Once the desire for spray foam has been established, the next question many are faced with is often, "what is the difference between closed cell and open cell spray foam?" With such a wide variety of insulation materials available on the market, understanding the differences between open cell and closed cell spray foam is essential for homeowners and contractors looking to achieve ideal project results. 

Both open cell and closed cell spray foam are spray-applied plastics that are manufactured on the job site by the installer. ISO and resin materials from 2 separate drums are heated, pressurized, combined, mixed, and installed using specialized equipment.

Closed cell foam offers superior insulating properties, moisture resistance, and structural support. Open cell foam's higher expansion, lower cost, and sound-dampening properties make it a perfect choice for many residential applications. Recognizing the distinctions between these two products enables contractors & homeowners to tailor insulation strategies to each project's needs, ensuring maximum performance and customer satisfaction.

What is Closed Cell Spray Foam?

Closed cell spray foam insulation features a compact structure with fully closed cells. The resulting product features a higher percentage of plastics when compared to the air-filled contents of open cell. Closed cell acts as an air barrier at around 1.5 inches and offers some of the best thermal resistance properties among all insulation materials. This characteristic makes it the go-to choice for commercial & industrial applications where efficiency, consistency, and longevity are essential. 

In addition to its high performance, the moisture-resistant properties of closed cell make it an excellent choice for applications where moisture control is crucial. Closed cell can also be used as a vapor barrier, greatly enhancing its utility. 

What is Open Cell Spray Foam?

Open cell spray foam insulation has a more open structure that lets air fill the cells inside, which gives the foam its softer qualities. Many who are new to the industry believe this means air can move freely throughout the foam. This is not true. While less efficient, open cell also acts as an air barrier when installed at around 3.5 inches; however, it does not possess the same vapor barrier properties as closed cell foam. Overall, open cell foam stands out as an excellent choice for various residential & soundproofing applications. It is also available at a more affordable price point compared to closed cell options.

Choosing Between Closed Cell and Open Cell Spray Foam: Key Differences and Applications

Density

Closed cell foam, often called two-pound foam, has a typical density of 2 lbs. per cubic foot. At up to four times the density of its open cell counterpart, closed cell is a much more rigid material once installed. The inherent density of closed cell insulation contributes to its ability to reinforce the stability of existing structures. Open cell foam, often called half-pound foam, has a typical density of ½ lbs. per cubic foot. The open cell structure creates a much softer product, allowing it to be broken apart with the fingers. 

R-Value and Expansion

To appreciate the effectiveness of spray foam, it's important to understand R-value. R-value is a number that indicates a material's thermal resistance, essentially measuring a material's effectiveness in resisting the flow of heat. Closed cell foam generally has an R-value of 6.5 - 7.5 per inch, providing a higher R-value than most other insulation materials on the market. In colder climates, closed cell foam is almost exclusively favored due to its superior efficiency, though its use extends beyond these regions. During installation, closed cell foam expands to 30 times its original liquid volume.

With an R-value of approximately 3.5 per inch, open cell foam is not as effective as closed cell in preventing heat transfer, though it is not without its unique benefits. Once installed, open cell expands significantly more than closed cell, reaching 120 times its original liquid volume. This ability to expand makes open cell an excellent option when insulating hard-to-reach areas. 

Cost Differences

Closed cell spray foam will always be the most expensive way to reach any given R-value. This is due to the higher price of the blowing agent used & comparatively greater plastic content when compared to open cell. Both closed and open cell spray foam insulation are products designed for life-long effectiveness and premium performance. Expect to invest 2-3 times more in spray foam insulation than traditional insulation materials. Though premium options, the substantial energy savings and enhanced longevity of both types of insulation will compensate for this initial cost difference throughout the building's lifespan, making it a wise choice for long-term value. 

Which one is Right for You?

Understanding the moisture & ventilation properties of your project is the first step to ensuring a quality spray foam installation. Both open cell and closed cell spray foam insulation offer superior insulating properties compared to industry alternatives. Beyond enhancing a building's energy efficiency and reducing heating/cooling costs, these insulation types offer distinct benefits tailored to specific project & environmental needs.

Despite its higher cost, closed cell foam is considered a premium option chosen by those seeking top-quality insulation. Closed cell is the most frequently used material in modern commercial applications due to its ability to maintain a constant temperature effectively. It is also often applied in residential roofs, walls, attics, crawl spaces, and pole barns. In cold climates, closed cell is the go-to choice due to its higher R-value, rigidity, and performance.

Open cell makes an excellent choice for interior & exterior walls, attics, and anywhere that needs soundproofing. Open cell is also the least expensive of the two products, making it a more cost-effective option in many scenarios.

Specialty Products & Insulation Is Ready to Support Your Spray Foam Insulation Needs

Understanding the differences between open cell and closed cell spray foam insulation is crucial for making informed decisions about your project's efficiency and comfort. Specialty Products & Insulation stands ready to support contractors nationwide with business support, spray foam training, spray foam equipment, and premium commercial spray foam materials. 

We aim to elevate the industry standard by empowering contractors with the knowledge, tools, and resources needed to excel in their projects. Whether you're undertaking residential, commercial, or industrial insulation projects, SPI is here to ensure that you have the support you need to tackle new challenges and seize opportunities. From in-depth training sessions to business support that helps you navigate the market; SPI is committed to your success.