Catch assembly problems before they're built
An independent building-science review of a proposed SPF assembly — checked against R-value targets, vapor-retarder requirements, thermal-bridging mitigation, and applicable code — before it goes to permit or gets built.
Four things we verify in every spec review
R-value vs. climate zone
The 2021 IECC ties minimum cavity and continuous-insulation R-values to climate zone — for example, walls in zones 5–6 commonly need R-20+5ci or R-13+10ci. We confirm the specified foam type and thickness actually delivers the required whole-assembly performance, not just the nominal per-inch rating.
Vapor-retarder class
IRC Section R702.7 defines Class I (≤0.1 perm), Class II (0.1–1.0 perm), and Class III (1.0–10 perm) vapor retarders, with specific climate zones requiring Class I or II on the interior side. High-density closed-cell SPF can function as a code-recognized Class II retarder; low-density open-cell generally can't, which changes what else the assembly needs.
Thermal & ignition barriers
IRC R316.4 requires foam plastic to be separated from occupied space by an approved thermal barrier (commonly ½-inch gypsum) unless a tested exception applies. Attics and crawl spaces accessed only for service have a narrower ignition-barrier allowance under R316.5. We confirm the spec addresses whichever condition applies.
Thermal bridging at transitions
Cavity-only foam can lose meaningful whole-wall R-value to framing, headers, and rim-joist transitions. We flag where continuous insulation, tapered furring, or a revised detail is warranted to hit the assembly's actual performance target, not just its cavity number.
A marked-up spec you can act on.
A spec review typically results in a written memo with the assembly detail marked up directly — flagged issues, a recommended fix for each, and the code or performance basis for the recommendation, so it can go straight back to the design team or the GC without a second round of interpretation.
- Scoped as a fixed fee for a defined set of assemblies or drawings
- Typically a 1–2 week turnaround from receipt of drawings
- Can be paired with a follow-up call with the design team
Spec review questions, answered
Ideally before the assembly is finalized in construction documents — while there's still room to adjust foam type, thickness, or vapor-retarder strategy without triggering a change order. A review after permit submittal or after installation can still catch problems, but it's more expensive to fix by that point.
The proposed R-value against the applicable IECC climate-zone requirement, whether the foam type and thickness combination is capable of hitting that R-value in the available cavity depth, the vapor-retarder class the assembly needs versus what the spec provides, thermal-bridging mitigation at framing and transitions, and whether thermal-barrier or ignition-barrier code requirements are addressed for any exposed foam.
Stamping requirements vary by state licensure and project type — that's a conversation for your specific project and jurisdiction, and something we'll be direct about during scoping rather than assuming either way.
Yes. Dew-point and vapor-drive behavior is climate-zone-specific, so every review is done against the IECC climate zone for the actual project location, not a generic national assumption.
Get a spec reviewed before it's built
Send us the assembly detail and we'll scope a fixed-fee review against R-value, vapor-retarder, and code requirements for your climate zone.