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Why Spray Foam Insulation Is Best

January 15th, 2024 | 4 min read

By Alexis Dingeldein

You've heard that spray foam insulation is the best insulation product on the market. You know spray foam has a hefty price tag, but you aren't sure if it is worth the cost. Why should you invest your money in one of the most expensive insulations available?

South Central Services has insulated hundreds of projects with spray foam. While we install other products like cellulose and batting, we chose spray foam as our primary product because of the value it offers homeowners.

Spray foam isn't the right product for every application. Still, there are reasons why spray foam is reported as the best insulation around.

By the end of this article, you will understand why spray foam insulation is often best. Specifically, you will know:

  • Why spray foam insulation is versatile
  • Why spray foam insulation offers high performance
  • Why spray foam insulation is permanent

Spray Foam Insulation Is Versatile.

Many insulation products can only be used for specific applications. Either the properties of the insulation do not allow it to be installed, or the insulation cannot hold up in every area of a home.

For example, blown-in insulations like fiberglass and cellulose are almost always reserved for attic applications. Professionals can densely pack blown-in cellulose into new construction wall cavities, but as DIY, blown-in products are reserved for attics.

Batt insulation is more versatile than blown-in but still cannot be used in every application. In addition to attics, batt insulation can also be installed in interior walls and between floors. However, the fiberglass batts often installed in basements and crawl spaces end up molding and functioning poorly as insulation. Batt insulation should not be used in below-grade applications.

Compared to these popular insulation products, spray foam insulation is incredibly versatile. Between the two spray foam variations of open cell and closed cell, spray foam can be used for any of the following applications.

  • Basements
  • Crawl spaces
  • Attics
  • Exterior walls
  • In-between floors

You could even install spray foam in interior walls, though we don't recommend it. Spray foam offers more performance than interior walls need, and is not worth the investment.

While you have to know which spray foam is best for your application, you are guaranteed that a spray foam product can deliver outstanding results for almost any project.

Spray Foam Insulation Offers High Performance.

You can measure the performance of spray foam in two different ways: R-value and air-sealing capability. One of these measurements is the traditional gauge of insulation performance, while the other has become more prevalent with recent advances in building science.

Let's examine each of these in more detail.

Spray Foam Insulation Has A High R-Value.

R-value, or resistance value, is the traditional measurement of insulation performance. If you visit a Home Depot or Lowe's insulation aisle, you'll find the term "R-value" plastered on most insulation packaging.

R-value measures how well a material resists thermal heat transfer. By this traditional measurement, the best insulations have high R-values. A fiberglass batt with an R-value of R-19 will be cheaper than an R-49 batt because the latter offers better performance.

The R-value of spray foam is measured per inch of insulation installed. Closed cell spray foam has an R-value of approximately R-7, while open cell spray foam's R-value is about R-3.7. With only 3 inches of foam, closed cell spray foam can surpass the R-value of a 6.5 inches thick R-19 batt.

Spray Foam Insulation Can Create An Airtight Seal.

Air sealing is a newer measurement of insulation performance. 60 years ago, houses in America were not commonly air-sealed. Instead, air was allowed to flow through the house's gaps, cracks, and crevices. The idea that houses needed to breathe was prevalent. Unfortunately, the air escaping from these homes was expensive, conditioned air.

As advancements were made in mechanical ventilation, where machines control the airflow and air quality in your home, air sealing became more common. Airflow became controlled instead of air leaking randomly.

A home's gaps, cracks, and crevices must be sealed off to create this airtight seal. Spray foam is manufactured while installed, allowing it to adhere to the surface it is sprayed against. The adhesion of spray foam to its substrate creates an airtight seal. No other insulation adheres to the surface it is installed against.

Put simply, if you want to save money on energy bills and control the air quality in your home, spray foam is the insulation product you need.

High Performance Means Lower Energy Bills.

What do high R-values and airtight seals mean practically for homeowners? Homes insulated with spray foam have lower energy bills than homes with traditional insulations. The high R-value of spray foam gives excellent performance with conductive heat transfer.

Spray foam's airtight seal prevents air from escaping the home. In the winter, the air you pay to heat stays inside and keeps you warm. You don't crank the thermostat to replace the heat leaking from your home, so your energy bills stay down. The hot outside air does not exchange with your cool and conditioned air in the summer.

Spray Foam Insulation Is Permanent.

The fact that spray foam can be installed almost anywhere and perform well is made better by its product lifetime. If you had to replace your insulation every 15 to 20 years for it to keep working well, it might not be worth the cost. Spray foam insulation is so expensive, no one could afford to invest thousands every few decades: and no one has to.

Spray foam insulation is a permanent insulation. Spray foam is actually a type of polyurethane plastic created through a chemical reaction. Spray foam does not shrink, settle, or sag over time. Its high performance after 1 month will stay the same after 30 years.

The only thing that can break down spray foam insulation is ultraviolet rays from sunlight. For applications like commercial roofing that use spray foam, additional coatings are added to protect from UV rays.

No other insulation product is permanent like spray foam. Blown-in insulations settle over time. Batt insulation is prone to sagging. For most insulations, two product lifetimes must be considered: perfect conditions and real-life applications. Spray foam has proven itself in real-world applications to remain effective for the lifetime of a building.

The Bottom Line About Why Spray Foam Insulation Is Best

If you're looking for a great insulation product, spray foam is the best all-around choice. Spray foam is versatile in its application options, so it can almost always be a viable choice for home improvement projects. Spray foam is a permanent solution, so you'll never have to debate insulation options or replacements again.

Best of all, spray foam offers a 2-in-1 performance that other insulation products cannot compete with. The air-sealing ability and high R-value of spray foam make it an excellent option for attics, basements, crawl spaces, and exterior walls.

Spray foam is an expensive option. Use these resources to determine if spray foam is within your budget.

Alexis Dingeldein

Alexis has been fascinated by spray foam insulation since 2018. When she isn’t thinking about insulation, Alexis is geeking out over storytelling and spreadsheets.