Electrical Floor Boxes

What is a floor box, and where is it used?

A floor box is an electrical box set into the floor to deliver power and low-voltage connections where a wall outlet can't reach. You'll find them in open offices, conference tables, retail displays, restaurants, and trade-show floors. The box sits flush with the finished floor under a cover or flip-lid that protects the receptacles between uses.

What's the difference between a poke-through and a cast-in-concrete floor box?

It comes down to the floor it goes in. A cast-in (concrete) box is poured into a new slab before the concrete sets. A poke-through assembly drops into a cored hole in an existing floor and restores the floor's fire rating with an intumescent collar. Use cast-in for new construction, poke-through for retrofits.

How do I choose a floor box for a concrete slab versus a wood floor?

The subfloor sets the box type. A concrete-tight box with adjustable height suits a poured slab, sealing out wet concrete during the pour. A nonmetallic or stamped-steel box drops between joists in a wood or raised access floor. For a finished slab with no chase below, a poke-through is usually the only option.

Can one floor box carry power and low-voltage data together?

Yes — a multi-service floor box splits into isolated compartments, keeping line-voltage power physically separated from data, AV, and telecom to prevent interference. A single cover can present receptacles plus keystone or HDMI ports. Single-service boxes carry power only, when that's all a location needs.

What floor box cover and flange match my finished floor?

Covers are chosen by the floor finish. A carpet flange grips carpet edges, a tile flange recesses to set tile or stone flush, and a wood flange finishes a hardwood floor. The cover itself is either a flush plate, a flip-lid, or a while-in-use bubble for cords. Brass, nickel, and aluminum match the décor.

Are floor boxes rated for foot traffic and spills?

They have to be. Floor boxes and covers are listed for floor use, rated to be walked on, and the covers are scrub-water resistant to survive mopping. A poke-through additionally carries a UL fire rating to keep the floor's rating intact. Match the box to the traffic and exposure the location sees.

Wiring the box itself? The receptacles that mount inside are in Receptacles, the conduit that feeds it is in Conduit Fittings, and every other box type — junction, device, and weatherproof — sits under Electrical Boxes & Covers.