What is Closed Cell Foam?

When it comes to insulating your home, closed cell spray foam is one of the most effective options available. But what exactly is it, and how does it work? In this article, we’ll break down the basics of closed cell spray foam insulation and explain why it’s a popular choice.

Closed cell spray foam is a type of insulation made from polyurethane that expands when applied to walls, floors, ceilings, or other surfaces. When the liquid is sprayed, it quickly expands into a foam plastic and hardens, becoming a dense, solid material. This dense structure makes it highly effective at insulating.

The term "closed cell" refers to the tiny bubbles, or cells, within the foam. In closed cell foam, these cells are mostly closed, trapping gas inside them. Trapping the gas, or blowing agent, gives closed cell foam its higher insulation value.

How Does Closed Cell Spray Foam Work?

When applied, the foam expands to fill cracks, gaps and voids, forming a continuous, seamless layer of insulation. Closed cell spray foam creates an insulation, air barrier and vapor retarder in a single application that reduces heat, air, and moisture movement in and out of a building.

The high per inch R-value and ability to seal air leaks makes closed cell foam one of the best options for improving energy efficiency. By preventing air from escaping your home in the winter or entering during the summer, it helps maintain a consistent indoor temperature, reducing the strain on your heating and cooling systems.

In addition to acting as a thermal boundary, closed cell spray foam also serves as a vapor retarder. This means it reduces moisture movement through the assembly, which is especially important in areas like basements, crawl spaces, or exterior walls where vapor control is a critical design concern.

Benefits of Closed Cell Spray Foam

There are several advantages to using closed cell spray foam insulation in your home:

1. High Insulating Properties (R-Value)

Closed cell spray foam has one of the highest R-values per inch of any insulation material, ranging from about R-6 to R-7 per inch. R-value measures a material’s resistance to heat flow, and the higher the R-value, the better the insulation. This means that closed cell foam provides excellent thermal performance, which will help keep your home warm in the winter and cool in the summer.

2. Air and Moisture Barrier

Because of its physical properties, closed cell spray foam acts as both an air barrier and a vapor retarder. It seals gaps and cracks, reducing air infiltration and vapor movement. Being proactive and managing moisture in this way can help reduce the risk of mold and mildew growth in your building.

3. Structural Strength

One of the unique benefits of closed cell spray foam is that it can add structural integrity to areas where it’s applied. Since the foam hardens into a rigid material, it can reinforce walls, roofs, and floors, making them more resistant to damage from wind or other forces. Some closed cell foam materials have even been tested in hurricane resistant applications.

4. Space-Saving

Because closed cell foam has a high R-value per inch, it provides excellent insulation without needing a lot of material. This makes it ideal for situations where space is limited, like in walls or tight crawl spaces.

5. Long Lifespan

Closed cell spray foam is extremely durable and can last for decades without replacement. Unlike traditional insulation materials, once applied, closed cell foam doesn’t sag, settle, shift, or lose its insulating properties over time, making it a long-term investment in your building’s energy efficiency.

Where is Closed Cell Spray Foam Best Used?

Closed cell spray foam is versatile and can be used in many areas of your home. However, it’s particularly useful in places where moisture protection and high insulation performance are important:

• Exterior Walls: Closed cell spray foam’s ability to act as an insulator, air barrier and a vapor retarder makes it ideal for exterior walls, especially in northern climates that experience high vapor drive during winter months.
• Basements and Crawl Spaces: These areas are often prone to moisture problems. Closed cell foam can help manage vapor movement while providing a high level of insulation.
• Attics: Due to the air barrier qualities of closed cell foam it can be used in accordance with the building code to create vented or unvented attics.
• Roofs: Closed cell foam can also be used to insulate roofs, reducing air and moisture movement while adding structural strength.
• Limited Space: In areas where space is tight or where you want to maximize insulation in a limited area, closed cell foam is an excellent choice.

Is Closed Cell Spray Foam Right for Your Home?

If you’re looking for a highly efficient, durable, and versatile insulation solution, closed cell spray foam may be the right choice for you. It offers superior thermal performance, protects against air and moisture infiltration, and can even add structural strength. While it comes with a higher upfront cost than some other insulation options, its long-term benefits in energy savings and durability make it a worthwhile investment.

Need help deciding if closed cell spray foam is the best option for your project? Our team of experts can assess your home and provide recommendations tailored to your insulation needs. Contact us today for more information!