How Do You Insulate a Barndominium? Options & Tips

How Do You Insulate a Barndominium
How Do You Insulate a Barndominium

Barndominiums are definitely more affordable and durable than the average home. But, being that they’re made of metal like steel, temperature, and noise control are practically non-existent naturally. That means your barndominium will need some sort of insulation.

To insulate a barndominium, use closed cell spray foam. It keeps moisture and heat out, you can add multiple layers to boost the R-value, and it fits into the gaps in your home’s frame. Alternatives include the more affordable batt insulation or the moisture-resistant foam board insulation.

Fortunately, there are plenty of options when it comes to how you insulate your barndominium. So, keep reading to learn about the most popular ways to insulate a barndominium. We’ll also go over a few extra tips for getting the best out of temperature and noise control in your steel home.

What Insulation Does (and Why Your Barndominium Needs It)

Barndominiums can be a little overwhelming when it comes to the sheer number of out-of-pocket expenditures you’ll undertake. But, insulation isn’t one of those features that you should consider as “optional” for your brand new barndominium. 

Here’s why.

The primary goal of insulation is to maintain temperature control. That means it’ll keep the heat in when the outdoor temperature drops at night or during the winter. And, it’ll keep the heat out when it’s hot, humid, and sunny if you live in the South. It’s especially useful considering steel is known to absorb heat naturally, which sends your HVAC system into overdrive.

Insulation also has a few other benefits, including:

  • Sound control (from both outside and from other rooms within the home)
  • Less condensation and, as a result, less corrosion & mold
  • Greater energy efficiency

It’s important to insulate as much of your barndominium as physically possible. That includes any gaps in the structure, such as those in the walls, ceilings, floors, attics, and crawl spaces. Keep in mind that the insulation goes in before you install the drywall.

The R-Value of Insulation

When you’re doing your insulation research, there’s one term you’ll see thrown around quite a bit: R-value. This number will describe how well a certain type of insulation resists heat transfer both in and out of your home.

R-Value Zones in the United States

In the next few sections, we’re going to go over some of the most popular insulation methods for steel structures like barndominiums. But, you may be wondering, “How do I know which R-value is best for where I live?” Well, actually, the United States is broken into “zones” based on the local climate. 

So, here are the recommended R-values for each insulated area of your barndominium. You’ll notice in the chart that they’re separated into America’s zones for greatest energy efficiency (recommended by the Department of Energy).

ZoneFloorWall (2×6)Wall (2×4)Attic

Keep your recommended R-values in mind as we go over each type of insulation.

Still have some questions about what R-value is, what it means, and how it relates to insulation? Then, check out this video that’ll likely answer any question you have:

Spray Foam Insulation

Spray foam insulation is typically made out of some sort of polymer, oftentimes polyurethane. A hired contractor will spray down the gaps, cracks, and open areas of your barndominium with what appears to be a liquid. The material that’s sprayed will rapidly expand to fill in the gaps.

There are two types of spray foam insulation: Closed-cell and open cell. Regardless of the type you choose, you will need to hire a pro to get the job done. With that said, let’s go over the key differences between these two types of spray foam insulation.

Closed Cell

Closed-cell spray foam insulation is one of the most popular types of insulation for barndominiums. The term “closed cell” means that there are absolutely no open spaces in the rigid foam once it fully expands. This closed structure keeps moisture out, prevents water retention and the resulting mold, and avoids corrosion due to leak resistance.

R-Value: 6.5 to 7.0 per inch

Note: Since closed-cell foam only expands to a mere 1” thick, it’s very easy to add multiple layers to bump up the R-value to meet zone suggestions. This is not something that you can do with most types of thick insulation.

Open Cell

Unlike closed cell spray foam insulation, the open cell variety is both flexible and soft because it’s not fully encapsulated. That means that open-cell insulation is great for sound insulation both inside and outside of your barndominium. This will be a good choice if you live near an airfield, train tracks, or a busy highway. But, it may not be the best choice for temperature control.

R-Value: 3.5 to 4.6 per inch

Batt Insulation

You may have heard of batt insulation in the past, but it was probably referred to as “blanket insulation” instead. This type of insulation is the most affordable on the market today and is likely what you picture when you hear the word “insulation.” 

Batt insulation is usually made of fiberglass or rock wool and is unrolled into the gaps of your barndominium frame. Not only is it affordable, but you can also install it yourself to cut costs, and it comes in different thicknesses.

R-Value: 4.3 per inch

Foam Board Insulation

Sometimes called rigid board insulation, Foam board insulation is made of a material like fiberglass or polyurethane. The best feature of this style of insulation is that it provides twice as much heat transfer resistance by thickness as compared to other types of insulation. It performs particularly well on high ceilings, attics, and roofs. 

Just keep in mind that it can be a little pricey and your local ordinances may require you to add extra fire-retardant materials.

R-Value: 4 to 8 per inch.

Choosing a Type of Insulation: Which Is Best for You?

Now that we’ve gone over three of the more popular styles of insulation for barndominiums, it’s time to figure out which would make the best choice for your structure. To figure that out, take a look at the chart below.

Type of InsulationProsConsR-Value (Per Inch)Cost
Cell Spray FoamCan add multiple layers, prevents moisture (closed), noise insulator (open), fits in tight spacesExpensive (need to hire a professional)3.5 to 7Very High
Batt (or Blanket)Affordable, can install it yourself, comes in different thicknesses and sizesDangerous to touch or inhale, doesn’t fit well into oddly shaped areas4.3Low
Foam Board (or Rigid Board)Great solution for unfinished walls, ceilings, and roofsNeed to add a layer of gypsum board on top in most locations4 to 8High

Be sure to weigh the pros and cons first before committing to a style of insulation. After all, it may not make sense to save money by using batt insulation if your barndominium is an unusual shape or if you live up North and need a high R-value choice.

Other Barndominium Insulation Tips

Though traditional insulation is an absolute necessity in your barndominium, you can take a few extra steps to keep your new structure properly insulated. These can keep energy bills low, temperature control consistent, and intrusive sounds at a minimum.

Here are a few tips you’ll want to think about:

  • Seal Your Windows and Doors: You might think that those tiny cracks around your windows and doors are just part of the design. But, they might be letting air in and out of your home without you even knowing it! Air sealing or caulking around your windows and doors can help cut your energy costs by up to 20% and avoid drafts.
  • Add Extra Insulation to Your Roof or Attic: Did you know that a lot of the temperature dysregulation in your barndominium comes from your roof? Be sure to follow the R-value guidelines for the attic and note that these recommendations are much higher than other areas of your home. When it comes to insulation, more is always better.
  • Use Heavy Curtains: This is a simple fix if the area you live in tends to get cold during the winter months. Heavy curtains can keep cool air from seeping in from your windows and dropping your indoor temperature. Cotton and polyester are the best materials for these types of curtains.

Keep in mind that these are not alternatives to typical insulation. They are simply suggestions to further insulate your barndominium.


Insulating a barndominium is different from insulating a home given the unique shape, materials used, and areas of the country where these homes are built. In most cases, closed-cell spray foam insulation is the best choice for keeping the indoor temperature in your barndominium under control. Regardless of the type of insulation you choose, be sure to keep a close eye on the R-value and what’s recommended for the area of the country you live in.