Continuous InsulationInsulationA2P1043: A Closer Look: Comparing Spray Foam Insulation and Rigid Foam for Continuous Insulation Systems

April 11, 2023


When it comes to selecting the proper insulation for your building project, there are many options on the market, making it challenging to determine which type is the best choice for your individual project needs. Spray foam insulation and rigid foam insulation are two common types used in continuous insulation systems, but how can you know which one is right for you?

In this article, we will provide an in-depth comparison of spray foam insulation and rigid foam insulation and discuss the advantages and disadvantages of each. In addition, we will look at the performance, cost, and installation process of these two types of foam insulation to help you make an informed decision when selecting insulation for your project.

Overview of Spray Foam Insulation

Spray foam insulation is a unique type of insulation that provides benefits unmatched by other insulation materials. It combines two chemicals to create a polyurethane foam that can be sprayed into cavities, gaps, or surfaces. Once applied, the foam expands and hardens into a thick layer provided thermal insulation and air sealing. There are two types of spray foam insulation: open-cell and closed-cell.

  • Open-Cell Spray Foam:
    • Open-cell spray foam  is a type of insulation that is composed of tiny cells that are not completely closed, allowing air and moisture to pass through. Open-cell spray foam is sometimes used in exterior walls, but it is not ideal for all situations.
    • Open-cell foam has a lower R-value per inch than closed-cell foam, which makes it less effective at insulation. It is a nonstructural insulation that can achieve a nominal R-value of R-3.5 to 4 per inch.¹ Additionally, open-cell foam is more porous and can absorb moisture, leading to mold problems and structural damage over time.
  • Closed-cell Spray Foam:
    • Closed-cell spray foam has a higher density than open-cell spray foam insulation. It has a nominal R-value of R-6 to 8 per inch and seals well enough to act as an air and vapor barrier, which helps reduce air infiltration and improves indoor air quality. Closed-cell spray foam insulation is watertight and more durable than open-cell spray foam insulation, typically making it a better choice than open-cell spray foam for exterior walls.
    • Additionally, closed-cell spray foam insulation can help to reduce mold growth since it is impervious to moisture. As a result, this type of insulation can help reduce the risk of health problems associated with mold and mildew. Closed-cell spray insulation foam has a minimal expansion rate and a rigid structure, making it ideal for places with more extreme temperatures.²

Knowing the differences between open-cell and closed-cell foam can help you make the best decisions for your building envelope insulation needs. Overall, open-cell spray foam insulation can be used with continuous insulation systems;  however, it is not as effective as closed-cell spray foam insulation. In a continuous insulation system, closed-cell spray foam provides excellent thermal performance and air-sealing properties.

Spray foam insulation is particularly useful in continuous insulation systems designed to maximize thermal performance and building health. Spray foam insulation can help reduce thermal bridging. Thermal bridging is when heat is transferred across a building envelope through areas of high thermal conductivity, such as wood or metal studs in walls. Continuous insulation systems are intended to provide a thermal break between interior and exterior environments, reducing energy consumption and improving comfort.

Spray foam insulation can be used as a continuous insulation system component and applied directly to the wall, ceiling, or roof deck between girts, creating an unbroken layer of insulation that mitigates thermal bridging. It can also be combined with other insulation materials, such as mineral wool or rigid foam boards. When used with other materials, the foam fills gaps and seals around penetrations, further reducing energy loss and increasing efficiency.

Overall, spray foam insulation is a powerful tool for creating an energy-efficient and comfortable building. Its use in continuous insulation systems can significantly improve energy performance, reduce energy costs, and provide greater comfort for building occupants.

Napoleon High School | Spray foam insulation material

Pros and Cons of Spray Foam Insulation

Spray foam is an excellent choice for insulation because of its ability to provide a high level of thermal performance and air sealing and its ability to fill in awkward and hard-to-reach areas. There are several advantages to consider when installing spray foam insulation.

The primary advantage of spray foam is its ability to provide a high level of thermal performance. In addition, it can form an air seal that can help prevent air leakage. This airtight seal means it can help to reduce heating and cooling costs significantly.

The downside to spray foam insulation is the cost. It can be more expensive than other types of insulation. Additionally, it is not recommended to use in specific applications, such as areas with high humidity or dampness. In these cases, types of traditional insulation, such as rigid foam board, may be a better option.

Overall, spray foam can be an effective and efficient material for continuous insulation. Still, it is essential to consider the associated costs and potential complications of expanding foam, when deciding whether or not it is the right choice for your project.

Overview of Rigid Foam Insulation

Rigid foam insulation is a popular choice for commercial buildings due to its high R-value. it is made from a variety of materials including polyisocyanurate (polyiso), expanded polystyrene (EPS), extruded polystyrene (XPS), and polyurethane (PU). Rigid foam boards are available in a range of thicknesses and sizes, allowing for easy installation in walls, ceilings, and floors.

Rigid foam insulation is highly effective and can provide an R-value up to R-7 per inch of thickness, making it one of the most efficient insulation materials available. It is non-flammable, water resistant, and can be installed easily. Additionally, since rigid foam insulation does not absorb moisture, which can help prevent mold growth and structural damage.

Overall, rigid foam insulation is an effective and efficient way to improve the energy efficiency of a building. It is relatively easy to install and provides excellent insulation and air-sealing capabilities. When installed correctly, it can provide long-term energy savings and improved comfort levels throughout the property.

Brick Cladding | Kiewit University

Pros and Cons of Rigid Foam Insulation

Rigid foam insulation is one of the most popular materials in continuous insulation systems. It is a lightweight, energy-efficient material that provides excellent thermal insulation and is moisture-resistant. But as with any material, rigid foam insulation has advantages and disadvantages.

Rigid foam board insulation has a relatively high R-value per inch (up to R-8 per inch), which means it provides greater thermal insulation and efficiency compared to other common insulation materials.³ Rigid insulation can also act as a moisture barrier, preventing moisture from penetrating the building envelope while also acting as an air barrier, which improves indoor air quality and reduces the risk of drafts and heat loss. A durable material, rigid foam insulation can withstand harsh weather conditions and normal wear and tear.

However, rigid foam board insulation requires careful installation to avoid gaps and ensure the insulation is sealed correctly. Improper installation can lead to reduced insulation effectiveness and energy loss.

Despite necessary installation requirements, rigid foam board insulation can be a good choice for specific situations. It is essential to consider all insulation options to determine the best type of insulation for your particular project needs.

How to Choose the Right Type of Foam Insulation for Your Building Project

When choosing the right type of foam insulation for a building project, it is important to consider a variety of factors, including the climate, the location of the building, the building’s design, and construction.

The location and climate of the building play a significant role in choosing which type of foam insulation to use for your project. For example, for buildings located in areas with high moisture levels, such as coastal regions, closed-cell spray can provide a tight seal and act as a vapor barrier, making it an ideal option for moisture-prone areas. However, rigid foam insulation can also act as a vapor barrier with the addition of necessary accessories such as tape and caulk.

The building’s design and layout also play a role in selecting foam insulation. For example, a building with many corners or unusual shapes may require foam insulation that can be easily customized and shaped to fit the contours of the building. In such cases, spray foam insulation may be a more suitable choice.

Building construction is an essential factor when determining the type of foam insulation to use. For example, rigid foam insulation is commonly used for a building with open framing because of its rigidity and strength; whereas spray foam may be used on a closed-framing structured as a base is provided for the spray foam to adhere to.

In summary, building construction plays an essential role in determining the type of foam insulation to use. Architects and designers must evaluate the structural requirements, moisture levels, climate, and building design to select insulation that provides optimal energy efficiency and long-term performance.


When deciding between spray foam and rigid foam insulation for your project, weighing the advantages and disadvantages of both materials is essential. Spray foam insulation is excellent for achieving a tight insulation gap due to its expansive nature; however, it may not provide enough additional structural support or be ideal for all applications. On the other hand, rigid foam boards can provide more thermal efficiency than spray foam while providing extra structural support.

Ultimately, there is no one-size-fits-all solution; instead, identifying the best foam insulation solution depends on the unique requirements of each project. Consider environmental factors such as temperature ranges and climate conditions and other factors such as airflow control and fire ratings to ensure you choose the correct type of insulation so that your project will be protected against weather elements and energy leakage in the long run.

SMARTci Continuous Insulation Systems with Spray Foam and Rigid Foam Insulation

SMARTci continuous insulation systems, by Advanced Architectural Products, can be used with various insulation materials, including mineral wool, spray foam, and rigid board insulation, to provide advanced, best practice, and effective insulation solutions. The SMARTci system consists of pre-engineered assemblies designed to fit together like puzzle pieces, creating a seamless insulation barrier over the building envelope.

One of the key benefits of the SMARTci system is its universal compatibility with substrates, insulation, and cladding. This allows architects, designers, builders, and contractors to choose the insulation type that is best suited for their specific project needs. Whether using spray foam or rigid foam insulation within the SMARTci system, architects and builders can achieve optimal energy savings, efficiency, and long-term performance.

Overall, the SMARTci continuous insulation system is a versatile and effective solution that allows architects and builders to customize the insulation to their specific project requirements. Its compatibility with spray foam and rigid insulation ensures that the building envelopes are fully insulated and provide optimal energy efficiency, reducing costs and promoting sustainability.

If you are interested in learning more about SMARTci continuous insulation systems, visit our website or contact us today!

© 2023 Advanced Architectural Products


  • ¹ Johns Manville. “Commercial Spray Foam Insulation.” Johns Manville, 2021,
  • ² U.S. Department of Energy. “Types of Insulation.”, 12 June 2017,
  • ³ Steffen, Ted. “What Is the R-Value of Foam Board Insulation?” Attainable Home, 1 May 2020,

If you wish to receive our latest news, sign up for our mailing list!

Advanced Architectural Products Logo

Creating engineered best practice continuous insulation solutions, while leaving the world a better place than when we started.


If you wish to receive our latest news in your email box, just subscribe to our newsletter!

959 Industrial Drive, Allegan, MI 49010  |  (269) 355-1818

© Copyright 2024 Advanced Architectural Products. All Rights Reserved.

Patents Privacy Policy