Find every location where foam plastic insulation faces an interior space, then check that the wall, roof, and floor sections, the finish schedule, and the specifications show the same thermal barrier, and that any barrier accepted on a test has matching evidence. AI can flag conflicts; the architect and the authority having jurisdiction decide compliance.
What does NFPA 275 cover?
NFPA 275 is the Standard Method of Fire Tests for the Evaluation of Thermal Barriers. NFPA’s page states that the standard presents a method for qualifying the fire performance of a thermal barrier to evaluate its ability to prevent ignition from a standard fire exposure or delay its occurrence.
NFPA’s official NFPA 275 page identifies the 2022 edition as current when checked on October 11, 2026. Confirm the edition, local amendments, and project scope that actually govern the work. The publisher’s newest edition does not establish local adoption.
The adopted building code decides where foam plastic needs a thermal barrier and which materials are accepted; see the IBC guide or the IRC guide. Exterior walls with foam often also rely on the NFPA 285 guide. Record which barriers the design accepts on a test before comparing.
Gather every section that shows foam insulation
Collect the wall, roof, and floor sections and assembly types, the building sections, the finish schedule, the insulation specifications (board, spray foam, and insulated panels), the interior finish and coating specifications, and the manufacturer’s data and test evidence for any barrier or coating accepted on a test.
Spray foam in attics, crawl spaces, and service rooms is often noted only in the specifications. Upload them with the drawings so those spaces are checked as well.
Follow the foam to the barrier that covers it
| Review question | Sources to compare | Decision to record |
|---|---|---|
| Foam locations | Wall and roof sections, insulation specifications | Confirm every assembly with foam plastic insulation is identified the same way on the drawings and in the specifications. |
| Interior face | Sections, finish schedule, interior elevations | Check that each foam assembly facing an interior space shows a thermal barrier in every source. |
| Barrier material | Finish schedule, specifications, assembly types | Find barriers named as one material on the sections and another in the finish schedule or specifications. |
| Tested barriers and coatings | Product data, test evidence, specifications | Match any barrier or coating accepted on a test with its documentation and the assembly it covers. |
| Exposed foam spaces | Attic, crawl space, and service room plans, specifications | Ask the architect to confirm the protection for foam in spaces with no finish shown. |
| Insulated panels | Panel data, wall types, interior finish | Identify insulated metal panels left exposed on the interior without a stated basis. |
The insulation specifications guide and the metal wall panel guide follow the same assemblies from the specification side, and exterior walls connect to the IBC Chapter 14 guide.
Example: spray foam left exposed in a storage room
Hypothetical example. A warehouse office addition specifies spray foam on the underside of the roof deck. The building section shows gypsum board below the foam in the offices, while the finish schedule lists the adjoining storage room as exposed structure with no ceiling and no coating.
The specifications place spray foam on the roof deck over the storage room, but the finish schedule shows exposed structure with no thermal barrier or coating there. Please confirm the protection for the foam in that room and coordinate the finish schedule and specifications.
The architect adds a barrier or a coating with supporting evidence and updates the schedule. Compliance is decided by the architect and the authority having jurisdiction.
Review thermal barriers with Groundbook
Upload the current project PDFs and relevant specifications to Groundbook. Identify the governing issues and add the applicable NFPA 275 reference from a copy you are licensed to use, where the license permits uploading it. State the edition, amendments, review area, and known exclusions in your instructions.
Compare the wall, roof, and floor sections, assembly types, building sections, finish schedule, insulation and coating specifications, and product data and test evidence. Flag foam plastic assemblies whose thermal barrier is missing or differs between sources, and tested barriers without matching evidence. Use the supplied NFPA 275 edition and adopted building code where applicable and cite both sources.
Groundbook links each potential finding to the sheets involved and the reference you uploaded.
Document review does not test a barrier or coating, interpret a test report, or approve an assembly. Those decisions remain with the architect and the authority having jurisdiction.