-19 in the outside walls. R-13 on the inside walls. R-19 in the ceiling. Works good for me.

No insulation in the rest of the shed.

Brian

 

[toyoguy81]

I installed the standard bubble wrap on just the underside of steel roof. It was like 100 a roll. I use 1 1/2 rolls on my pole barn. It helps with condensation but thats all it does. No R -value/ My walls are not insulated either. Ive been reading alot on here about insulating a barn, at first I was gonna do spray foam, but after reading the opinions on here and how much i would use the shop vs costs, I think Im leaning towards 1 inch foam board nailed to girts, stud out horizontally and use batt inuslation, VB, then OSB

 

[minerfarmer]

I wish I had an answer for you but I have the same question. I am in the process of having a pole barn put up. I asked the builder about warping the building with house wrap and he said he would just wrap the whole building in foil backed single bubble. I will be finishing 1/2 of the inside and insulating. He said just use unfaced and no inside vapor barrier. They should be putting the metal on next week.