Pole Barn Spray Foam Insulation

A pole barn, or post-frame building, is a steel skin screwed to wood girts and purlins on posts. It goes up fast and cheap, and it sweats like any other metal building. On cool mornings, humid air meets the cold steel and water drips on hay, tack, equipment and vehicles. Closed cell foam sprayed on the inside of the skin stops it and makes the barn a lot more comfortable to work in.

What we spray

• The roof: closed cell on the underside of the roof panels, sprayed over and around the purlins. 2″ to 3″ is typical.
• The walls: closed cell on the wall panels between the girts, usually 1.5″ to 2″.
• The framing: the foam wraps around the wood girts and purlins so there are no gaps or cold strips at the framing.
• The eaves and laps: the gaps where wind, dust, wasps and birds get in are sealed in the same coat.

Barns with animals

Horses and livestock will chew foam they can reach. In stall areas we keep foam on the roof and high on the walls, or plan a cover, like a wainscot of plywood or steel liner, over the lower walls. A barn with animals also needs ventilation, because animals add a lot of moisture to the air. Sealing a barn is not the same as closing it up, and we will talk through airflow on the measure.

Hay and equipment storage

For hay storage, the goal is a roof that doesn’t drip. Closed cell on the roof panels stops condensation, so top bales stay dry. For equipment sheds and workshops, foaming the walls as well makes the space usable in summer and keeps the shop side of the barn from sweating.

Open-sided buildings

Foam can’t hold a temperature in a building with open sides, but it still stops a steel roof from dripping. If that is your problem, roof-only foam is a sensible, lower-cost job.

Pricing

Pole barns are priced by the square foot of steel we spray at a given thickness. Enter your barn’s width, length, wall height and pitch in the calculator for a range, and compare with metal buildings and barndominiums.

Pole barn questions

Can you spray foam over the wood girts and purlins?

Yes. Closed cell bonds to wood as well as steel, so we spray the panels and carry the foam over and around the framing. That leaves one continuous layer instead of insulation stuffed between boards, with no cold strips where the framing touches the steel.

Will spray foam make my barn too tight for the animals?

It can if ventilation isn’t planned. Foam stops the drafts and condensation, but animals need fresh air and their moisture needs a way out. We leave planned openings like ridge vents and doors in place, and we will talk through airflow before we spray.

Is it worth insulating a barn we only use for storage?

If the roof drips or the stored items are rusting, yes. A roof-only job with 2″ of closed cell stops the drip at a fraction of the cost of the whole building. If you plan to work in the barn or cool part of it later, foaming the walls too makes sense.