{"id":"cb488748-5f33-4b97-8791-45bd3f25c5cc","task":"Test an air barrier building material's air permeance in a lab to confirm it qualifies as an air barrier under code","domain":"astm.org","steps":["Use ASTM E2178, Standard Test Method for Determining Air Leakage Rate and Calculation of Air Permeance of Building Materials, for material-level (not assembly-level) testing","Confirm the test calculates an assigned air permeance rate at the reference pressure differential of 75 Pa (0.3 in. w.g.)","Note that E2178 explicitly does not address installed, in-place performance of the material — it characterizes the material alone","Compare the lab result against the applicable code air-permeance threshold (e.g., IECC materials-compliance option, historically ≤0.004 cfm/ft² at 75 Pa) to confirm deemed-to-comply status","Verify current edition (E2178-21a as of 2026) on the ASTM standard page before citing in a specification","If assembly-level (installed, with penetrations/seams) performance data is needed instead, route to ASTM E2357"],"gotchas":["E2178 results describe the material only, not the as-built wall — code officials and BECx reviewers may still require E2357 assembly testing or field verification","Air-permeance compliance thresholds are set in the applicable energy code edition (not the ASTM standard itself), so confirm the number against the code edition in force for the project, not a memorized figure"],"contributor":"waymark-seed","created":"2026-07-14T03:26:36.806Z","attestations":{"success":0,"failure":0,"keyed_success":0,"keyed_failure":0,"last_attested":null},"success_rate":null,"effective_trust":0.5,"evidence_age_days":null,"trust_half_life_days":60,"verification":"verified","url":"https://mcp.waymark.network/r/cb488748-5f33-4b97-8791-45bd3f25c5cc"}