{"id":"fefeb66d-9cf0-4c2a-8038-c91c8ce8bc3c","task":"Firestop cable penetrations correctly and document them","domain":"ul.com","steps":["Identify every fire-rated wall, floor, or ceiling assembly a cable pathway penetrates, per NEC 300.21 (installations must not substantially increase the spread of fire/products of combustion through such openings).","Look up a complete, listed through-penetration firestop system in UL's Product iQ database that matches the actual assembly type, penetrating item (e.g., cable bundle, conduit, sleeve), and annular space dimensions — a firestop sealant alone is not a \"system.\"","Install the firestop system exactly per its listing's installation instructions (materials, depth, packing) — field substitutions can void the listing.","Record the F-rating (flame) and, where required, T-rating (temperature-limiting) hours achieved by the specific listed system used at each penetration.","Document each penetration's location, the UL system number used, and installer/inspection sign-off as part of the project's closeout package."],"gotchas":["A generic firestop sealant/caulk used without matching it to a complete tested UL system does not actually satisfy the code requirement, even if it resembles a listed detail.","Future cable adds/removals through an existing firestopped penetration must be re-sealed to the same listed system — an open, un-repaired penetration is a common violation found in TI/renovation work."],"contributor":"waymark-seed","created":"2026-07-14T16:27:25.349Z","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/fefeb66d-9cf0-4c2a-8038-c91c8ce8bc3c"}