I have noticed that insulation can be a very controversial topic when it comes to Barndominiums and we definitely, unreluctantly went with the most controversial insulation: closed cell insulation.  I am not an insulation expert, but I did a lot of research, spoke to a lot of contractors and of course, leaned on my very intelligent husband.     

One of the first things that really freaked me out was stories of it “raining” in the barndominium homes due to high condensation issues and improper vapor barrier and insulation.  The bottom line is, steel is highly conductive and if you have ever seen a glass or ice tea (or other drinks) outside on your porch in the middle of summer, you know what happens when the temperature inside varies greatly from the temperature outside.   

I am lucky to have a husband that grew up in a barndominium built by his dad, before that was really a thing, and he knew we had to just ensure a good vapor barrier and good insulation.  His dad used a standard vapor barrier and roll insulation and his building continues to live on.  However, due to being energy and maintenance minded husband really wanted to go with spray foam insulation.  The cost was an initial hurdle for me particularly but in the end it is one of the best decisions I feel we made. 

Your insulation options are typically: 

Blanket insulation 

Batt insulation 

Lose fill insulation 

Rigid Board insulation 

Closed Cell Spray Foam 

Open Cell Spray Foam 

You will definitely need a vapor barrier for all types other than closed cell spray foam unless it specifically states that the vapor barrier is included.  I asked my husband about the topic regarding water being trapped behind the spray foam as I often see due to condensation and impermeable foam.  However, he said a vapor barrier isn’t really supposed to be permeable either because if it was you are risking mold, damage to sheetrock, etc.  Condensation is a risk with steel buildings, but he said he would rather an insulation that is literally stuck to the steel instead of a vapor barrier laying against it. 

We would have liked to have done a layer of closed sell for vapor barrier and then add open cell for sound control, but this was just not in the budget.  We did go with 2” on the walls and 3” on the ceiling of the entire metal building, including the shop area. While they state the R rating of 7 per inch, my husband said this was rather skewed due to the lack of heat transfer and air flow.  Mind you, this is the guy that typically wants R30 +.  In addition, unlike fiberglass and some of the other, it doesn’t settle and compress which was highly important to us.  The shop is 60’x44’ (18’ side walls with 23’ in the center) and to give you a clue of the costs that I know you are wondering, we were given quotes for the depth and square footage we have in the range of $10k-$15k.   

Overall result?  Even with a vaulted ceiling in the living room area and a pretty substantial square footage, our electric bill is very reasonable. Actually, I would say our electric bill is quite impressive because it comes up often in conversation.  Insulation wasn’t the only factor in this monthly price tag, but it was a major one.  The only issue due to our giant “cooler” of a house, is keeping humidity down a little. In the summer, we try to run the A/C enough to take care of this and the dry wood stove heat helps in the winter.  The only sign we see of any issues anywhere is mold in our toilets if we don’t scrub them often enough. The biggest bonus was the minimization of metal contraction noises.  We had a dark green metal roof on our previous house and it was so noisy in the summer!  It would “talk” all day; popping and creaking as it heated up in the day and then again when it cooled down in the evening!  The building prior to the insulation, definitely did the same thing, but once we had the insulation on, this decreased so significantly that we hardly hear a sound.  If we had the open cell, it may be even more silent, but we still have no regrets.  Hopefully this helps you make the right decisions on your house too.