Meeting the International Fire Code with Spray Foam Insulation

Fire safety isn’t just a good idea—it’s the law, enforced through the international fire code (IFC). For Indiana property owners installing spray foam insulation, understanding IFC requirements and how they relate to the IBC and IRC is essential for safe, compliant construction. 

Spray foam is a combustible material. While it performs exceptionally well in sealing air leaks and providing high R-values, it must be protected by fire-rated barriers to meet international fire code standards. The IFC outlines specific fire resistance rules that dictate how spray foam can be used in residential, commercial and mixed-use structures. 

Understanding Barriers, Coatings and Code Exceptions 

The most critical component of fire safety with spray foam is the installation of thermal or ignition barriers. These are required in areas where spray foam is exposed or accessible to occupants, such as garages, basements, crawl spaces and attics. 

A thermal barrier—typically a ½" layer of gypsum board—is used to delay the temperature rise of the foam in a fire. This gives people more time to evacuate and slows down the spread of flames. In limited-access areas, such as mechanical spaces or non-habitable attics, the international fire code allows for the use of ignition barriers instead. These may include materials like 1.5" mineral wool, 0.5" wood panels or sheet metal. 

Another option for code compliance is using intumescent coatings—spray-on fire-retardant materials that expand when exposed to heat, forming a protective char layer. When tested under standards like NFPA 286 or UL 1715, these coatings can be approved alternatives to drywall. However, they must have current ICC-ES (Evaluation Service) documentation verifying code compliance. 

For builders working with closed-cell spray foam, which is denser and has a higher R-value, the material’s structure provides better fire resistance than open cell spray foam—but not enough to eliminate the need for protection. Both types must still comply with thermal barrier regulations. 

Some areas offer exceptions to these requirements. According to the IBC building code, SPF applied in roof assemblies that are part of a Class A, B or C fire-rated roofing system and meet test standards such as UL 1256 may be exempt from additional barriers. Likewise, if the foam is applied against a surface like masonry or concrete with a thickness of 1" or more, it may qualify for a reduced requirement depending on the occupancy type and fire load. 

Additionally, areas like rim joists and sill plates may be exempt from thermal barrier rules if the foam passes ASTM E84 with a flame spread index of 75 or less and a smoke-developed index of 450 or less. 

Ensuring Fire Code Compliance on Indiana Projects 

Staying compliant with the international fire code means more than just knowing the rules—it means understanding how they apply to each specific project. In Indiana, many local building departments follow state-modified versions of the 2021 IRC and IFC guidelines, which are based on nationally recognized model codes. The state’s adoption of spray foam installation codes is overseen by the Indiana Fire Prevention and Building Safety Commission. 

Residential and commercial buildings are held to different standards. A single-family home might allow ignition barriers in an attic, but a multifamily building or commercial facility could require full thermal protection and additional coatings. Accessibility also factors in. If a space is used for storage, walk-through traffic or houses mechanical systems, it is more likely to require enhanced fire protection under the code. 

Proper insulation planning includes identifying these variables during the design phase. That’s why we assess every space—garages, rim joists, attics and mechanical rooms—to determine the correct barrier strategy. We also consider the air sealing performance needed to meet energy standards and whether Indiana spray foam code permits specific applications based on location, use and occupancy. 

Our team works with builders, remodelers and property owners across Indiana to make sure all spray foam projects are safe, efficient and code-compliant. We install both open cell and closed-cell spray foam and apply intumescent coatings when necessary to meet fire protection standards. We also provide documentation for code inspectors to verify that all materials and applications align with international building and fire codes. 

International Fire Code - Indiana - M.Y Insulation Has the Answers

Contact us to schedule an insulation assessment or get a quote on your upcoming project. We proudly serve Fort Wayne, Carmel, South Bend and surrounding communities across Indiana with certified spray foam solutions.