Insulating room in pole building

[Lew22]

I just had a pole building built with 1” hemlock board siding, and now I am starting the interior work.

I am putting in a 12x16 room on top of the uninsulated concrete slab. One end of the room will sit against the posts on an exterior wall. I don’t intend to keep the room “warm” but need to be able to keep it above freezing, so I don’t plan to insulate over the slab. The interior walls will be pine tongue and groove.

How / what layers should I use to construct these walls? I have some polyiso foam board leftover from another project. Can I use that as sheathing instead of OSB, then put shiplap over top on the outside? Should I be using only the board insulation or fiberglass batts also? What type of vapor barrier do I need?

 

[Jacko264]

I think one of the. Questions will be where in the world are you that will be important to the answer

 

[BobnCO]

Yes Polyisi is fine for sheeting before T&G. Sounds like a good plan for a paint etc store room. Might even put your compressor in there for a win win!

 

[Lew22]

I think one of the. Questions will be where in the world are you that will be important to the answer

Ha, good point! Pennsylvania

 

[Lew22]

Yes Polyisi is fine for sheeting before T&G. Sounds like a good plan for a paint etc store room. Might even put your compressor in there for a win win!

Exactly! That is exactly the kind of thing I plan to use it for. The rest of the building has big doors that open and will be covered from rain, snow, etc but not suitable for storage of anything that needs to stay clear of dirt or can’t freeze.

So is this how you’d recommend I do it (outside to inside)?

hemlock board siding or shiplap —> polyiso 1.5” sheeting with taped seams —> 2x4 framing with fiberglass batts of R13 —> 3/4” pine tongue and groove

Do I need to put a layer of house wrap somewhere there?

 

[BobnCO]

I don't do the house wrap in these situations as you’re not likely to have moisture issues with your use. The poly iso taped will seal the room.. just don’t heat with open propane, “it’s a wet heat”!

 

[Firebrick43]

Exactly! That is exactly the kind of thing I plan to use it for. The rest of the building has big doors that open and will be covered from rain, snow, etc but not suitable for storage of anything that needs to stay clear of dirt or can’t freeze.

So is this how you’d recommend I do it (outside to inside)?

hemlock board siding or shiplap —> polyiso 1.5” sheeting with taped seams —> 2x4 framing with fiberglass batts of R13 —> 3/4” pine tongue and groove

Do I need to put a layer of house wrap somewhere there?

That is correct. The polyiso should be to the outside so the place where the dew point happens is in the middle of the foam and therefore inconsequential.

House wrap is not needed with a layer of polyiso that is taped as it’s even more effective as an air barrier.

 

[Hank11]

Might think about some sort of rain screen on top of the foam panels. I think it would help your shiplap exterior boards last longer.

 

[Firebrick43]

You can use polyiso foam board as sheathing, add fiberglass batts for insulation, and include a proper vapor barrier for moisture control.

Poly iso has foil faces and if taped is a vapor barrier/retarder.

It is never a good idea to have a vapor barrier on both sides of a wall to trap moisture and not allow drying.

 

[NUTTSGT]

Poly iso has foil faces and if taped is a vapor barrier/retarder.

It is never a good idea to have a vapor barrier on both sides of a wall to trap moisture and not allow drying.

I'm going to guess the one you quoted is a new user/spammer. Typical to make a few posts and come back to edit it with a link a few days later.