Is Closed Cell Spray Foam Fire Resistant?

Closed-cell spray foam insulation has gained popularity in recent years due to its exceptional thermal performance and ability to create an airtight seal. However, is closed cell spray foam fire resistant? In this article, we will delve into the topic of closed-cell spray foam’s fire resistance and explore its characteristics, performance in fire tests, and how it can contribute to enhancing overall fire safety measures in buildings.

Before delving into the fire resistance properties of closed-cell spray foam, it is important to understand its basic characteristics. Closed-cell spray foam insulation is a type of polyurethane foam that is applied as a liquid and expands to fill gaps, crevices, and cavities. 

Unlike open-cell spray foam, which has interconnected air pockets, closed-cell foam is comprised of densely packed cells that are closed off from one another, resulting in a rigid and compact structure.

Also, closed-cell spray foam is known for its excellent thermal insulation properties, providing high R-values and minimizing heat transfer. It also serves as an effective air and moisture barrier, preventing air infiltration and reducing the risk of condensation within walls or attics. These attributes make closed-cell spray foam a popular choice for energy-efficient construction.

Performance in Fire Tests:

When it comes to fire resistance, closed-cell spray foam exhibits favorable properties. It has a relatively high melting point and low flammability, contributing to its ability to withstand fire. Closed-cell foam has been tested and classified as a “Class 1” or “Class A” material according to various fire safety standards, indicating its excellent resistance to flames and its limited contribution to fire spread.

During fire tests, closed-cell spray foam insulation typically resists ignition and combustion. It forms a protective char layer when exposed to flames, which acts as a barrier against further heat transfer and flame penetration. This charring effect slows down the foam’s burning rate and reduces the release of smoke and toxic gases.

Contribution to Fire Safety Measures:

In addition to its inherent fire resistance, closed-cell spray foam insulation can also contribute to enhancing overall fire safety measures in buildings. Its ability to create an airtight seal helps prevent the movement of smoke and hot gases, limiting the spread of fire within a structure. 

This containment can buy valuable time for occupants to evacuate safely and allow firefighters to control the blaze more effectively.

Furthermore, closed-cell spray foam can help improve a building’s overall fire rating by sealing gaps and cracks, reducing the potential for fire to spread through hidden voids and channels. 

By creating a continuous barrier, it can compartmentalize different areas of a building, slowing down the progress of the fire and providing additional time for evacuation and emergency response.

Is Closed Cell Spray Foam Flammable?

Is Closed Cell Spray Foam Flammable

Closed-cell spray foam insulation is not considered flammable in its cured state. However, it’s important to understand the properties and limitations of closed cell spray foam when it comes to fire safety.

Closed-cell spray foam is composed of two liquid components that are mixed on-site during application. These components react and expand to form solid foam insulation with closed, gas-filled cells. Once the foam cures, it becomes rigid and provides excellent insulation properties.

One of the advantages of closed cell spray foam is its fire-resistant nature. Due to its high density and the presence of trapped gas within the cells, it acts as a barrier to heat and can inhibit the spread of fire. Closed-cell foam has a relatively low heat transfer rate, which can help reduce the likelihood of ignition and the rapid spread of flames.

However, it’s important to note that while closed cell spray foam has fire-resistant properties, it is not entirely fireproof. When exposed to high temperatures or direct flame, it can charge and release combustible gases. The foam can burn, but it tends to do so slowly and may self-extinguish when the flame is removed. Additionally, the burning of closed cell spray foam may produce smoke and toxic gases, so adequate ventilation is crucial.

To enhance fire safety, building codes, and regulations often require additional fire protection measures when using spray foam insulation, such as the installation of a thermal barrier or ignition barrier. These barriers can provide additional time for occupants to evacuate in case of a fire and can prevent the foam from igniting or releasing toxic gases.

What Spray Foam Is Fire Resistant?

There are several types of spray foam insulation available in the market, and some of them offer fire-resistant properties. One commonly used fire-resistant spray foam insulation is called “closed-cell spray foam.”

Closed-cell spray foam insulation is composed of tiny cells that are tightly packed together, creating a dense and rigid structure. This type of foam contains a high percentage of closed cells, which means that it has a lower permeability to air and moisture compared to open-cell foam.

The fire resistance of closed-cell spray foam comes from the chemical composition of the foam and its ability to restrict the flow of heat. The closed-cell foam contains fire retardant additives, such as polymeric flame retardants, that help to reduce its flammability and inhibit the spread of flames. 

These additives can be mixed with the foam during the manufacturing process to enhance its fire-resistant properties.

When exposed to fire, closed-cell spray foam insulation forms a char layer, which acts as a protective barrier against heat transfer. This char layer helps to slow down the spread of fire and can provide additional time for occupants to evacuate a building. The closed-cell foam also has a higher melting point than open-cell foam, making it more resistant to heat.

It is important to note that while closed-cell spray foam is fire-resistant, it is not fireproof. In the event of a severe fire, the foam can still combust or break down. 

Therefore, it is crucial to adhere to local building codes and regulations regarding fire safety and use additional fire protection measures as required, such as installing fire-rated materials, fire barriers, and smoke detectors.

When considering spray foam insulation, it is recommended to consult with professionals who specialize in insulation installation. They can guide you in selecting the appropriate type of spray foam insulation that meets your specific requirements, including fire resistance.

Does Closed Cell Spray Foam Need a Fire Barrier?

Closed-cell spray foam insulation does not always require a separate fire barrier. However, the need for a fire barrier depends on various factors, including building codes, local regulations, and the specific application of spray foam insulation.

Closed-cell spray foam has inherent fire-resistant properties due to its dense and compact nature. It forms a rigid and solid barrier that can slow down the spread of flames and restrict the entry of oxygen, which is necessary for combustion. This characteristic allows the closed-cell foam to provide some level of fire resistance on its own.

Building codes and regulations often dictate whether or not a fire barrier is required for spray foam insulation. These codes may vary depending on the location and the intended use of the building. In some cases, a separate fire barrier, such as drywall or intumescent coatings, might be necessary to meet fire safety standards.

Here are a few factors to consider regarding the need for a fire barrier with closed-cell spray foam insulation:

  1. Building Codes: Check the local building codes and regulations to determine if a fire barrier is mandatory for spray foam insulation in your area. Building codes usually provide specific guidelines and requirements for insulation materials and fire safety.
  2. Occupancy and Use: The intended use of the building can influence fire safety requirements. Commercial or public buildings may have more stringent regulations compared to residential properties.
  3. The thickness of the Foam: The thickness of the closed-cell spray foam can affect its fire resistance. Thicker foam generally provides better fire retardant properties, which may reduce the need for an additional fire barrier.
  4. Assembly Configuration: The assembly or construction method also plays a role. For example, if the spray foam is covered with a fire-resistant material like a gypsum board, it may satisfy the fire barrier requirements.

It is crucial to consult with local authorities, building professionals, or experts in the field to ensure compliance with fire safety regulations when using closed-cell spray foam insulation. They can provide specific guidance based on your location, building type, and project requirements.

Is Closed Cell Foam Heat Resistant?

Is Closed Cell Foam Heat Resistant

Closed-cell foam is generally known for its heat resistance properties. The closed cell structure refers to the foam’s composition, where the individual cells are completely enclosed and separated from each other. 

This structure provides several advantages when it comes to heat resistance:

  1. Insulation: Closed-cell foam is an excellent insulator, which means it has low thermal conductivity. It effectively slows down the transfer of heat through conduction, reducing the amount of heat that can pass through the material. This property makes closed-cell foam ideal for applications where heat insulation is required, such as building insulation or automotive insulation.
  2. Thermal stability: Closed-cell foam is typically made from materials that exhibit good thermal stability. These materials can withstand high temperatures without deforming, melting, or breaking down. For instance, closed-cell foam can be made from materials like polyethylene, polyurethane, or neoprene, which have high melting points and can tolerate elevated temperatures.
  3. Fire resistance: Closed-cell foam can also possess fire-resistant properties. Depending on the specific composition and additives used, closed-cell foam can be designed to be self-extinguishing or have a low flame spread rating. Some closed-cell foams are manufactured with fire retardant additives, which enhance their ability to resist ignition and slow down the spread of flames.

It’s important to note that the heat resistance of closed-cell foam can vary depending on the specific material used and the manufacturing process. Some closed cell foams are engineered to withstand higher temperatures than others. 

Therefore, it is crucial to consider the intended application and select a closed cell foam that meets the necessary heat resistance requirements.

While closed cell foam provides good heat resistance, extreme temperatures can still affect it. Exposing closed cell foam to very high temperatures for prolonged periods can eventually lead to degradation or changes in its physical properties. 

Therefore, it’s essential to consult the manufacturer’s specifications and guidelines to ensure the foam’s suitability for specific temperature ranges and durations.

What Kind of Foam Is Used for Fire?

Foam used for fire suppression is commonly referred to as firefighting foam. It is specifically designed to extinguish fires by smothering the flames and preventing the release of flammable vapors. Firefighting foam is typically composed of water, a foaming agent, and various additives that enhance its performance.

The primary purpose of firefighting foam is to create a physical barrier between the fuel (the material burning) and the oxygen in the air. 

By doing so, it effectively cuts off the fire’s oxygen supply and cools down the fuel surface, extinguishing the flames. The foaming agent plays a crucial role in generating foam with the desired properties.

There are several types of foam used for fire suppression, and their selection depends on the specific fire hazards and requirements. Here are three common types:

  1. Aqueous Film-Forming Foam (AFFF): AFFF is a widely used foam that consists of water, fluorochemical surfactants, and various additives. It forms a thin, heat-resistant film on the fuel surface, creating a barrier against oxygen. The film helps to smother the fire, preventing re-ignition. AFFF is particularly effective on hydrocarbon-based fires, such as gasoline or oil fires.
  2. Alcohol-Resistant Aqueous Film-Forming Foam (AR-AFFF): This type of foam is specifically designed for fires involving polar solvents like alcohols, which can break down ordinary foams. AR-AFFF contains specialized additives that form a protective barrier between the foam and the alcohol, preventing its penetration. It also forms a film on the fuel surface to extinguish the fire.
  3. Protein Foam: Protein foam is derived from animal protein sources and is commonly used for combating fires involving flammable liquids like ethanol, diesel, or crude oil. It forms a thick, stable blanket on the fuel surface, which suppresses the release of flammable vapors and cools down the fuel, extinguishing the fire. Protein foam is known for its excellent burn-back resistance.

These are just a few examples of firefighting foam types, and there are variations and specialty foams available for specific applications. 

Firefighters and fire safety professionals are trained to select the appropriate foam type based on the fire’s characteristics and the materials involved to achieve effective fire suppression.

Is Spray Foam Flammable After It Dries?

Spray foam insulation is a popular material used for insulating buildings and sealing gaps and cracks. There are two main types of spray foam insulation: open-cell and closed-cell foam. The flammability of spray foam insulation depends on the type and specific formulation of the foam, as well as its installation and any additional fire-retardant treatments it may have undergone.

Open-cell spray foam insulation is generally more susceptible to flame and can be flammable after it dries. Open-cell foam has a lower density and contains tiny cells that are not completely closed, allowing air to fill the open spaces. The open-cell structure of this foam makes it permeable to air and moisture. While open-cell foam can provide excellent thermal insulation, it generally does not possess significant fire-resistant properties on its own.

Closed-cell spray foam insulation, on the other hand, has a higher density and features cells that are completely closed. This type of foam has a much lower air permeability and greater resistance to moisture. Closed-cell foam is generally more resistant to flame and can offer some degree of fire retardancy. However, it is important to note that closed-cell spray foam insulation is not inherently fireproof.

It is crucial to understand that even though closed-cell foam offers some fire resistance, it can still ignite and burn under certain conditions, especially when exposed to high temperatures or direct flames. Additionally, factors such as the thickness of the foam, its installation quality, and the presence of any additional fire-retardant coatings can impact its flammability characteristics.

To enhance the fire resistance of spray foam insulation, additional fire-retardant treatments or coatings can be applied. These treatments are designed to inhibit the spread of flames and reduce the flammability of the foam. It is essential to consult with professionals and follow local building codes and regulations to ensure proper installation and fire safety measures when using spray foam insulation.

Recommended Post: Is It Safe To Microwave In Styrofoam

What Are the Disadvantages of Closed Cell Spray Foam?

What Are the Disadvantages of Closed Cell Spray Foam

Closed-cell spray foam insulation has numerous benefits, such as high R-value, excellent air sealing properties, and moisture resistance. However, there are a few disadvantages associated with this insulation method. 

Here are some of them:

  1. Cost: Closed-cell spray foam insulation is generally more expensive compared to other insulation materials like fiberglass or open-cell spray foam. The cost can be a limiting factor for some homeowners, especially for larger projects.
  2. Installation complexity: Proper installation of closed-cell spray foam requires expertise and specialized equipment. It is typically performed by professionals, and incorrect installation can lead to poor performance and reduced effectiveness.
  3. Environmental concerns: Closed-cell spray foam is made from chemical components, including polyurethane, which can release volatile organic compounds (VOCs) during the installation process. VOCs can have a negative impact on indoor air quality and may cause respiratory issues in sensitive individuals. It is important to ensure proper ventilation during and after installation.
  4. Rigid nature: Closed-cell spray foam is rigid and inflexible once cured. While this can provide structural support and added strength to walls, it can also cause problems if there is any movement or shifting in the building structure. If not accounted for during installation, it can lead to cracks and other issues.
  5. Moisture concerns during installation: Closed-cell spray foam is sensitive to moisture during the installation process. If there is excessive moisture present on the surfaces being sprayed, it can affect the curing process and the overall performance of the insulation.
  6. Difficulty in retrofitting: Closed-cell spray foam is challenging to retrofit into existing buildings or structures because it requires access to the entire wall cavity or area being insulated. This can be particularly problematic in renovation projects where access is limited.

It is important to consider these disadvantages alongside the benefits of closed-cell spray foam insulation when making decisions about insulation materials. 

Consulting with insulation professionals and understanding the specific requirements of your project can help determine whether closed-cell spray foam is the right choice for you.

What Is the Melting Point of Closed Cell Foam?

Closed cell foam refers to a type of foam structure that contains numerous small, sealed air bubbles or cells within its matrix. The melting point of closed cell foam depends on the specific material from which it is made. 

There are various types of closed cell foam available, such as polyethylene foam, polyurethane foam, and neoprene foam, each with its own unique characteristics and melting points.

Polyethylene foam, which is a common type of closed cell foam, typically has a melting point ranging from 110°C to 130°C (230°F to 266°F). However, it’s important to note that closed cell foam does not melt in the same way as materials like metal or plastic. Instead, when exposed to high temperatures, closed cell foam undergoes a process called thermal decomposition.

Thermal decomposition occurs when the foam material breaks down chemically due to the heat, resulting in the release of gases and the structural collapse of the foam. The specific temperature at which thermal decomposition begins depends on the foam’s composition and the additives used during its production.

It’s worth mentioning that closed cell foam is often chosen for its ability to resist high temperatures, making it suitable for applications where thermal insulation or heat resistance is required. However, if the foam is exposed to temperatures exceeding its thermal limits, it will eventually degrade and lose its insulating properties.

To ensure the safe and effective use of closed cell foam, it’s important to consult the manufacturer’s specifications or technical data sheets for the specific type of foam you are using. These documents typically provide detailed information regarding the foam’s melting point, thermal properties, and recommended temperature limits.


To wrap up the topic: is closed cell spray foam fire resistant? Closed cell spray foam generally exhibits fire-resistant properties. The closed cell structure of the foam helps to limit the spread of flames and the passage of heat, making it a suitable choice for applications where fire protection is a concern. 

The specific fire resistance rating of closed cell spray foam can vary depending on the product and its formulation. It is important to consult the manufacturer’s specifications and certifications to determine the foam’s exact fire-resistant properties and compliance with relevant fire safety standards. 

Additionally, it’s worth noting that while closed cell spray foam can provide fire resistance, it is not inherently fireproof. Proper installation, adherence to building codes, and the inclusion of additional fire safety measures are still crucial for overall fire protection in any given application.