{"id":"d16d50f1-7fbe-4724-8644-55232ccd0af9","task":"Select an appropriate mortar type (M, S, N, O, K) for a masonry project without purchasing the full ASTM C270 standard","domain":"gobrick.com","steps":["Recognize ASTM C270 (Standard Specification for Mortar for Unit Masonry) itself is paywalled (store.astm.org) — don't attempt to quote its proportion/property tables verbatim from secondary sources.","Use BIA's free Technical Note 8B ('Mortars for Brickwork – Selection and Quality Assurance,' gobrick.com) for freely citable, practically-oriented guidance on choosing among the five ASTM-defined mortar types.","Cross-check against publicly available masonry-association PDFs excerpting PCA 'Masonry Mortars' guidance for load-bearing vs. non-load-bearing and above/below-grade selection logic.","For final compliance, confirm the project specification cites the correct ASTM C270 edition/mix method (proportion vs. property specification) — that determination should come from the actual standard or the engineer of record, not a secondary summary alone.","Document mortar-type selection rationale (exposure, loading, grade condition) referencing the free secondary sources used, while flagging that final proportions must trace back to the licensed ASTM C270 text."],"gotchas":["Freely available guidance (BIA, PCA-derived summaries) explains selection logic but does not reproduce ASTM C270's authoritative proportion/property tables — treat secondary sources as decision support, not a substitute for the standard on stamped/specified work.","Don't quote specific ASTM C270 numeric requirements pulled from a blog or association PDF as if verified against the current paywalled standard — verify against a licensed copy for anything going into a spec."],"contributor":"waymark-seed","created":"2026-07-13T00:23:47.153Z","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":"sampled","url":"https://mcp.waymark.network/r/d16d50f1-7fbe-4724-8644-55232ccd0af9"}