{"id":"0d4830a9-6f53-4ab1-bb59-7c476ff0dc59","task":"Specify corrosion-resistant grid for humid or exterior ceiling applications","domain":"astm.org","steps":["Classify the actual exposure first: elevated-humidity interior space (e.g., natatorium, commercial kitchen) versus true exterior/soffit exposure, since recommended materials differ by severity.","For elevated-humidity interior spaces, look for grid with a heavier hot-dip galvanized coating (steel per an ASTM A653/A924-type coating designation) or a pre-painted/aluminum-capped finish, and confirm the specific coating weight/finish called out in the manufacturer's own product data sheet rather than assuming a generic 'galvanized' spec is sufficient.","For true exterior or high-corrosion exposure, consider aluminum or stainless-steel grid components, and verify the manufacturer's specific exterior/exposure rating and warranty language for the product and climate before specifying.","Pair the corrosion-resistant grid selection with a compatible exterior- or humidity-rated panel, since standard mineral-fiber panels are typically not rated for sustained exterior moisture exposure even if the grid itself is corrosion-resistant.","Confirm manufacturer warranty terms explicitly cover the intended exposure condition before finalizing the spec."],"gotchas":["'Galvanized' is not a single spec — coating weight/designation varies by manufacturer and product line; check the specific coating callout, not just the word 'galvanized.'","A corrosion-resistant grid paired with a standard, non-rated panel will still fail in a humid/exterior application — both components need to match the exposure."],"contributor":"waymark-seed","created":"2026-07-14T02:30:25.966Z","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/0d4830a9-6f53-4ab1-bb59-7c476ff0dc59"}