Oatey 38942 Supply Box Square, Plastic Faceplate, 8.25", White

A clean finish around a supply line isn’t glamorous, but it can make the difference between a pro-looking install and a patchwork afterthought. I put Oatey’s square supply box to work on a couple of small projects—a retrofit of an older ice-maker line and a tidy-up around a single shutoff—and came away impressed with its simplicity, coverage, and overall fit and finish, with a few caveats worth noting.

What it is, and what it’s for

This is a recessed supply box with a square, snap-on plastic faceplate. The box itself measures 6 inches by 6 inches with a depth of 3-3/8 inches; the faceplate is 8-1/4 inches square. In plain terms, the box houses one or two small supply connections (think an ice maker shutoff, a 1/2-inch angle stop feeding a toilet or single fixture, or a single outlet for a water filter), while the faceplate covers the drywall cutout and gives you a crisp, finished look. It’s not a laundry box with a drain; it’s smaller and purpose-built for supply-only access.

If you’ve got a ragged opening around a stub-out, a missing trim ring on an older recessed box, or you’re adding an ice maker shutoff and want something cleaner than a surface escutcheon, this is the right category of product.

Build and finish

The unit is made of high-impact polystyrene in white. The plastic is thicker and stiffer than the bargain-bin boxes I’ve used in rental turnovers; it doesn’t flex like a clamshell in your hand. The faceplate has a subtle sheen—not glossy-glossy, but clean enough to blend with bright white trim and appliances. It wipes down easily and resists scuffs better than I expected.

Fit between the face and the box is positive. The engagement tabs line up cleanly and don’t feel like they’ll loosen with repeated removal. I popped the face on and off a dozen times while doing wall touch-ups and valve checks and never felt like I was flirting with a cracked clip.

Sizing and compatibility: measure first

The most important thing to know: the box opening is 6 by 6 inches, and the faceplate is 8-1/4 inches square. That means:

• It’s an excellent match for older small-format supply boxes (common in 1980s ice-maker installs) and new work where you’re running a single shutoff in a tight stud bay.
• It is not sized for standard modern laundry boxes, which are larger and include a drain port. Don’t expect it to cover or replace a laundry trim ring.
• The larger faceplate provides about 1-1/8 inches of coverage beyond the box flange on all sides, which is generous for hiding uneven drywall cuts.

In my retrofit scenario, the box aligned well with an existing 6x6 recess, and the new faceplate completely erased an uneven opening without looking oversized. On a different wall, I tried it as a “rescue trim” over a too-big cutout around a small service valve, but the opening behind it exceeded the 8-1/4-inch faceplate—no dice. Measure the existing box (or your planned cutout) and make sure the faceplate will cover with a bit to spare.

Installation: new work and retrofit

For new work, this installs like any recessed supply box: fasten to a stud using the box’s side ears, set the depth so the front flange is flush with the finished wall, run your supply line and valve, close the wall, and pop on the faceplate. The 3-3/8-inch depth leaves room for a compact quarter-turn valve and a gentle bend in 1/2-inch PEX or copper with an elbow. If you’re feeding a refrigerator line, a combination angle stop with a 1/4-inch compression outlet fits comfortably.

On retrofits, I had two approaches:

• If the existing box is compatible (same 6x6 footprint), the faceplate snaps right on, and you’re done in seconds.
• If I was dressing an opening around a different brand’s box or a plain recess, I used a thin, even bead of paintable caulk along the back edge of the faceplate to lock it in place. On glossy paint or when I needed instant hold, a strip of high-bond double-sided tape warmed slightly with a heat gun set to low worked well. The plastic tolerates gentle heat fine; just keep the gun moving and avoid cooking the wall.

Fasteners weren’t necessary for the faceplate in any of my use cases. If you do add a couple of finish screws, pre-drill to prevent cracking, and avoid overtightening—polystyrene is tough, but it’s still plastic.

In use: access and appearance

Day to day, it does exactly what you want: it hides the rough opening, frames the valve, and gives you tool access without fuss. The faceplate’s square geometry sits straight and symmetrical; if you’re fussy about lines near a backsplash or cabinets, you’ll appreciate the clean perimeter. Because the faceplate removes without prying against paint, it’s friendly for future service—no chipping the wall just to get at a packing nut.

The 8-1/4-inch faceplate size is a sweet spot for coverage without looking comically large, even in tight kitchens. In my test install behind a fridge, it disappeared visually; in a powder room, it looked intentional and finished instead of like a patch job.

Durability and maintenance

High-impact polystyrene is the right choice here. It’s rigid, stable, and light. I’d avoid harsh solvents when cleaning—stick to mild soap or a diluted all-purpose cleaner. UV exposure isn’t a concern indoors, and the white color stayed consistent next to semigloss trim paint. If you do scuff it, a melamine sponge takes marks off without dulling the surface.

The clips that retain the faceplate show no sign of wear after repeated removals, and the flange hasn’t warped under normal indoor humidity swings.

Limitations and things to watch

• Size constraints: Again, this is a 6x6 supply box. If you need room for dual valves or a drain, look at a dedicated laundry box instead.
• Color: It’s white only. If your palette is almond or a warmer off-white, you’ll either repaint the faceplate (scuff, plastic primer, two light coats) or live with the contrast.
• Material: While the plastic is sturdy, it’s not a substitute for a metal access panel in areas prone to impact. In a garage or utility corridor where things get dinged, I’d still choose metal.
• Code and clearance: Check local code for shutoff accessibility and wall cavity firestopping. This box isn’t a fire-rated access solution, and it shouldn’t be relied upon to re-establish any fire barrier.

Value

You’re paying for a clean look, a correct fit in a hard-to-find size, and the convenience of a purpose-built solution. Could you cobble together a trim ring and make it work? Maybe. But by the time you’ve cut, painted, and fought with alignment, the cost difference is a wash. Given the build quality and the made-in-USA manufacturing, the price feels justified for anyone who cares about a neat finish and future service access.

Who it’s best for

• Homeowners or pros tidying up an ice-maker shutoff or single-fixture supply.
• Remodelers repairing or replacing older 6x6 boxes whose trim rings have gone missing.
• Anyone who needs generous faceplate coverage to hide rough drywall without stepping up to an oversized access door.

If your project involves washer supplies and a drain, skip this and spec a laundry box. If you need a universal faceplate for a random opening larger than 8-1/4 inches, look at full access panels instead.

Recommendation

I recommend this Oatey supply box for small-format, supply-only applications where you want a clean, square finish and reliable access. It’s well made, the faceplate coverage is generous without being bulky, and installation—either as a new box or a retrofit face—is straightforward. The key is to measure before you commit: as long as your opening is sized for a 6x6 box and the 8-1/4-inch faceplate will cover the cut, you’ll get a tidy, durable result that looks like it was planned from the start.