I just built a pole barn, it 24" by 40" with 10' walls and a 4/12 roof.  I want to heat it with radiant floor heat.  I'm trying to figure the best way to insulate it.  My first choice is closed cell spray foam, but the budget will only allow 2".  I want the structure to be as tight as possible and plan to use a HRV to control air quality.  Am I on the right track or does anybody know a better way?  The building is located in Central Maryland.  Thanks,

What is the building to be used for?

The building will be a metal/wood shop. It will be heated by a radiant system in the slab. Winter heating requirements would only be up to 60 deg F.

2" is probably OK for a shop, I question the neccesity for a HRV, an exhaust fan is probably better suited for fume and dust, your air infiltration will be around door and window openings, unless you provide another fresh air supply inlet near exhaust.

If you are already having trusses, purlins and girts like a traditional pole building you may want to consider 2"-3"steel SIPs that already have the roofing and siding integral with panels. saving a step and providing a clean washable interior surface

This building is kind of an experment. I'm trying to build the lowest cost ($25 to $30 per sqft), most energy effiecnt stucture I can. The goal is to get it as air tight as possible, that's why I chose the closed cell foam for insulation and air barrier and the HRV for air quality.

I looked into sips, but the cost factor ruled it out. It would be my choose for new living space. Great idea about using it for the roof. I still have a Garage to build. What kind of cost are these steel sips? I was told by a local sip builder to figure $10 sqft installed plus surface coverings for wood covered sips.

Thanks

the advantage over the wood sips is you are kiling several birds with one stone and replacing several components all at once....... insulation, vapor barrier, exterior paint, interior finish/paint, soffit, roof and wall coverings for about the same or slightly higher as wood SIPs

Posted By siteturbo on 14 Sep 2011 04:40 PM
For those of you interested, I found a forum dedicated directly to barns at www.BarnsBB.com :-)

What was the cost per square foot for that kind of structure?

I installed insulation in a similar situation a few years back. It was an auto salvage yard that used a pole barn for taking apart engines and tranys. The owner used stell siding on the inside because of the grease and oil. He ran the siding sideways from the botton to the top so he could pressure wash the walls and used a raised heel truss inside the building framework. This allowed for a balloon frame into the attic thru which we blew 8" of cellulose into the walls and on R-50 in the ceiling. If I remember right the wall area was about 5000sq ft net and the ceiling was 5000 sq ft. Three men did the whole thing in 1 day and the price knocked every other system out of the box as far as r-value and cost.