Insulating a Home office/gym build inside Pole barn

[doberman21]

hey all,

I am enclosing a 500 sq/ft section in my pole barn to become a gym/home office. Since it’s the back corner of the barn, two of the four walls have 1.5 inches of spray foam. Since I’m putting drywall up, I decided to raise framing on all four sides of the room. For the interior walls, I’m planning to put batt insulation up. For the 2 exterior walls with spray foam, I was planning to leave that framing empty. The more I read the more unsure I get on whether there needs to be any additional insulation for those walls, or if it would just be overkill or cause more of a problem by trapping air between batts and spray foam. I’d imagine there is a 8 to 10 inch space between the outside of the framing and the surface of the spray foam on the wall. Thoughts on adding additional insulation here or just add drywall and call it good? Picture attached

I’ll be heating/cooling the space with a DIY Mr. cool heat pump.

Thanks all

 

[gimpyrobb]

I would insulate all the walls. I don't know if you plan on using a vapor barrier, but I wouldn't on the walls near the foam walls.

 

[doberman21]

I was not planning on using a vapor barrier. So if I run batts up the framing on top of the spray foam, there will be a gap between the foam and the batt. I’ve heard this can be a problem.

 

[Hank11]

Where is the building located?

 

[doberman21]

Where is the building located?

Northern Indiana.

 

[theoldwizard1]

For the interior walls, I’m planning to put batt insulation up. For the 2 exterior walls with spray foam, I was planning to leave that framing empty. The more I read the more unsure I get on whether there needs to be any additional insulation for those walls, or if it would just be overkill or cause more of a problem by trapping air between batts and spray foam.

If that empty space is truly SEALED (and it should be it the spray foam job was done correctly), then "dead air" is actually a good insulator ! You try just installed a vapor barrier on the inside and leaving it that way for a few weeks. Any movement would reveal how well the air was getting past the foam on the outer wall.

Segue - Believe it or not, there is an indoor ski hill somewhere in Saudi Arabia. The "insulation" is about 12' of "dead air" !

 

[nadogail]

You possibilities are Endless, just go with an appropriate amount of whatever you choose to use. Keep in mind that your space has 4 walls, a top and a bottom.

 

[doberman21]

Thanks all for you replies. I think my main concern is moisture in the walls. I’m not 100% sure the amount of spray foam is thick enough to remove the risk of condensation on the foam during the freezing months. If I put a roll of fiberglass batts up do I potentially trap moisture in the walls and have a mold outbreak on my hands 5 years down the road? Would using rockwool or faceless/faced batts make a difference here?