The presence of HVAC equipment alone does not determine the fire protection requirements for spray polyurethane foam (SPF). Instead, contractors should evaluate how the attic is classified under the applicable building code, how the space will be accessed and whether the specified foam and coating system has been tested for the intended application. Taking the time to verify these details before installation can prevent costly callbacks and inspection delays when an attic ignition barrier is called for.
HVAC Equipment Doesn’t Automatically Trigger a Thermal Barrier
A common misconception is that any attic containing mechanical equipment must receive a thermal barrier. In reality, code requirements are based on the occupancy and use of the space rather than the simple presence of ducts or an air handler.
Many attics containing mechanical equipment are considered service spaces with limited access. Depending on the project and the applicable code, an approved ignition barrier assembly may be permitted instead of a thermal barrier. However, this determination should always be supported by the appropriate code provisions and the documentation for the specific spray foam system being installed.
Rather than relying on previous projects or assumptions, contractors should verify that the coating, spray foam product and application thickness match a tested assembly. The authority having jurisdiction (AHJ) will often expect supporting documentation demonstrating that the installed system complies with the applicable acceptance criteria and evaluation reports.
Specify a Tested Assembly from the Start
Choosing an intumescent coating is only part of the specification process. Contractors should also confirm that the coating has been evaluated with the selected spray foam product and for the intended application. Applying a product outside its tested scope can create unnecessary challenges during inspection.
IFTI provides comprehensive technical documentation for DC315 Intumescent Coating, including approved assemblies and application guidance for spray polyurethane foam. For projects requiring supporting documentation during plan review or inspection, contractors can also access the DC315 Submittal Package, which consolidates key technical information into a single resource.
It’s equally important to follow the published installation requirements, including the specified wet film thickness, dry film thickness and coverage rates. Even an approved product may not comply if it is applied outside the manufacturer’s tested parameters. Whether you’re bidding a residential attic retrofit or a large commercial SPF project, don’t assume that ducts or an air handler automatically dictate the required fire protection. Review the applicable code, specify a tested assembly and document the installation properly.
IFTI supports contractors with tested DC315 systems, technical resources and application guidance that help keep projects moving from specification through final inspection.