How to Insulate a Barndominium - Today's Homeowner (2024)

Barndominium style homes have become increasingly popular in recent years due to their simplicity, comfortability, and cost to build. These spartan style homes often offer large amounts of space at a very cost effective price when compared to traditional wooden frame construction. However, barndos do require the same effort to insulate, especially in regions with mild to harsh winter seasons.

Today we will investigate the reasons you may want to insulate your barndominium and the possible ways to do it.

Why Should You Insulate Your Barndominium?

Generally speaking, even if a building is not planned to be a heated space, it is a good idea to insulate the exterior walls, attic, and crawlspace. This is because well built structures tend to last a while, and may go through multiple owners in its lifetime.

Although a barn house may stay comfortable year round without insulation today, most of us are aware that we cannot predict what our climate will be like in twenty years.

Since insulation resides inside wall cavities, crawlspaces, and attics, installing it after the structure is built can cost up to four times more than installing it during initial construction. As the saying goes, it is better to have it and not need it, than to need it and not have it.

How Does Barndominium Insulation Work?

With most types of insulation, the benefit comes from air trapped inside the insulation. Air is one of the best insulators, and insulation traps pockets of air inside the material, resisting the transfer of both heat and cooling.

Benefits of barndominium insulation:

• Reduce noise. Insulation not only resists thermal transfer, but sound vibrations as well, reducing outside noise from entering the home.
• Some forms of insulation, such as batting and sheet foam, provide not just insulative value but a vapor barrier as well. As many barndominiums are constructed from metal, a vapor barrier tape will help prevent potentially damaging condensation from entering the structure.
• Reducing the energy costs to heat the home.Many barndominiums often have vaulted or cathedral ceilings, meaning the ceilings are not parallel to the floor. These ceiling designs usually follow an angle similar to the roof, so there is little to no attic space. As these designs increase the vertical area of the room, they allow any heat in the room to rise away from the occupants, causing the need for additional heated air to keep the occupants comfortable. This effect however, can be greatly mitigated with insulation batts, reducing the energy costs to heat the home.

Things to Keep in Mind When Insulating a Barndominium:

• Recognize local law and building requirements. Complying with local codes is extremely important, especially those concerning insulation. For example, the simple mistake of installing R13 batting in a wall cavity when R-19 is required by local code can be an expensive, but required nightmare to correct.
• Use the correct insulation for the job. The International Building Code, also called the IBC, has minimum insulation requirements, but each local jurisdiction will have precedence. The IBC will require a minimum of R-13 in 2” x 4” walls, and R-19 in 2” x 6” walls. Crawl space insulation will usually be R-11. Attics, where approximately half of the barndo heat is lost, will typically require R-38, but in northern regions, may be R-50, or higher.
• Seal as well as insulate. Reducing the transfer of heat and cooling also involves stopping air leaks and drafts from entering the home. For example, spray foam, especially the closed cell version, does a great job of sealing larger air cracks and gaps. However, sealing and insulating are not the same thing. The pros will use tape, caulk, or other sealants to first stop any air leakage before installing the appropriate insulation.

Barndominium Insulation Options

Option 1: Cellulose

Blown-in insulation is typically the easiest type to install in house barns. The insulative material is cellulose, which is a paper product. Cellulose is inexpensive, easy to use, and works better the colder it gets. Cellulose is sold in bales which are fed into a hopper and blown into attics and wall cavities.

Cost: Usually about $1.00-$2.00 per square foot

Option 2: Loose Fiberglass

Loose fiberglass insulation is also blown in using a hopper. The material is similar in price to cellulose, but has more insulating value by weight.

Cost: Usually about $1.50-$2.50 per square foot

Option 3: Sheet Foam

Sheet foam typically is available in 1”-4” thicknesses and installs quickly.

Cost:

1.50-3.50 per square foot

Option 4: Spray Foam

Spray foam is a popular choice for new construction as it is fast and effective, although it is often more expensive than other solutions. There are two types of spray foam used for insulation in barndominiums. The first is called open cell foam, which tends to expand as it cures. Closed cell foam is much more dense and can provide a vapor barrier once it is cured.

Cost: Prices vary widely depending on the type of foam used, but expect between $1.50-$5.00 per square foot on average.

Option 5: Fiberglass Batting

Fiberglass batting is another name for rolled insulation. These are the familiar paper backed rolls used for decades. Fiberglass batting can be used in virtually any application.

Cost: $1.00-$2.00 per square foot

If you are a do-it-yourselfer, insulating your barndominium is a project you can tackle in most instances.

Some products will have advantages over others, so here we will summarize the installation processes of the most common methods.

Cellulose

1. Prepare the Hopper. Cellulose comes in compacted bales, which are mixed with forced air inside a machine called a hopper. The first step is to break a bale into sections and drop them into the hopper. The hopper has tines in the bottom that chop up the bale sections, making the cellulose airborne.
2. Install Depth Sticks. Cellulose is normally installed in attics. To keep track of the thickness as it is blown in, depth sticks (which are just long paper cards) are placed evenly apart around the attic to act as a gauge.
3. Blow the Cellulose. Attached to the hopper is a long (usually 50’, or more) hose and a remote switch. This allows the person doing the blowing to stop and start the hopper as needed. Using the depth sticks as a gauge, the insulation is then piled evenly to the desired depth.

Loose Fiberglass

1. Prepare the Hopper. Loose fiberglass comes in compacted bales as well, which are again mixed with forced air inside a hopper. The first step is to break a bale into sections and drop them into the hopper. As before, the hopper has tines in the bottom that chop up the bale sections, making the loose fiberglass airborne.
2. Install Depth Sticks. Loose fiberglass is normally installed in attics, (although it is possible to blow it into wall cavities if the wall covering is already installed). To keep track of the thickness as it is blown in, just as with cellulose, depth sticks are placed evenly apart around the attic to act as a gauge. If attempting to blow the loose fiberglass into a wall void, an opening
3. Blow the Loose Fiberglass. Attached to the hopper is a long (usually 50’, or more) hose and a remote switch. This allows the person doing the blowing to stop and start the hopper as needed. Using the depth sticks as a gauge, the insulation is then piled evenly to the desired depth. Loose fiberglass is considerably lighter than cellulose, so refilling the hopper is typically needed less frequently.

Sheet Foam

1. Measure and Cut the Sheets. Sheet foam is very simple to install, requiring just a few tools. Each sheet will usually cover 32 square feet. So, for example, if you are insulating 1000 square feet, 1000/32= about 32 sheets.
2. Attach the Sheets. Sheet foam insulation is often installed using staples, adhesive, button cap nails, or even tape. Simply line the sheets up with each other and secure them using whichever connection method suits your type of foam sheet. Even if the sheets are secured with a mechanical fastener like a staple, it is a great idea to place insulating tape across every seam to resist air flow.

Spray Foam

Although spray foam is not particularly complicated to install, this job is best left to professionals. Whether using open cell or closed cell foam, the machinery and chemicals can be dangerous without specialized training.

Open cell foam is much more flexible when cured, and is sprayed into the cavity using a machine similar to a paint sprayer. Open cell foam is allowed to expand, and then another tool (often a heated, stiff wire) melts away any excess. Closed cell foam is installed similarly, but since the closed cell foam is much more dense and does not expand very much, the second step of trimming is not usually required.

Fiberglass Batts

1. Unpack the Rolls. Fiberglass batting is also sold in bales, and some versions are even precut to fit standard wall heights, such as 96” (8’) or 108” (9’). This makes installing the batting very fast, especially with two or more people.

Pro Tip. The more air that is trapped in the batting the better. Professionals will “fluff” the batts by shaking them, allowing additional air into the batting.

2. Hang the Batts. Batts are usually installed with a simple stapler, but any number of methods will work. The batts have a fiberglass side and a vapor barrier (paper) side. The vapor barrier always faces the heated area, so in a barndominium the paper will face towards the installer. Each batt contains a small flap along both edges, which is unfolded onto the surface. In most cases, the surface will be a stud, rafter, or floor joist, so staples, button cap nails, or even insulative tape can be used to secure the batt in place.

Save Money In the Long Run and Insulate

As mentioned previously, even if a barndominium doesn’t require insulation today, that doesn’t mean it won’t be needed in the future. As barndominiums are often large and built from metal, heating and cooling one can be a challenge. Whether you are remodeling a barndominium, or building one from scratch, installing appropriate insulation might be the smartest decision you can make.