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How Much Does Spray Foam Insulation Cost?

spray foam insulation

How Much Does Spray Foam Insulation Cost? Blog Feature
Amanda Ringler

By: Amanda Ringler on November 7th, 2023

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Spray foam insulation has a lot of great benefits to offer for your existing home, newly built home, or pole barn, but just like everything else in life, it comes with a price tag.

Honestly, that price tag is going to be several times the cost of fiberglass or cellulose insulation, but there’s more to consider than just the numbers. If you want a premium product with premium benefits, you’ll get exactly what you’re paying for.

Let’s take a moment to discuss where spray foam insulation can be used before we dive into how much the material costs. Spray foam can be used in any open cavity in the home, including the attic, crawl space, rim joist, and exposed walls. It can also be used in new build construction, pole barns, and commercial buildings.

One of the many choices you have to make is whether you want to use open cell spray foam or closed cell spray foam for your project. Again, just like everything else, that choice also comes with a price tag, as one product is more expensive than the other, but we’ll get into that in just a moment.

We want to educate you on the cost of spray foam insulation and precisely what that means for you, so let’s get started.

Spray Foam Insulation Cost

Let’s cut through the confusion about how much spray foam insulation costs.

It's like when you're trying to find a straight answer online, but all you get are roundabout replies or super technical stuff that just doesn't click. And it's even worse when you do find some numbers, but they're not from the pros. That's like trying to guess the price of a full car repair when all you've got is the cost of the parts.

We're here to clear things up. RetroFoam of Michigan has been in the spray foam game for more than 20 years, and we’re all about keeping it real with the prices we quote.

So, let's break it down – how much is spray foam per square foot? Why is open cell foam different in price from closed cell foam? What else goes into the final cost? How do we figure out the size of your project? And how does all this save you cash over time?

Stick with me, and I’ll walk you through everything you need to know about the cost of spray foam insulation, no fluff, just facts.

insulation tax credits

Spray Foam Insulation Cost Per Square Foot

Alright, let’s break down this whole square footage thing in a way that makes sense. It's like when you’re trying to figure out how much spray foam you need and where to measure. You might think, "Hey, is it the whole room or just the part I’m insulating?"

It can sound like the same thing, but it’s really not. Let me paint a picture for you.

Imagine you're laying down new carpet in your living room. You’d measure the floor, right? Simple – length by width, and bam, you’ve got your number.

Now, if you’re looking to put siding on your house, you’re going to measure each wall on the outside because that’s what you’re covering up. Same deal if you’re insulating the walls – you’re measuring the space that's going to be wrapped up in that cozy foam.

For your attic, it’s like deciding whether you’re just laying down carpet (measuring the floor only) or if you’re doing a full roof job (measuring the slopes of the roof).

But here’s the kicker: You’re always focusing on the part that’s getting insulated, not the entire size of your space.

You might have heard some folks talking about 'board foot' for insulation projects. That's just a fancy way of saying a piece that's 1-foot by 1-foot by 1-inch thick. It’s like the insider lingo contractors use because that’s how they buy the stuff.

But let's be real, 'board foot' might as well be ancient Greek to most of us. We're more familiar with square footage because it’s easier to picture that space we’re filling with foam. Plus, it makes way more sense when we’re talking about the cost of spray foam insulation, right?

So, if a contractor buys a pile of insulation and knows their costs, they work out what to charge to make a profit. We want to keep it straightforward with square footage so you know exactly what you're getting and how much it’s going to cost, without all the industry jargon.

Closed Cell Foam Insulation Cost

Now you have a better understanding of the square footage your foam insulation contractor will use, let’s talk about closed cell insulation cost.

The cost of closed cell spray foam insulation will vary depending on several factors, so for the purpose of this article, I plan to do a range. I think examples might be easiest to understand here.

Two inches of closed cell spray foam costs around $3 to $4 per square foot for most existing residential projects. Two inches is needed for an air seal, so it is not recommended to spray any less than that. 

If more R-Value is needed to pass code or if a different application calls for it, three more inches of closed cell may be needed.

Now, you wouldn’t double that amount for each square foot. The insulation contractor uses that as a base cost before figuring out the total. Now, this total will vary due to several factors I’ll discuss later on.

For newly built homes, commercial buildings, and pole barns, the pricing is a little different because there are fewer complications and not as much difficulty when it comes to the install. Because of this and higher possible volume discounts, since the project sizes are typically much greater than an existing residential project, you can expect those closed cell spray foam insulation cost per square foot to be between 15 to 20 percent less than an existing home.

Open Cell Spray Foam Insulation Cost

So now you want to know how much does open cell spray foam insulation cost.

Three inches of open cell spray foam is typically in the range of $2.50 to $3 per square foot for most residential applications. Three inches is enough to provide an air seal and is the recommended amount to use for applications like open walls, crawl spaces, and rim joists.

When more thermal resistance is needed, like in the attic, more insulation is needed at a higher cost per square foot for the added thickness.

If you’re building a new home or pole barn, the open cell spray foam insulation cost per square foot could also be between 15 to 20 percent cheaper than an existing home due to the high volume of product used and fewer obstacles.

Looking for More Specific Spray Foam Insulation Costs Based on Your Project Type?

Something you might find helpful before I jump into the cost factors are these specific articles that discuss the cost to insulate an existing home, new build home, and pole barn. These articles can give you a range that will definitely be helpful.

How Much Does Foam Insulation Cost for an Existing Home? 

How Much Does Spray Foam Insulation Cost When Building a New Home?

How Much Does Spray Foam Insulation Cost for a Pole Barn?

What is the Potential Problem with a Spray Foam Insulation Cost Per Square Foot Price?

So, you know the spray foam insulation price per foot, but what are you going to do with it?

Do you know how to measure the square footage of your project? Do you know the difference between living space square footage and the total square footage of the insulated area?

These are things that can lead to some confusion when it comes to figuring out how much spray foam insulation costs. You might go into an estimate thinking one price and get hit with something completely different, or get unnecessary sticker shock and decide to go with a cheaper option.  

For example,  when determining the cost to insulate your attic with spray foam, it's easy to determine the square footage of the attic floor and multiply that by a square foot price. 

However, what if you multiply it by the 3-inches of open cell square foot price instead of the 6- to 10-inches of open cell square foot price that is needed for the attic roof deck? What about removing and disposing of the old attic insulation - are those costs extra? What if you have mechanicals in the attic, and it is best to insulate the roof deck instead of the attic floor - then your square-foot measurements will be pretty low. 

As you can see, it can be challenging for a homeowner to determine the cost of a project when having a square foot number since there are just so many factors to consider.

Maybe you do know the square footage or even how to measure it. The next thing you have to figure out is how thick that spray foam needs to be. That thickness is going to vary depending on what the project is and which spray foam you decide to use.

I promise I’m not teasing you, and I will explain how thick spray foam needs to be depending on the project and how it affects the cost, just not right now.

What Factors Determine Spray Foam Insulation Cost?

Just because you know the spray foam insulation cost per square foot and the square footage of your living area doesn’t mean that’s the end of it.

There are a lot of other things that are going to affect the total cost. Keep in mind there isn’t a set price for any of the factors because they come up on a case-by-case basis and can vary greatly depending on the contractor.

From the size of the area to be insulated to the difficulty of the job, let’s take a look at all of these factors that impact foam insulation cost. I do a deeper dive into some of these factors below.

  • The size of the area to be insulated with spray foam. The bigger the project, the higher the cost, and vice versa when it comes to pricing a spray foam insulation job.
  • Spray foam insulation material: open cell or closed cell spray foam. As we discussed above, there is a cost difference between open cell and closed cell spray foam.
  • Brand of spray foam insulation used. Not all foams are made the same, so you will get what you pay for, and cheaper isn’t always better.
  • The thickness of the spray foam applied. The air seal you are looking to achieve requires a certain thickness of the spray foam. The thicker the foam, the more expensive the project will get.
  • Preparation before the spray foam is applied. From laying down plastic to moving furniture, any prep work before the installation can add to the final cost.
  • The difficulty of the spray foam insulation project. If the space to be insulated is hard to access or any demo needs to take place is another factor that can raise the cost.
  • Are you eligible for discounts? We talked about things that can increase the price, but what about if you’re eligible for discounts? Some contractors offer discounts that can lower the total cost of the project.
  • Charges for mileage. There are contractors out there who charge mileage depending on the location of the job compared to where their home base is.
  • The area where you live. Just like the cost of living can be different in certain areas of the country, the cost of foam insulation can be vastly different as well, depending on where you live.
  • The type of contractor hired. Prices can vary from contractor to contractor as they come in different shapes and sizes. Some contractors are very small, while others have multiple crews. Others may specialize in only foam insulation, and others are considered a Jack of all trades.
  • Is there a lifetime warranty offered? The installation will likely cost more from a contractor compared to one that doesn’t offer any warranty. On the flip side, that lifetime warranty can save you money if there is any problem with the material or workmanship in the future.

The Size of the Area to Be Insulated with Spray Foam

This is kind of a no-brainer, as the size of the area to be insulated is the main factor in determining the cost of any insulation project. 

The larger the area to be sprayed with foam, the higher the cost of the project is going to be.

Spray Foam Insulation Material: Open Cell or Closed Cell Spray Foam

I mentioned before that there is a price difference between the open cell and closed cell spray foam.

This is another factor that can impact the total cost of your project because the open cell is the less expensive option when compared to the closed cell. For most homes, we recommend open cell spray foam, but there are instances when closed cell spray foam is the better fit.

When it comes to a pole barn, if the walls are going to be exposed, we recommend closed cell spray foam because it is durable and can take it when it’s knocked into. Open cell is usually what we call for when it comes to the ceiling, so it’s a bit of a mix-and-match.

In any case, whether you choose open cell or closed cell, you’ll be getting the air seal you’re looking for with foam insulation.

Brand of Spray Foam Insulation Used

Not all spray foams are created equal.

Different spray foam manufacturers will have different qualities, meaning you’re going to get what you pay for as far as fire rating, low VOCs, and performance.

Think of it like when you get gas for your car -- sure, you can get regular, mid-grade, or premium. You know that regular gas can get the job done, but you also know that the premium octane will make your car run more efficiently.

The Thickness of the Spray Foam Applied

Every project is going to be different, and in some cases, the amount of spray foam needed can also be different.

We usually recommend 6- to 10-inches of open cell spray foam on the roof deck or ceiling and 3-inches on the walls. Closed cell spray foam should be applied at 4- to 5-inches on the ceiling and 2- to 3-inches in the walls. These are the amounts required to create the air seal you’re looking for.

Depending on the state you live in, the insulation code may also dictate the thickness of the foam needed to pass. This all comes down to the climate zone you live in.

Preparation Before the Spray Foam is Applied

Any kind of prep work that needs to be done before the installation could have an additional price tag attached to it.

If there is anything in the immediate area where the foam is to be sprayed, maybe furniture or storage items in the home or vehicles in the pole barn, all of these items need to be moved or covered with plastic.

A good contractor will also cover the floors in the home, cabinets, and really anything that might get the spray foam on it during installation to make sure once they’re done, the home looks just like it did before they arrived.

Another aspect of prep work for the job would be removing any old insulation that is present where the foam is to be installed. Spray foam is a fresh start for your project, and that old insulation isn’t doing you any favors. That and the spray foam needs a clean surface to adhere to.

Now, you might be thinking that removing the old insulation yourself can save you some money, but it is a dirty, hard job. A good contractor will take that old insulation out and take care of it for you. If you try to remove it yourself, you have to do all the hard work, find someplace to dispose of it, and pay to throw it out. Honestly, in the long run, you’re better off letting the contractor deal with it.

Difficulty of the Spray Foam Insulation Project

A cost factor that may not be apparent at first is the difficulty of the job.

One of the more difficult aspects of the installation is gaining access to the space to be insulated.

If you have a cathedral ceiling in your home, the best way to tackle that is going to involve some cutting. 

The best method to insulate a cathedral ceiling is with spray foam insulation. One- to two-foot strips would need to be cut through the middle of the stud cavities on either side of the ceiling peak. The installer now has access to spray the ceiling cavity. Once the foam has been sprayed, the drywall is replaced, and a rough patch of mud is spread over the seams.

Another scenario that tends to be difficult for installation is accessing a tight crawl space or area under the floor.

This process will also require a little demo inside your home, as the installers will need to pull up the carpet or cut the wood.

Carpeted floors would need to be pulled up, and then the installer will cut one-foot access points around the perimeter of the room. This ensures that the foam can be sprayed into the cavity below. Once the foam has been sprayed, the cut strips are replaced, and the carpet rolled back out.

We recommend having a carpeting company come out to secure the carpet back into place.

Now, if you have wood flooring, the process is different.

The installation crew will cut at the tongue and groove of the wood floor so they can then cut one-foot strips to gain access. The foam is sprayed onto the cavity walls, and the flooring is replaced. A good contractor will make sure the wood flooring goes back down securely.

Ways to Reduce Spray Foam Insulation Cost

Many utilities offer energy-efficient rebates to encourage homeowners to update or add insulation to their homes. 

These rebates could be as small as around $50 for insulating the rim joist to as large as about $1,000 for insulating the entire home.

Most things you buy don’t pay you back, but the money saved on monthly energy bills will add up to be a net gain in the long term. Some customers have saved as much as up to 10 percent on their monthly bills on the low end, whereas others have seen their bills cut in half.

There are many factors that determine the amount you save on energy bills after your home has been insulated.

The size of your HVAC system can play a role in those savings. If the system is too big or too small for the size of your home, that can possibly cost you money. 

Your energy use habits can also play a role -- leaving lights on, thermostat settings, and leaving unused items plugged in also all play a role.

How Long Does it Take to Insulate a Project with Spray Foam?

Insulating your home with spray foam will take about two days -- one day for removal and one day for installation.

The first day of the install is spent removing the old insulation in the home. That old insulation has to go so the spray foam has a clean area to adhere to. The process of removing the old insulation takes about 4- to 6 hours. In a larger home, the time to remove existing insulation from the attic, rim joist, and crawl space could take a little longer.

Obviously, with new build construction or pole barns, there is no old insulation to remove, so that shaves a day off of the project right there.

The second day is when the magic happens. 

The installation crew arrives and begins to prep the project for the spray foam. We discussed this preparation above. Plastic is laid down to prevent overspray from getting onto items that couldn’t be moved out of the way, as well as covering windows, doors, and flooring.

After the prep work is done, the spray foam is applied. The time to complete the installation will depend on the scope of the project. Just spraying foam into the attic or crawl space could take just a few hours, while spraying a new build home or large pole barn from top to bottom could take one to two days.

Is Spray Foam Insulation Worth the Extra Cost?

Is your home or certain rooms in your home freezing in the winter and scorching hot in the summer?

Are frigid floors making your feet cold? Are uncomfortable drafts annoying your family? Outrageous energy bills putting a strain on your wallet? Spray foam in certain areas of your home could be the answer.

When it comes to the importance of comfort and energy efficiency, many homeowners have decided the benefits way outweigh the cost. That’s because many have found that foam insulation pays for itself over time.

Don’t take our word for it. Here are a few customer testimonials you might find helpful

Learn How Scott Saved Big Bucks on His Monthly Energy Bills with Foam Insulation

See How the Right Insulation Saved Daniel Thousands in Heating Costs

Flint Homeowner Drops Energy Usage by 40% With Foam Insulation and HVAC Upgrades

How Betty Jo Reduced Her Consumers Energy Bill in Half

Monthly Energy Bills Savings from Foam Insulation ‘Paid Itself Off’ in Just 5 Years, according to Homeowner Jack Lash

Other Services Offered with Spray Foam Insulation

  • Free estimate – A project manager will come to your home, take measurements, look for trouble areas, and then give you a quote of how much the project will cost. They will also discuss any discounts and rebates you could be eligible for at this time. The quote you get is concrete and won’t change unless the scope of work changes.
  • Free concierge program – A concierge is assigned to each customer and answers any and all questions and concerns. The concierge stays with the homeowner throughout the entire process. 
  • Help to complete financing – For customers who are looking to get their project financed, the project manager or a concierge will help walk the customer through the process and will discuss the best option for them.
  • Clean-up before the project – Almost every home has existing insulation in the attic, crawl space, or rim joist that will need to be removed. A good contractor will have a crew come out to remove the old insulation and dispose of it so the homeowner doesn’t have to worry about it.
  • Clean-up after the project is complete – After the insulation job is completed, the crew works to clean up any mess that was made during installation. The spray foam crew will clean up the plastic they laid down and make sure the inside of the home where they worked looks just like it did before they arrived.
  • Rebates – Most homeowners are eligible to receive rebates from their energy provider. A good contractor will offer to send those rebates in for the homeowner once the project is finished.
  • Lifetime Warranty – The lifetime warranty will cover the homeowner if there are any issues with the product itself or the workmanship of the job. The lifetime warranty is sent to the homeowner after the project is completed. This warranty is valid for the life of the home and is transferable if the home is sold.

Planning Your Project with Our Spray Foam Insulation Cost Calculator

Now that you’ve learned about the factors that determine the cost of spray foam insulation, it may be time to schedule an estimate with a spray foam insulation contractor. 

After reviewing and measuring your project, a good contractor will be able to give you an exact quote for the installation.

If you live in Michigan’s lower peninsula or the greater Toledo, OH area and are ready to schedule a free in-home estimate, give us a call at 866-900-3626 or fill out the form on our website

You can also check out our budget calculator to give you a rough idea of the cost of insulating your existing home or pole barn.

Related Articles

Injection Foam Insulation vs Spray Foam Insulation: What’s the Difference?

How to Plan and Pay for Your Foam Insulation Cost

Open Cell vs Closed Cell Foam Insulation: Which is Better for My Home?

Insulation Budget Calculator

About Amanda Ringler

Amanda previously has worked as a breaking news and crime reporter, TV news producer, and editor in Flint and Detroit. Throughout her career as a journalist, she has won several awards from The Society of Professional Journalists - Detroit Chapter and the Michigan Press Association. As part of the RetroFoam of Michigan family, Amanda uses her experience as a journalist to write content that will help educate homeowners on the benefits of foam insulation. When Amanda isn’t writing, she’s spending time with her husband and rescued huskies. She also loves knitting, making art, cooking, and hosting dinner and a movie night for friends and family.