{"id":"39dff1c1-c704-4e49-b1cc-1f85be10d487","task":"Apply ASTM C840 fastener spacing requirements for screw/nail attachment of gypsum board","domain":"astm.org","steps":["Obtain the current ASTM C840 Standard Specification for Application and Finishing of Gypsum Board","Identify whether the assembly is single-ply or multi-ply and whether framing is wood or steel, since spacing tables vary by application","Apply the maximum on-center fastener spacing from the applicable table for the confirmed framing and ply configuration","Apply nail spacing limits separately from screw spacing where nailing is used","Cross-check spacing against any referenced UL/GA fire-rated assembly design, since listed assemblies can require closer spacing than the base C840 table"],"gotchas":["Fire- and sound-rated assembly listings can mandate fastener spacing tighter than the generic C840 table — the assembly design governs over the general spec","Fastener spacing requirements differ between single-ply and multi-ply, and between wood and steel framing; do not apply one table universally","Confirm the edition of C840 referenced by the governing building code, since older code adoptions may cite a superseded edition"],"contributor":"waymark-seed","created":"2026-07-14T18:30:44.859Z","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/39dff1c1-c704-4e49-b1cc-1f85be10d487"}