Best Electrical Boxes for Concrete Walls and Retrofit Installations
Answering your search for sturdy, reliable electrical boxes for concrete walls: choose options designed to endure masonry surfaces, resist moisture, and fit your remodeling or new-construction project. The top picks below cover concrete floor boxes, old-work retrofit boxes, surface-mount backboxes, and retrofit wall boxes. They’re best for contractors and DIYers tackling concrete or masonry installations, remodels, or upgrades where wall integrity and safety matter most. The following summary highlights who each product is best for and why.
| Product | Best For | Key Strength | Limitations |
|---|---|---|---|
| ARLINGTON FLBC4500 | New concrete floors or slab installations | Low voltage divider and mud cover for concrete floors | Plastic construction may be less rugged than metal in some environments |
| XGGYA Old Work Box | Adding outlets to existing walls | Old-work design with built-in fixing ears | Compact depth may limit some high‑volume wiring |
| Leviton Surface Mount Backbox | Surface-mount installations or nonstandard wall setups | Breakouts to match raceway systems | Shallow depth; not for deep wall recesses |
| Newhouse Hardware 1-Gang Old Work Box | Remodels and renovations on interior walls | Versatile use as junction, switch, GFCI, or duplex box | Plastic construction; may not suit heavy-use outdoor spaces |
| SmarToggle Retrofit Wall Box | Stud or no-stud walls for smart devices | Retrofit design with secure toggles and multiple ports | Specialty product; ensure compatibility with planned devices |
ARLINGTON FLBC4500 Concrete Floor Box
The Arlington FLBC4500 is designed specifically for concrete floors. It features a low-voltage divider and mud cover to keep wiring neat while bedding into a new concrete installation. Best for contractors or homeowners installing floor outlets in new concrete slabs where a dedicated floor box is required. The plastic construction keeps weight manageable, but users should factor in plan for environments that demand higher impact resistance. This box is best for new concrete projects where a floor-mounted outlet or low-voltage assembly is needed.
XGGYA Old Work Box
The XGGYA Old Work Box is a plastic junction box designed for adding new outlets to existing walls. Its built-in fixing ears and rotatable buckle help prevent sagging or detachment, making installation in walls easier. It’s a practical choice for remodeling projects where a traditional wall box would be difficult to reach behind finished surfaces. Best for DIYers updating rooms with new switches or outlets, especially when wall depth and stud location complicate installation. A potential limitation is its relatively compact capacity for multiple conductors or larger devices.
Leviton Surface Mount Backbox, White
The Leviton Surface Mount Backbox is ideal for scenarios where wall boxes aren’t practical, such as behind surface-mounted raceways. It supports breakouts to align with common surface raceway systems and has a shallow depth of 1.89 inches, which is helpful in spaces with limited recessed depth. Best for retrofitting or adding outlets where wall recess is not feasible. Choose this if you’re running conduit or raceways on the surface rather than embedding in drywall.
BELL PSB37550GY Weatherproof Box
The BELL PSB37550GY is a weatherproof single-gang box with three 1/2 inch or 3/4 inch outlets. Constructed from durable PVC, it is designed for outdoor or moisture-prone environments and includes closure plugs and reducer bushings. Best for exterior outlets or garages where weather resistance is key. Limitations include a focus on weatherproofing rather than interior wall use, so consider enclosure needs before selecting this box for indoor projects.
Newhouse Hardware 1-Gang PVC Old Work Box
The Newhouse Hardware 1-Gang PVC Old Work Box is designed for remodeling and renovation work. It fits various applications, including standard switches, GFCI, or duplex receptacles, and is compatible with non-metallic cable. Best for interior renovations where a lightweight, versatile PVC box is advantageous. A limitation is that it’s plastic and may not be ideal for high-stress outdoor applications or environments requiring metal boxes for added durability.
SmarToggle Single Gang Retrofit Wall Box
The SmarToggle Retrofit Wall Box is designed for stud or no-stud installations, making it a strong option for remodeling and smart-device upgrades. It uses 1-1/2 inch toggles for secure mounting and offers four wiring ports for multiple conductors. Best for upgrades to modern outlets or switches in existing walls. It’s a specialized product, so ensure compatibility with the planned smart device and the existing stud layout before choosing.
Buying Guide
What to consider when choosing an electrical box for concrete walls and retrofit projects:
- Wall type and install method: Choose concrete-floor boxes for slabs, old-work boxes for retrofit walls, and surface-mount backboxes when you cannot recess the box.
- Box material: Plastic boxes are lightweight and budget-friendly; metal boxes offer greater durability and protection in demanding environments.
- Depth and capacity: Check the available clearance behind the wall and the number of conductors you need to run. Deeper boxes support more wiring and devices.
- Weather and moisture: For exterior or damp locations, select weatherproof or outdoor-rated boxes to prevent moisture ingress.
- Compliance and compatibility: Ensure boxes match local codes and are compatible with the intended switches, outlets, and devices.
Frequently Asked Questions
- What is the difference between a floor box and a wall box for concrete installations?
Answer: A floor box sits in or on concrete floors to provide outlets or low-voltage connections, while a wall box is installed into the wall or surface to hold switches or outlets. Choose based on whether access is from the floor or wall surface is more practical. - Can I use a standard plastic box in a wet location?
Answer: For wet or outdoor locations, use weatherproof or moisture-rated boxes designed to resist water ingress and corrosion. - Do I need a metal box for concrete walls?
Answer: Not always. Plastic boxes work well for many retrofit and indoor concrete installations, while metal boxes offer higher durability in some environments. - How many conductors can fit in an Old Work Box?
Answer: It varies by model; always check the product’s listed capacity and plan for wire management to avoid crowding. - Are surface mount boxes easier to install than recessed boxes?
Answer: Surface-mount boxes are often easier when you cannot access the interior wall cavity, but may require running raceways for wiring protection.