Firestopping
Corpus sync: neutrality remakes, note hygiene, datasheet relocation, transformer-split cross-refs
Showing changes from Rev 3
to Rev 4
in Firestopping.
---
title: Firestopping
…175 unchanged lines
### The International Building Code requires special inspection of through-penetration firestop systems and fire-resistive joint systems in high-rise buildings and in buildings of certain occupancy classifications. {note}
+### Where special inspection is required by code or by the contract documents, the special inspector shall inspect installations in accordance with ASTM E2174 (through-penetrations) and ASTM E2393 (joints).
+
```datasheet
label: Third-Party Special Inspection Required
…5 unchanged lines
```
−### Where special inspection is required by code or by the contract documents, the special inspector shall inspect installations in accordance with ASTM E2174 (through-penetrations) and ASTM E2393 (joints).
−
### Both standards prescribe a destructive sampling rate (typically a percentage of installations or a minimum number per floor) and a visual inspection of all accessible installations. {note}
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### The F rating is the fire-resistance rating of the through-penetration firestop system, measured as the duration in hours during which the system prevents flame passage and resists hose-stream impact at the conclusion of the fire test under UL 1479 or ASTM E814. {note}
+### The F rating of the installed system shall equal or exceed the fire-resistance rating of the assembly being penetrated.
+
```datasheet
label: Required F Rating
…10 unchanged lines
```
−### The F rating of the installed system shall equal or exceed the fire-resistance rating of the assembly being penetrated.
−
### A two-hour rated wall requires a minimum two-hour F-rated through-penetration system at every penetration. {note}
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### The T rating measures the duration during which the temperature rise on the unexposed side of the firestop system — including the temperature of any penetrating items at a defined distance from the unexposed face of the assembly — remains below 325 °F (163 °C) above ambient. {note}
+### The T rating is a measure of thermal transmission through the penetrant itself, not only through the firestop materials. {note}
+
+### The T rating is required by the International Building Code wherever the penetration is located in a fire-rated floor or floor-ceiling assembly, where combustibles on the floor above could be ignited by heat conducted through the penetrant, and at any penetration where combustible materials are within 1 inch of the unexposed side.
+
+### A T rating equal to the assembly rating is required at floor penetrations; in walls, a zero T rating is typically acceptable where no combustibles are adjacent.
+
```datasheet
label: Required T Rating
…9 unchanged lines
```
−### The T rating is a measure of thermal transmission through the penetrant itself, not only through the firestop materials. {note}
−
−### The T rating is required by the International Building Code wherever the penetration is located in a fire-rated floor or floor-ceiling assembly, where combustibles on the floor above could be ignited by heat conducted through the penetrant, and at any penetration where combustible materials are within 1 inch of the unexposed side.
−
−### A T rating equal to the assembly rating is required at floor penetrations; in walls, a zero T rating is typically acceptable where no combustibles are adjacent.
−
### Metallic pipes and conduits readily conduct heat and therefore reduce the T rating of a firestop system below its F rating. {note}
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### The L rating quantifies the air leakage through the through-penetration firestop system at ambient temperature and at 400 °F (204 °C), expressed in cubic feet per minute per square foot of opening area at a pressure differential of 0.30 inch water column. {note}
+### The L rating is required by the International Building Code at penetrations of smoke barriers and smoke partitions, including the smoke-resistant construction enclosing corridors, exit access stairs, and smoke compartment boundaries in healthcare and other occupancies where smoke containment is a life safety objective.
+
```datasheet
label: L Rating Required (Smoke Barrier)
…7 unchanged lines
```
−### The L rating is required by the International Building Code at penetrations of smoke barriers and smoke partitions, including the smoke-resistant construction enclosing corridors, exit access stairs, and smoke compartment boundaries in healthcare and other occupancies where smoke containment is a life safety objective.
−
### The maximum permitted L rating depends on the application: 5.0 CFM/sq ft at both ambient and 400 °F for most smoke-barrier applications under the IBC.
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### The W rating indicates that the through-penetration firestop system has been tested and listed to resist water leakage at a defined hydrostatic pressure for a defined duration prior to fire testing. {note}
+### A W rating is required at horizontal penetrations through floors in spaces where standing water from fire department hose streams, fire sprinkler discharge, plumbing leaks, or wet construction (such as floors above swimming pools, mechanical penthouses, or kitchens) could pond above the penetration and migrate to the floor below.
+
```datasheet
label: W Rating Required
…7 unchanged lines
```
−### A W rating is required at horizontal penetrations through floors in spaces where standing water from fire department hose streams, fire sprinkler discharge, plumbing leaks, or wet construction (such as floors above swimming pools, mechanical penthouses, or kitchens) could pond above the penetration and migrate to the floor below.
−
### A W rating is recommended at all floor penetrations in healthcare and data center construction.
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### Each major category of penetrant has distinct fire behavior and therefore requires a system designed for that behavior. {note}
+### The penetrant type shall be specified for each penetration so that a firestop system listed for that penetrant category is selected.
+
```datasheet
label: Penetrant Type
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### The annular space is the gap between the penetrant and the edge of the opening through the assembly, and is one of the most important variables in the selection of a listed system. {note}
+### The minimum annular space of the selected listed firestop system shall be specified and verified against field conditions at each penetration.
+
```datasheet
label: Minimum Annular Space (Listed System Range)
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```
+### The maximum annular space of the selected listed firestop system shall be specified and verified against field conditions at each penetration.
+
```datasheet
label: Maximum Annular Space (Listed System Range)
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### Sleeves are used at floor penetrations to provide a finished edge to the opening, to support the penetrant during construction, and to allow the firestop material to be installed flush with the floor surface. {note}
+### Whether a sleeve is used at each floor penetration, and whether it is cast in the slab or grouted in a core-drilled opening, shall be specified.
+
```datasheet
label: Sleeve Used at Floor Penetration
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### Firestop materials fall into several categories defined by their composition and fire-response mechanism. {note}
−### The selection among them is determined by the listed system, not by the Contractor's preference. {note}
+### The selection among them is determined by the listed system, not by the Contractor's preference.
```datasheet
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### The head-of-wall joint is the linear gap between the top of a rated wall and the underside of the floor or roof deck above. {note}
−```datasheet
−label: Head-of-Wall Joint Width (Nominal)
−type: range
−unit: in
−options:
− min: 0.5
− max: 4
− step: 0.25
−default: 1
−```
+### Where the wall is built with a deflection head to accommodate structural movement, the joint shall accommodate the design deflection while maintaining the fire rating and, in the case of smoke barriers, the smoke seal.
```datasheet
…8 unchanged lines
```
−### Where the wall is built with a deflection head to accommodate structural movement, the joint shall accommodate the design deflection while maintaining the fire rating and, in the case of smoke barriers, the smoke seal.
−
### Head-of-wall systems are tested under UL 2079 / ASTM E1966 at a defined joint width and movement class; the installed condition shall be within the tested width and movement range.
+```datasheet
+label: Head-of-Wall Joint Width (Nominal)
+type: range
+unit: in
+options:
+ min: 0.5
+ max: 4
+ step: 0.25
+default: 1
+```
+
### The joint shall be filled per the listed system, which typically includes a backer of mineral wool or backer rod compressed to a defined density, an intumescent or elastomeric sealant cap on the fire-exposed side, and, in two-sided installations, a similar cap on the opposite side.
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### The gap between the edge of a fire-resistance-rated floor and an exterior curtain wall is the "perimeter fire barrier" or "safing slot" condition. {note}
+### The perimeter fire barrier shall be filled with a tested system that prevents fire and smoke from spreading vertically through the gap from one floor to the next.
+
```datasheet
label: Perimeter Fire Barrier System (Curtain Wall Edge)
…6 unchanged lines
```
−### The perimeter fire barrier shall be filled with a tested system that prevents fire and smoke from spreading vertically through the gap from one floor to the next.
−
### Perimeter fire barriers are tested under ASTM E2307 (intermediate-scale multi-story test) in addition to UL 2079. {note}
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### The Contractor shall document any conditions observed during installation that may affect the performance or durability of installed firestop systems and shall bring them to the Architect's attention before completing the work.