Firestop Penetrations in a Two-Hour Corridor Wall
During the final inspection of a four-story hotel renovation, the inspector examines a 2-hour fire-resistance-rated concrete masonry corridor wall. Three penetrations are visible: (1) an 8 in. PVC drain pipe with a 2 in. annular space, sealed with mineral wool and a bead of acrylic caulk labeled "firestop"; (2) a 2 in. steel conduit with a 1/2 in. annular space, sealed with the same caulk; and (3) a 6 in. steel pipe with a 1 in. annular space that is unsealed. The contractor says the caulk is "UL classified" and that no shop drawings were required because the wall is existing. The hotel is fully sprinklered and the corridor wall separates guest room suites from the corridor. The inspection is scheduled for tomorrow, and the contractor wants a sign-off.
1. Evaluate each of the three penetrations. State whether the installed condition is acceptable and why.
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A caulk label alone does not make a firestop system. Each penetration must match a listed system for the specific wall type, penetrant material, diameter, annular space, and sealant.
8 in. PVC with 2 in. annular space: PVC is combustible and melts; many systems require a specific intumescent wrap or collar, not just mineral wool and acrylic caulk. A 2 in. annular space is large, and the caulk alone is unlikely to be a listed system. This condition is not acceptable without a system number and installation instructions that exactly cover it.
2 in. steel conduit with 1/2 in. annular space: Steel conduit can sometimes be sealed with a listed caulk or sealant system, but the annular space, wall type, and conduit size must fall within the listing. The contractor must produce the system documentation. "UL classified caulk" is not enough.
6 in. steel pipe, unsealed: This is an open penetration in a 2-hour wall and is clearly noncompliant. It must be sealed with a listed system.
The inspection should also verify the required F rating and whether a T rating is required by the listed system and code; do not assume one from the caulk label.
2. What inspection, testing, and documentation should exist for these penetrations before the inspector signs off?
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The inspector should require, before sign-off:
- an approved firestop submittal identifying each listed system by number, with the manufacturer's installation instructions;
- evidence that the system matches the wall construction, penetrant type and size, annular space, and sealant depth;
- special inspection records for firestopping, typically under ASTM E2174 for installed firestops, performed by an approved agency;
- photos of each penetration before and after sealing, with a location key;
- a field inspection report noting any deviations and their resolution.
The contractor's statement that shop drawings were not required because the wall is existing is incorrect. Existing rated construction does not waive the requirement to maintain the rating. The special inspector should also verify that the annular space and mineral wool packing match the listed system, because field substitutions are common failure points. Without system documentation and inspection records, the penetrations cannot be signed off.
3. The contractor asks for a temporary sign-off so the ceiling can close. What should the inspector do, and what corrective action is required?
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The inspector should not issue a sign-off for noncompliant firestopping. Closing the ceiling would conceal the penetrations and make future inspection difficult.
The corrective action is:
- stop closure in the affected corridor;
- require removal of the unlisted caulk/mineral wool where it does not match a listed system;
- install a listed firestop system for all three penetrations, including the unsealed steel pipe;
- provide the system numbers, manufacturer instructions, and special inspection records;
- re-inspect before the ceiling is closed.
A temporary approval could be considered only for areas that are fully compliant and clearly separated from the deficient work, and only if the inspector documents the open deficiencies. The final report should identify each penetration, the deficiency, the corrective action, and the re-inspection result. The owner should retain the firestop submittals and inspection reports with the life-safety documents.