Model performance before the walls close up
Assembly-specific dew-point and vapor-permeability analysis, thermal-bridging review, and R-value performance verification — for the actual climate zone your project sits in, not a generic national assumption.
Four elements of a moisture & thermal review
Dew-point analysis
Modeling where condensation is likely to occur within the assembly, and whether the specified SPF layer thickness keeps the foam's interior surface above the dew point for the project's climate zone.
Vapor-permeability review
Confirming which vapor-retarder class (Class I, II, or III per IRC R702.7) the assembly needs, and whether the specified foam type and any additional layers meet it — including where open-cell foam requires a supplemental vapor strategy.
Thermal bridging analysis
Identifying where framing, headers, and structural transitions are undermining the assembly's whole-wall R-value, and quantifying the realistic performance gap versus the nominal cavity-fill rating.
Moisture-drive & climate context
Accounting for the direction moisture is likely to move through the assembly seasonally — inward drive in hot-humid climates, outward drive in cold climates — which affects where a vapor retarder should sit, not just whether one is required.
Condensation problems are expensive to find after the fact.
A wall or roof assembly can pass inspection and still trap moisture behind an undersized foam layer or a mismatched vapor strategy — a problem that often isn't visible until sheathing rot, mold, or a finish failure shows up years later. Modeling the assembly's moisture and thermal behavior at the design stage is materially cheaper than a forensic investigation after the fact.
- Analysis specific to the project's actual IECC climate zone
- Documented basis for any recommended assembly change
- Can feed directly into a spec-review or code-compliance engagement
Moisture & thermal analysis, answered
A dew-point analysis models where, within a wall or roof assembly, moist air is likely to reach its condensation temperature. For SPF assemblies, the initial foam layer generally needs to be thick enough to keep the foam's interior surface above the dew point — a layer that's too thin can still allow condensation to form inside the cavity even though the foam itself is correctly cured.
Not always — prescriptive tables like IRC R702.7.1 are built to avoid dew-point problems for typical assemblies. A project-specific analysis becomes more valuable for unusual assemblies, mixed insulation strategies, or climate zones and building types near the edge of what the prescriptive tables anticipate.
Vapor permeability is how readily water vapor diffuses through a material over time; air leakage is bulk air movement through gaps and penetrations, which can carry far more moisture, far faster, than diffusion alone. Closed-cell SPF performs well on both fronts in most assemblies, which is part of why it's specified — but the two need to be evaluated separately.
Yes. Wood and especially steel framing conduct heat far faster than the insulation around it, and cavity-only insulation strategies can lose a meaningful share of their nominal R-value to framing, headers, and rim-joist transitions — commonly cited in building-science literature in the range of 19–28% for wood-framed walls, which is a major reason the 2021 IECC pushed continuous insulation requirements into more climate zones.
Model the assembly before it's built
Send us the assembly type and project location, and we'll scope a dew-point and thermal-performance analysis for your climate zone.