Insulating Pole Barn

[samert111]

I want to insulate my 28 x 48 RV Pole Barn and was thinking of doing the following.

For the ceiling I'm thinking of R30 Kraft faced batts in between the trusses which are on 24" centers, then installing a metal ceiling.

For the walls I was thinking of stapling in some Tyvek house wrap on the inside of the purlins between the posts as a draft barrier and then verticial studs between the posts with R19 Kraft faced batts covered with OSB to finish it off.

I've checked on sprayed on foam and blown in celulose and the cost for either is as much as the entire project (metal ceiling, framing, OSB walls, etc) using fiberglass batts.

I'm in SW Michigan and plan on heating as needed to work inside.

The only thing I'm not sure about is the Kraft faced insulation in the ceiling but it's the easiest way to insulate before putting up the metal ceiling.

Thoughts?

Steve

 

[rcozzo]

For the ceiling, here's another option. Staple vapor barrier to the bottom of the trusses, taped joints. Then install metal interior liner, screwed to the bottom of the studs. Then blow insulation in over the ceiling. I built a small door on the back wall for attic access above the ceiling to use for blowing in the insulation.

 

[samert111]

rcozzo,
So your saying a vapor barier (plastic or kraft faced fiberglass) in the ceiling is OK?

What type of blown in insulation?

I priced the celulose and it's as much as the kraft faced fiberglass plus half the metal ceiling.

 

[Donnda]

Are you going to heat this building? If so you will have to think about the same things i am with my new 24 X 48 pole building. If you use Kraft batts and it gets against the metal it will wick up the condensation off of the metal. The R value goes out the window and mold will grow in it. I have not decided what I am going to do yet but thinking about aluminum faced foam board against the gurts and then framing out 24 inch on center interior wall then going with the Kraft faced insulation.
See my post about this same thing here

http://www.garagejournal.com/forum/showthread.php?t=82497

 

[mad57]

hi if you search insulating a pole building here tons of info come s up good luck.

 

[BigMike782]

Steve,I insulated my shop close to 10yrs ago now and at the time I asked a lot of questions of builders(I worked in a lumberyard) and the answer I got was to not use Tyvek inside as it probably would not work as designed.
I can tell you all about how I did mine but there is not enough room on the internet but your welcome to see the shop sometime if your near by.

 

[samert111]

Steve,I insulated my shop close to 10yrs ago now and at the time I asked a lot of questions of builders(I worked in a lumberyard) and the answer I got was to not used Tyvek inside as it probably would not work as designed.

BigMike,
Thanks for the feedback. However, I'm not sure why the Tyvek would not work as designed on a pole building but would on a house. I realize that I wouldn't be applying it exactly the same as it would be done on a stick house but would think it would be of some benifit still to help knock down drafts coming into the building.

Maybe I wasn't real clear on how I planned to use it. Which was to cut it to fit inside the poles and staple it to the inside of poles and the purlins that the exterior sideing is fastened to. Then frame in vertical studs between the posts, then kraft faced R19 fiberglass batts between the studs then OSB to finish the inside of the walls. So from the inside out it would be:

OSB, vertical studs with R19 fiberglass, purlins, metal siding.

I suppose I could take all the siding off and put it up on the purlins then put the siding back on over it but my thought was to leave an air space between the metal siding and the Tyvek to allow drainage of any moisture that may form on the inside of the siding for any reason and the Tyvek would keep the fiberglass insulation dry.

I've since thought of installing the inside closure strips on the top and bottom of my siding to eliminate any air movement behind the siding but I'm not sure about this as they would restrict drainage of any moisture that may form on the inside of the metal siding. They make the closure strips for a reason, just not sure if its for air movement or insect and rodent control.

I spoke to the local Morton Building guys and they use nothng but fiberglass insluation in all their buildings I guess and they didn't seem to have a problem with what I proposed, but then again they do not use Tyvek.

I've looked into sprayed on foam and blown in celulose and both are more expensive and I've also read that due to the chemicals in celulose it can be corrosive to metal surfaces if it get wet or damp. So I'm leaning toward the Kraft faced fiberglass batts right now.

One poster confused me on using kraft faced batts in the ceiling for fear of condinsation forming on the top side of the metal ceiling betwen the kraft facing and wicking up into the fiberglass but I don't see how that can happen. Isn't that what the insulation is designed to prevent?

 

[BigMike782]

I have spent the last 2 hrs trying to remember why I was advised not to use Tyvek inside but I can't.
One thing I will say is any place you cut it you are loosing the air infiltration value of it so if you do use it inside you would definately want to limit cutting it to the bare minimum.
I chose to put rigid foam between the purlins(my building is OSB sheeted and vinyl sided),framed false wall sections that were set between the poles and brought flush with the poles and used R-21 fiberglass.Then I sheeted the walls with OSB.
Last year I used 200 gallons of propane to keep 1,024 sf at 55 all the time and higher when I was working.

 

[csp]

Tyvek on the inside of insulation isn't a moisture barrier. It will stop wind infiltration, but won't keep moisture from passing through into the insulation.

I don't think the OP wants it inside of the insulation, however. Between the poles won't do much as it needs to be seamless around the entire perimeter to be effective.

 

[samert111]

Tyvek on the inside of insulation isn't a moisture barrier. It will stop wind infiltration, but won't keep moisture from passing through into the insulation.

I don't think the OP wants it inside of the insulation, however. Between the poles won't do much as it needs to be seamless around the entire perimeter to be effective.

OK, my primary goal for using the Tyvek between the posts then framing and insulating was to knock down the drafts as much as possible. The metal siding has ribs the entire length that are for the most part open at the top and bottom with the exception of the J channel at the top and a trim pc at the bottom to close up the ends as much as possible to keep the mice out but is not airtight by any means.

I realize by cutting the Tyvek to fit it in between the posts will diminish its effectiveness but it would have to help some. My other reason for wanting to use the Tyvek is for its ability to allow moisture vapor to pass thru it or breathe, but also protect the insulation from any heavy water intrusion. This is directly from the DuPont website.

Maybe I’m better off using the foam closure strips at the inside top and bottom of the metal siding to close up the gaps in the ribs and forget the Tyvek altogether but this would leave the insulation exposed if there were to be a driving rain that found its way in thru the metal siding.

 

[csp]

With proper installation of the metal panels you shouldn't have any water intrusion.

I've never had water penetrate through a joint on my building. If I did I'd be pretty upset at the installation.