Field Notes
Floor box sleeve bonding and slab pour protection record
Before slab placement, the floor box record should show the approved box or sleeve, layout location, elevation, conduit entries, knockout plugs, bonding jumper or grounding basis, divider status, temporary cover, debris protection, exceptions, and release decision.
Direct answer
Before slab placement covers a floor box, pour sleeve, or floor outlet rough-in, the record should identify the area, grid, room, box tag, device type, approved submittal, slab type, finished-floor basis, box or sleeve elevation, orientation, conduit entry, conduit trade size, unused knockout or hub plugs, low-voltage divider status, bonding jumper or grounding basis, ground pigtail status where required, cover or pour cap, screw and gasket status where applicable, rebar or form attachment, conflicts, debris protection, water protection, inspection witness, exceptions, correction owner, and release decision.
The point is to prove that the box was not buried with the wrong product, wrong height, open knockout, missing divider, unclear grounding path, loose cover, blocked conduit, concrete-entry path, or unapproved location. A useful record lets the electrician, concrete crew, inspector, and owner see exactly what was released before the pour.
Use this as documentation guidance only. The electrical drawings, approved submittal, product installation instructions, listing, NEC and local code requirements, engineer, inspector, concrete placement plan, post-tension or reinforcing layout, and qualified electrical contractor control the actual box selection, bonding, grounding, conduit, cover, fire rating, wet-location suitability, and slab-placement release.
Why pre-pour records matter
Floor boxes are hard to fix after concrete placement. A wrong elevation, missing cover, open hub, damaged conduit, or unrecorded exception can turn into chipping, patching, water intrusion, failed trim-out, or an electrical inspection dispute.
Legrand, Leviton, CANTEX, Hubbell, RACO, UL, and Carlon sources all point to the same field lesson: floor boxes depend on product-specific instructions, listing, conduit entries, knockouts or hubs, protective covers, dividers, grounding or bonding details, and finish-floor coordination.
The weak record says floor boxes in place. The strong record shows each box, sleeve, conduit, plug, bonding detail, temporary cover, elevation, orientation, conflict, correction, and exact slab area released.
Define the slab and box boundary
Start with the drawing location, grid, room, pour strip, slab area, box tag, floor finish, slab thickness basis, formwork, rebar or post-tension zone, and whether the record releases one box, a group of boxes, a sleeve-only rough-in, or a full room.
Do not use a generic photo of the pour area as release evidence. The record should tie each box or sleeve to a plan tag and show how it sits relative to grid lines, walls, columns, furniture feeds, sawcut joints, sleeves, blockouts, and slab edges.
If the box location is held for layout, furniture, low-voltage, AV, post-tension, or owner review, name the hold and keep it out of the slab release list.
Verify the product and approved use
Photograph the floor box label, package label, submittal page, model number, cover family, divider kit, accessory kit, and any on-grade, above-grade, bare concrete, carpet, tile, terrazzo, fire-rated, or scrub-water requirement that affects the installation.
Legrand and Leviton product sources show that floor box families vary by concrete condition, finish floor, cover type, and accessory requirements. The record should prove that the product installed matches the approved use rather than assuming every box accepts every finish.
If a product, cover, leveling ring, concrete adapter, divider, conduit hub, or trim kit is missing or substituted, hold the release or record the approved substitution.
Photograph elevation and orientation
Record the box or sleeve height before concrete. Include elevation screws, leveling cover, temporary concrete cover, pour cap, form attachment, finished-floor allowance, and the orientation of power, data, AV, or furniture-feed compartments.
Leviton instructions and ordering guidance discuss protective covers, leveling features, and concrete-pour protection. Legrand and Hubbell sources also emphasize concrete-floor product families and pre-pour adjustment. The photo record should show the actual height and orientation, not only the product type.
Use a ruler, laser, string line, finished-floor mark, or elevation reference when the inspector or superintendent requires it. If final adjustment is planned after pour, record what is intentionally left proud, low, capped, or adjustable.
Record conduit entries and knockout plugs
Show every conduit entry before placement. Photograph conduit type, trade size, hub, adapter, locknut or fitting where visible, conduit support, bend, entry angle, and compartment served.
Record unused knockout, membrane, reducer bushing, hub, or sleeve plug status. CANTEX and Carlon floor-box instructions both emphasize unused openings, pour covers, plugs, and keeping concrete out of the box. Wiremold instructions show pre-pour knockout and conduit-connection steps.
An open knockout or uncapped hub is a hold point. The record should name the specific side or compartment, correction owner, and retest photo before the pour is released.
Document bonding and grounding basis
Record the grounding path exactly as the project requires. That may include metallic raceway continuity, a factory ground pigtail, an equipment grounding conductor, a listed floor-box grounding method, a separate bonding jumper, a cover grounding lead, or a product-specific exception.
RACO training material discusses floor-box ground continuity and equipment bonding jumper context. Hubbell installation material reviewed for this package includes a separate grounding wire note for nonmetallic conduit systems. UL guidance addresses grounding and bonding concerns around concentric and eccentric knockouts. The record should preserve the basis instead of guessing later.
If the product is nonmetallic, the cover is metallic, the conduit is nonmetallic, the knockouts are concentric or eccentric, or the device grounding method depends on listing, document the manufacturer instruction and inspector-approved basis.
Protect dividers, covers, and devices
Photograph low-voltage dividers, tunnel blocks, internal brackets, receptacle brackets, device plates, temporary covers, pour caps, protective plastic covers, screws, gaskets, and stored components before concrete placement.
Several product instructions call for protective covers, pour caps, or temporary storage of components until concrete is set or trim-out is ready. The record should show that loose parts will not float, get buried, or become contaminated during placement.
If a cover is cracked, screw holes are stripped, a gasket is missing, an internal divider is loose, or device parts are sitting unprotected in the box, hold the release until the condition is corrected.
Coordinate with concrete and reinforcing
The pre-pour record should show rebar, welded wire, post-tension tendons, sleeves, blockouts, embeds, vapor retarder, form edge, sawcut layout, slab joints, and concrete access around the floor box where those items affect the release.
Do not let the electrical record ignore concrete placement risk. A floor box can be correct electrically and still be displaced by pump hose movement, foot traffic, vibration, rebar conflict, tendon conflict, or cover damage during finishing.
If the concrete team must protect a box during placement, name the protection method, monitoring owner, and what is not allowed: stepping on cover, removing cap, pushing conduit, cutting tie wire, or burying parts.
Inspection table
Use a compact table so the electrical, low-voltage, concrete, inspection, and owner teams review the same pre-pour evidence.
| Record field | What to capture | Why it matters |
|---|---|---|
| Box identity | Room, grid, tag, product, submittal, floor finish, slab area | Ties the photo to the approved location and product |
| Elevation | Cover height, leveling screws, finish-floor basis, reference mark | Prevents buried, proud, or unusable trim-out |
| Orientation | Power, data, AV, furniture feed, traffic direction, cover swing | Keeps compartments aligned with the planned use |
| Conduit entries | Trade size, fitting, hub, adapter, support, compartment served | Shows the raceway path before concrete hides it |
| Knockout plugs | Unused hub, knockout, membrane, reducer, plug, cap, seal | Stops concrete, debris, and water from entering the box |
| Bonding basis | Pigtail, jumper, raceway, cover lead, listing, inspector note | Preserves grounding continuity evidence |
| Cover protection | Pour cap, temporary cover, screws, gasket, taped edges, parts storage | Protects the box during placement and finishing |
| Release decision | Exceptions, correction owner, retest photo, slab area released | Defines exactly what can be poured |
Before-slab checklist
Run this checklist before the floor box or sleeve is covered by concrete placement.
- Box or sleeve tag, room, grid, slab area, and approved submittal are identified.
- Product, cover family, trim kit, divider kit, and finish-floor basis match the release scope.
- Box elevation, leveling screws, temporary cover, and orientation are photographed.
- Every conduit entry is photographed with fitting, compartment, support, and routing context.
- Unused knockouts, hubs, membranes, reducer openings, and sleeves are plugged or otherwise protected as required.
- Bonding jumper, ground pigtail, raceway continuity, cover grounding lead, or listed grounding basis is documented.
- Low-voltage dividers, tunnel blocks, internal brackets, and device components are protected or stored as required.
- Temporary cover, pour cap, screws, gasket, tape, and debris protection are in place.
- Rebar, post-tension, vapor retarder, slab joint, and concrete placement conflicts are listed.
- Exceptions, correction owner, retest photos, inspector witness, and release decision are recorded.
Weak versus strong record
Weak record: Floor boxes installed. Ready for pour.
Strong record: Floor boxes FB-2A through FB-2F in Conference 214 were reviewed before Level 2 slab placement. Photos show each Leviton concrete floor box at the approved furniture-feed layout, with top cover set to the finish-floor reference mark, power compartment facing grid B, low-voltage divider installed, conduit entries serving the correct compartments, and unused hubs capped. The temporary protective covers were screwed down, bullseye levels visible, and the boxes were tied to form bracing so pump hose movement would not rotate them.
The grounding basis was documented from the approved submittal and inspector note E-214-7. Photos show the equipment grounding conductor and pigtail at each metallic cover location, plus an exception for FB-2D where the low-voltage conduit adapter was missing a plug. The electrician installed the plug, cleaned the box, reinstalled the cover, and added a retest photo before the concrete foreman released the pour strip. FB-2A through FB-2F were released for slab placement only; final device installation and cover trim remained held for after floor finish.
Common mistakes
The most common mistake is photographing the top of the cover without showing the box tag, conduit entries, unused knockouts, and bonding basis. That leaves the hidden risk undocumented.
Another mistake is assuming the product's floor-box listing solves every grounding and cover condition. Metallic raceway, nonmetallic raceway, cover leads, ground pigtails, device straps, and listed continuity details can differ by product and project.
Other mistakes include wrong finish-floor allowance, missing low-voltage divider, open conduit hub, loose pour cap, box rotated toward the wrong furniture feed, rebar conflict, unprotected device parts, no retest photo after correction, and no exact slab area released.
When to hold slab placement
Hold placement if the box product is not approved, the box elevation is unresolved, the cover or pour cap is missing, concrete can enter the box, an unused knockout or hub is open, conduit is not supported, a divider is missing, or the box is not tied to the layout.
Also hold if the bonding or grounding basis is unclear, the inspector has not accepted a product-specific grounding method, a metallic cover lead is missing where required, a conduit adapter is damaged, rebar or post-tension conflicts are unresolved, or the concrete team cannot protect the box during placement.
A hold should name the box tag, room, grid, issue, correction owner, retest photo requirement, inspector or engineer contact, and whether the whole slab area or only one box is held.
Owner handoff
The handoff should include box layout photos, product labels, approved submittal reference, elevation photos, conduit-entry photos, plug photos, bonding evidence, cover protection photos, conflict notes, exception corrections, retest photos, and release decision.
Store the packet with electrical rough-in inspections, slab pre-pour checklists, low-voltage coordination notes, concrete pour records, post-tension signoffs, floor finish files, and owner punchlist records.
Make the record searchable by box tag, room, grid, slab pour, conduit homerun, and date so a future trim-out or coring issue can be compared to the pre-pour baseline.
Questions before release
Is this the approved floor box or sleeve for the slab, finish, cover, and use? Is it at the right location, orientation, and height? Are all conduits and unused openings accounted for?
What is the grounding and bonding basis? Are the divider, cover, pour cap, plugs, screws, gaskets, and stored parts protected? What rebar, tendon, joint, or concrete placement risks remain?
Answer those questions before the concrete placement covers the evidence.
Compliance and safety limits
This article does not interpret the NEC, select floor boxes, approve grounding methods, set fire ratings, approve wet-location use, design low-voltage separation, authorize slab penetrations, or replace manufacturer instructions. It is a record structure for preserving pre-pour floor-box, sleeve, knockout, bonding, cover, and release evidence.
The approved drawings, product listing, manufacturer instructions, electrical engineer, inspector, local code requirements, concrete placement plan, reinforcing drawings, post-tension procedures, and qualified electrical contractor control the work. If those documents conflict with this checklist, use the controlling document and record the decision.
Do not energize, bond, ground, cut, drill, relocate, remove covers, modify boxes, disturb reinforcing, enter post-tension zones, or release concrete placement outside the qualified team's authority and approved procedures.
Sources checked
- Legrand, Resource RFB Series Four Gang Floor BoxUsed for concrete floor-box family, product use, covers, knockouts, floor-finish compatibility, and adapter-ring context.
- Wiremold Legrand, RFB Series Floor Boxes Installation InstructionsUsed for before-concrete-pour steps, conduit layout, knockout removal, conduit attachment, and component protection context.
- Leviton, Concrete Floor BoxesUsed for concrete floor-box product family, protective cover, leveling, floor-finish, and conduit-entry context.
- Leviton, Concrete Floor Box Systems Installation SheetUsed for protective cover, elevation screws, bullseye level, concrete pour, rebar securing slots, and finish-floor context.
- Leviton, Pop-Up Receptacle Floor Box Instruction SheetUsed for concrete box placement, protective plastic cover, blocking open holes, conduit, wire length, and post-pour trim context.
- Leviton, Floor Box Ordering GuideUsed for protective cover, elevation screws, floor finishes, low-voltage divider, concrete box accessories, and cover family context.
- CANTEX, Floor Box Installation GuideUsed for reducer bushings, unused hub protection, pour cover, concrete form attachment, and grounding pigtail for metal covers.
- Hubbell, SystemOne Recessed Floor BoxesUsed for concrete floor-box systems, pre-pour adjustment, ground pigtails, knockouts, on-grade coating, and UL-related product context.
- Two Gang Recessed Shallow Floor Box Installation InstructionsUsed for temporary concrete cover, leveling screws, concrete pour height, conduit connections, and grounding wire context.
- Hubbell Wiring Device-Kellems, Floor Boxes CatalogUsed for floor-box cover, concrete installation, dimensions, adapter system, and finish-floor coordination context.
- RACO, Floor Boxes Training ModuleUsed for floor-box listing, ground continuity, equipment bonding jumper context, and floor outlet training context.
- UL, Grounding and Bonding with Concentric and Eccentric KnockoutsUsed for grounding and bonding concerns around concentric and eccentric knockouts and equipment grounding continuity context.
- Carlon, Round Non-Metallic Floor Box Installation TrainingUsed for nonmetallic floor box installation in cement, plastic cap, conduit outlets, plugs, and cover instructions context.