DEAR POLE BARN GURU: I have a few questions that you might be able to easily answer.
I have a metal pole building wood framed. Most of it has the standard Condensation/insulation blanket in it however some of it got damaged by mice and had to be ripped out. We are now trying to finish that area of the building to use as an office, Heated but NO A/C.
To make this a little more complicated the room is already pre-framed out to add extra insulation, this framing is now blocking any good access to the beams and girts that are structural (I have pictures but don’t know how to attach).
When talking to insulation contractors I have gotten mixed and conflicting information, I am not sure how much they know about insulating metal buildings.
How to insulate?
1. Can I use Fiberglass batts then cover with a vapor barrier and sheetrock? (The wood framing would be in the fiberglass batts) If I can… do I leave space between the fiber glass and the metal or do I want the insulation to be in contact with the metal and fill the wall as much as possible? (One insulation guy said to PACK it as full as possible with NO air gaps)
2. If the Fiberglass will not work properly installed this way, (condensation problems?) would I want to use 2″ closed cell Spray foam? Would the spray foam cause any damage or issues with the metal siding?
3. Should I do this a totally different way than I have asked?
4. Is there any issue to adding Fiberglass bats insulation between the purlins, in effect creating a hot roof. KITSAP KELSEY
DEAR KELSEY: You’ve made some good progress getting everything stripped down to the point you are at.
One wall at a time, I would remove the wall steel and install a quality housewrap. Make sure to leave enough to tightly cover around corners. You may be surprised at how quickly this can be done and the siding reinstalled. It is a good idea to use larger diameter/larger diameter screws to reattach.
Rather than batt insulation, install BIBS insulation. It will completely fill any voids and give a higher R value than batts.
Packing batt insulation in as tightly as possible would severely reduce the R value of the batts. Fiberglass batt insulation is effective only when not compressed – it is the dead air trapped within the fibers which gives the R value, not the fiberglass itself.
Placing batts between the roof purlins is not a good idea. The Code requires insulation batts in vaulted ceilings to have continuous air flow (ventilation) above the batts. Even if say 3-1/2” insulation was placed between them, the dead air above the fiberglass would be trapped between the purlins, taking away any possible airflow (not to mention having to also have sufficient ventilation at the eaves and the ridge). It would also create an airspace trapped between two vapor barriers, the condensation control blanket insulation between the purlins and the roof steel, as well as the facing of the batts.
DEAR POLE BARN GURU: I am planning to build a pole barn. I want to build it on the side of a hill with one side built into the hill. I would like to build into the hill to a depth resulting with about a 5 ft earthbag wall with crusher run limestone in the bags. A french drain would be put on the outside with some crushed rock to relieve hydraulic pressure. I would like some ideas on how to interface the poles to the earthbag partial wall. Would buttresses be needed? I can cut some red oak lumber on my portable sawmill for the sill on top of the earthbags or do a concrete beam. If the poles are 6”, and are set in the center of the bag, how do I get the siding to shed water on the outside of the bags. I know I will need to put girts on the poles for siding but they typically aren’t more than 2x4s. Looking for ideas. EARTHBAG
DEAR EARTHBAG: Post frame buildings, are by their very nature probably the easiest building for an individual to construct on their own. My first thought is why take something so simple, and make it more difficult than it has to be? Not to mention the many additional costs you have outlined.
Rather than trying to incorporate the earthbags into the building itself, why not just build an independent retaining wall away from the building? This would eliminate so many potential issues and would make the pole building construction easy, as it should be.