IBC 2603.4.1.9 - Foam Plastic Insulation in Garage Doors: The Fire Code Exception

Insulated garage doors use foam plastic to achieve their R-values. Foam plastic in buildings normally requires a thermal barrier to slow fire spread. IBC 2603.4.1.9 is the exception that allows foam-core garage doors to skip that barrier if the door assembly passes a specific fire test.

What this section says

IBC Chapter 26 governs foam plastic insulation in buildings. The general rule under Section 2603.4 is that foam plastic must be separated from the building interior by an approved thermal barrier: typically 1/2-inch gypsum board. Without a thermal barrier, foam plastic can ignite quickly and release toxic gases.

Section 2603.4.1 lists specific exceptions where foam plastic may be used without a thermal barrier. Subsection 2603.4.1.9 is the garage door exception. The UpCodes summary states:

"This section addresses foam plastic insulation in garage doors where fire-resistance ratings are not required."

It allows garage door assemblies to contain foam plastic without a thermal barrier when the door passes the fire test in ANSI/DASMA 107.

ANSI/DASMA 107 is titled "Room Fire Test Standard for Garage Doors Using Foam Plastic Insulation." It is a full-scale room fire test in which the door assembly is installed in a room corner. The test measures heat release rate, flame spread, and other fire performance metrics. A door that passes DASMA 107 has demonstrated that its foam core does not significantly contribute to fire growth in a realistic scenario, making the thermal barrier unnecessary.

This provision applies where fire-resistance ratings are not required, meaning it does not eliminate the fire separation assembly required by R302.6 (drywall on the garage walls). It addresses only the door assembly itself.

When it applies

IBC 2603.4.1.9 applies in commercial construction governed by the IBC. The parallel provision for residential construction is addressed through the IRC by reference to IBC 2603.4.1.9 or similar exceptions.

Any commercial garage door with foam plastic insulation must either:

1. Have an approved thermal barrier covering the foam on the interior side, or
2. Comply with the DASMA 107 fire test exception under 2603.4.1.9

Most commercially available insulated sectional garage doors are manufactured to meet DASMA 107. The product documentation and the door's spec sheet confirm whether the specific model has been tested to DASMA 107.

What this means for you

Ask for the DASMA 107 test documentation. When specifying an insulated garage door for a commercial facility, request confirmation that the door assembly has been tested to ANSI/DASMA 107. This documentation supports the permit application and AHJ review.

The thermal barrier exemption is product-specific. Not all foam-insulated doors are automatically exempt. The exemption only applies to door assemblies that have actually passed the DASMA 107 test. A door with foam core but no DASMA 107 documentation must have a thermal barrier.

R-value and fire compliance are separate questions. A high R-value door (R-18 or R-21) uses substantial foam. More foam does not mean more fire risk if the assembly passed DASMA 107. The test evaluates the complete assembly, not just foam thickness.

Residential applications are also affected. The IRC references IBC 2603 provisions or includes parallel language. Confirm with the local AHJ whether IBC 2603.4.1.9 or an equivalent IRC provision applies to your residential project.

G Brothers can provide DASMA 107 test documentation for commercial insulated door models we supply. We include this in permit packages for commercial projects.

Full text and source

Read IBC 2024 Section 2603.4.1.9 at https://up.codes/s/garage-doors. ANSI/DASMA 107 is available from DASMA at dasma.com.

IBC 2603.4.1.9 applies to foam plastic in garage door assemblies. It does not exempt the garage walls from the fire separation requirements of IBC Section 706 or the IRC's R302.6.