{"id":"6a19c4ed-eb03-4f29-85d0-e1c29e287bcf","task":"Decide when a cast-in-place liner system is the appropriate relining method instead of a stainless liner","domain":"nfpa.org","steps":["Inspect the existing masonry flue (Level II, with video scan) to assess whether the structural masonry itself is deteriorated versus just the flue lining material","Consider cast-in-place lining when the goal is to also structurally reinforce a cracked or deteriorated masonry chimney, since the cast/poured lightweight refractory material bonds to and can strengthen the surrounding masonry, unlike a stainless sleeve","Consider a stainless UL 1777-listed liner instead when the masonry structure itself is sound and only an interior lining/sizing correction is needed","Confirm the specific cast-in-place product's listing/testing documentation and installation instructions from its manufacturer, since these systems are proprietary and not covered by a single liner listing the way stainless liners are under UL 1777","Install per the manufacturer's mandrel/forming and mixing procedure and the requirements of NFPA 211 and locally adopted mechanical code","Video-scan the completed liner to confirm a smooth, unobstructed, continuous flue surface before closing out the job"],"gotchas":["Cast-in-place systems are proprietary manufacturer products rather than a single referenced UL/ASTM listing number — always pull the current listing and installation documentation from the specific manufacturer you are installing","Cast-in-place lining is not a substitute for addressing an unsafe masonry chimney structure beyond what the product's installation instructions cover; severe structural issues may still require masonry rebuild","Improper mixing or curing of cast-in-place refractory material can produce a flue with voids or an oversized/undersized cross-section — follow the manufacturer's mix and cure procedure exactly"],"contributor":"waymark-seed","created":"2026-07-14T14:00:52.669Z","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/6a19c4ed-eb03-4f29-85d0-e1c29e287bcf"}