Insulating an old pole barn

[imagineer]

I’m thinking of finally insulating my pole barn and have a few questions…

It’s an old, drafty, single-story structure, 24’ x 36’, T-111 sided, asphalt shingle roof, concrete floor, an 8’ sliding door and a 4’ man door, 3 windows. I have a Vogelzang boxwood stove in the corner for heat. The barn is not sealed well at all. When it’s high humidity outside, it’s the same inside. There are eave vents at each end which I cover in the winter (to try and hold in any heat).

I use the barn for various projects, woodworking, welding, fixing cars and motorcycles, etc. In the summer the eave vents and windows are open, but it still gets really hot in there. In the winter, with the vents closed and using the wood stove, I can bring the temperature up to 10-15 degrees above outside temp.

My thought is to start with insulating the underside of the roof, then work my way around the perimeter walls, insulating as time and ambition allow. I am also thinking of covering the inside of the walls with OSB after the insulation is installed.

Should I have concerns about build up of condensation above the roof insulation (there is no ridge vent)?

Is a vapor barrier required?

What would be better on the underside of the roof, fiberglass batten or Styrofoam panels?

Same question for the walls, fiberglass batten, rigid Styrofoam (or expanding foam)?

I’m in a fairly rural/agricultural area (lots of mice, moles and bugs), if I use fiberglass batten, am I providing better housing for the critters?

Are there caveats or other pitfalls I should be aware of?

 

[JPinSTL]

The answer is always spray foam, but sometimes the budget does not allow.

What are the wall heights? What spacing are your trusses on? If the trusses are 5ft or less and you can deal with the ceiling height being at the bottom chord of the trusses, then running 5 rib metal roofing or corrugated barn tin perpendicular to your trusses and then blowing in cellulose will be the cheapest and easiest option.

If the trusses are spaced further than 5ft the metal will not support itself and you will need to frame structure to support it. At that point the bottom truss chord is not designed to support that additional weight. Then you'd be looking at vinyl faced "blanket" insulation at the roof level.

I did the 6in quilted blanket with radiant barrier retrofit version in my pole barn. My trusses were spaced 10ft apart. I used screws with fender washers and suspended it about every 18in from the roof purlins. The greatest benefit is in the Summer. The shop never gets over ambient temp whereas prior it was an oven. I've got a wood furnace and in the Winter I eventually can get it up about 25 to 30º over ambient but my walls/doors are not insulated yet.

 

[imagineer]

The answer is always spray foam, but sometimes the budget does not allow.

What are the wall heights? What spacing are your trusses on? If the trusses are 5ft or less and you can deal with the ceiling height being at the bottom chord of the trusses, then running 5 rib metal roofing or corrugated barn tin perpendicular to your trusses and then blowing in cellulose will be the cheapest and easiest option.

If the trusses are spaced further than 5ft the metal will not support itself and you will need to frame structure to support it. At that point the bottom truss chord is not designed to support that additional weight. Then you'd be looking at vinyl faced "blanket" insulation at the roof level.

I did the 6in quilted blanket with radiant barrier retrofit version in my pole barn. My trusses were spaced 10ft apart. I used screws with fender washers and suspended it about every 18in from the roof purlins. The greatest benefit is in the Summer. The shop never gets over ambient temp whereas prior it was an oven. I've got a wood furnace and in the Winter I eventually can get it up about 25 to 30º over ambient but my walls/doors are not insulated yet.

Wall heights are about 8'-6"
Trusses are 24" O.C.
I use the space between and above the trusses for storage, so creating a ceiling isn't really an option.
So far, research indicates that fiberglass is the least cost solution. I've also found where rafter vents are strongly recommended to manage condensation.

** I should add that the roof is not in the best shape, but isn't leaking, so any insulation method I choose, I'll want the option of re-using the insulation materials should I replace the roof and sheathing.

 

[dcg9381]

I complete agree. Even if you could just shoot the roof deck and handle the barn sides via roll insulation (or cellulose) and traditional framing.