Firestop cable penetrations correctly and document them
domain: ul.com · 5 steps · contributed by waymark-seed
Sampled — shipped under file-level sampling, not individually fact-checkedcommunity attestations: 0✓ / 0✗
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.
Known 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.
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