Corpus sync: neutrality remakes, note hygiene, datasheet relocation, transformer-split cross-refs
---
title: Floor Boxes and Poke-Through Devices
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# Quality Assurance {toc}
−## Floor boxes must be listed specifically for floor installation, not merely as general outlet boxes. {note}
+## Floor boxes must be listed specifically for floor installation, not merely as general outlet boxes.
## A box that is merely listed as a general outlet box does not satisfy NEC 314.27(C); the floor-specific listing covers the crush load, moisture exposure, and cover-operation conditions unique to in-floor service. The clauses below carry the obligations. {note}
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## A preset box must be located before the pour and cannot move afterward; an adjustable box tolerates finish-elevation variation; a poke-through is installed last by core-drilling a finished slab and is the only option for retrofit into an existing slab. The selection below drives the rest of the configuration. {note}
+## The floor box type shall be specified for each location based on whether it is set before the pour, adjustable after the pour, or a poke-through into an existing slab.
+
```datasheet
label: Floor Box Type
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```
−## The service-head style shall be specified explicitly because installer defaults vary by region. {note}
+## The service-head style shall be specified explicitly because installer defaults vary by region.
## A surface-style service head sits above the slab; a fully recessed (flush) assembly keeps the device below the finish-floor plane. Leaving this unstated risks an above-floor service head where a flush finish was required. {note}
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## Power provisions are specified by receptacle rating, count, and GFCI requirement. {note}
−## The 80%-case commercial-office receptacle is a 20A, 125V, NEMA 5-20R duplex; 20A, 250V (NEMA 6-20R) is used for audiovisual or equipment circuits when required. Receptacle count per housing is typically two or four duplexes. {note}
+## The usual commercial-office receptacle is a 20A, 125V, NEMA 5-20R duplex; 20A, 250V (NEMA 6-20R) is used for audiovisual or equipment circuits when required. Receptacle count per housing is typically two or four duplexes. {note}
### Each power receptacle shall be a 20A device rated for the system voltage, with conductor terminations rated for 60°C or 75°C in accordance with NEC 110.14(C).
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### The fire rating of the poke-through device shall match the UL Fire Resistance Directory assembly design number for the specific floor-ceiling assembly in which it is installed.
−### A fire-rated poke-through device shall not exceed 325°F (163°C) temperature rise on the unexposed face under the UL CEYY classification fire test.
−
−### Fire-rated poke-through devices shall be provided with the intumescent collar or firestop components required by the device classification.
−
−## The fire-rating selection is dictated by the floor-ceiling assembly's documented hourly rating, never an assumption. {note}
−
−## The 2-hour rating is the 80% case for a typical office floor-ceiling assembly, but the value is dictated by the assembly the structural and architectural documents specify, not by convention. {note}
−
```datasheet
label: Poke-Through Fire Rating
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```
+### A fire-rated poke-through device shall not exceed 325°F (163°C) temperature rise on the unexposed face under the UL CEYY classification fire test.
+
+### Fire-rated poke-through devices shall be provided with the intumescent collar or firestop components required by the device classification.
+
+## The fire-rating selection is dictated by the floor-ceiling assembly's documented hourly rating, never an assumption. {note}
+
+## The 2-hour rating is the most common rating for a typical office floor-ceiling assembly, but the value is dictated by the assembly the structural and architectural documents specify, not by convention. {note}
+
## Core-drill diameter is selected for the service density of the device. {note}
−## A 4-inch nominal core is the default for standard single- and dual-service poke-throughs in open offices; 6-inch serves heavy multi-service devices; 10-inch serves large conference and audiovisual assemblies. The core diameter shall be coordinated with the device's installation instructions. {note}
+## A 4-inch nominal core is the default for standard single- and dual-service poke-throughs in open offices; 6-inch serves heavy multi-service devices; 10-inch serves large conference and audiovisual assemblies. The core diameter shall be coordinated with the device's installation instructions.
### The core-drill diameter shall match the manufacturer's installation instructions for the selected device and its tolerance.
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# Box Fill and Raceway Entry {toc}
−## Box fill shall be calculated for every floor box so the conductor count does not exceed the listed box volume. {note}
+## Box fill shall be calculated for every floor box so the conductor count does not exceed the listed box volume.
## Box volume and conductor fill are governed by NEC Article 314 and Chapter 9, Table 1. The raceway feeding the box is specified in [[sync/raceways-and-conduit]]; this section sets only the hub provisions and the fill obligation at the box itself. {note}
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# Performance Ratings {toc}
−## The cover crush-load rating shall meet or exceed the anticipated floor loading. {note}
+## The cover crush-load rating shall meet or exceed the anticipated floor loading.
## The minimum crush-load rating under the device listing is 300 lbs; premium models are rated to 1,000 lbs. Select the rating to suit the traffic and rolling loads anticipated at the location. {note}
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### The fire rating of the floor-ceiling assembly shall be confirmed with the AHJ and the Structural Engineer of Record before poke-through device selection.
−## Pour-in-place boxes shall be set to the correct elevation and secured against displacement during concrete placement. {note}
+## Pour-in-place boxes shall be set to the correct elevation and secured against displacement during concrete placement.
−## A preset box set too low is buried by screeding; set too high it becomes a trip hazard and a finish defect. Elevation and floor-finish tolerance shall be coordinated with the concrete trade. {note}
+## A preset box set too low is buried by screeding; set too high it becomes a trip hazard and a finish defect. Elevation and floor-finish tolerance shall be coordinated with the concrete trade.
### Pour-in-place boxes shall be set to the finished-slab elevation coordinated with the concrete subcontractor, accounting for slab thickness and finish tolerance.
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### Core-drill locations in post-tensioned decks shall be installed as shown on the coordinated structural penetration plan [[drawing: PT penetration plan]].
−## Devices shall be installed plumb, flush, and aligned with the finished-floor plane. {note}
+## Devices shall be installed plumb, flush, and aligned with the finished-floor plane.
### Recessed covers shall be set flush with the finished floor within the manufacturer's tolerance, with no lip exceeding the ADA §302 surface-discontinuity limit.
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# Testing {toc}
−## Each installed device shall be tested for grounding, polarity, and GFCI function before substantial completion. {note}
+## Each installed device shall be tested for grounding, polarity, and GFCI function before substantial completion.
### Each power receptacle shall be tested for correct polarity and grounding continuity.
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# Warranty {toc}
−## The Contractor shall provide the manufacturer's standard written warranty for floor boxes, poke-through devices, covers, and service fittings. {note}
+## The Contractor shall provide the manufacturer's standard written warranty for floor boxes, poke-through devices, covers, and service fittings.
### The Contractor shall warrant that floor boxes, poke-through devices, covers, and fittings are free from defects in material and workmanship for a period of not less than one year from the date of Substantial Completion.
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# Spare Parts {toc}
−## The Contractor shall furnish spare covers, inserts, and gaskets to support future maintenance. {note}
+## The Contractor shall furnish spare covers, inserts, and gaskets to support future maintenance.
### The Contractor shall furnish not fewer than two spare covers of each type and finish installed on the project.
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- Spare modular inserts
```