When installing electrical conduit on walls or ceilings, a surface mount backbox or box with knockouts can simplify wiring in tight spaces. This guide highlights five reliable options that fit common surface raceway systems, weatherproof needs, and indoor/outdoor applications. Each product features easy mounting, practical knockouts, and sturdy construction to help protect wiring and devices.
| Product | Brand | Key Feature |
|---|---|---|
| Leviton Surface Mount Backbox, 1-Gang | Leviton | Breakouts match surface raceway systems |
| Sigma Engineered Solutions 14250 | Sigma Engineered Solutions | Weatherproof, 3 knockouts |
| Sigma Engineered Solutions 14250WH | Sigma Electric | Weatherproof, 3 knockouts, white |
| Sigma ProConnex EMT/Rigid Conduit Hanger | Sigma Engineered Solutions | Conduit hanger for EMT/rigid |
| Sigma Electric 14251BR | Sigma Electric | Four 1/2″ knockouts, 18.3 cu in |
Leviton Surface Mount Backbox, 1-Gang, 42777-1WB
Leviton’s Surface Mount Backbox is designed for installations where wall boxes aren’t practical. It features breakouts to align with common surface mount raceway systems, and the white box has a depth of 1.45 inches. The unit supports convenient mounting in constrained spaces and helps keep wiring organized and protected against moisture and dust in suitable environments.
Leviton Surface Mount Backbox, 1-Gang, 42777-1GB
The grey version from Leviton mirrors the same surface mount functionality with a 1.45-inch depth. It offers breakouts for surface raceway compatibility and is suitable for indoor or sheltered outdoor use where a wall box is not feasible. This backbox helps protect connections while maintaining a clean finish.
Sigma Engineered Solutions 14250
Weatherproof protections make the Sigma 14250 suitable for outdoor use, with outdoor-grade protection for in-use plugs and outlets. The 1-Gang box accommodates three 1/2-inch knockouts and offers 18.3 cubic inches of internal space. It includes a pre-installed ground screw and mounting hardware, enabling flexible orientation (vertical or horizontal) during installation.
Sigma Engineered Solutions 14250WH White
The 14250WH white variant preserves weatherproof protection with the same practical features as the gray model. It’s designed for weather-resistant installations, offering three 1/2-inch knockouts, ample space, and an easy mounting process. Pre-installed components ensure quick setup and reliable performance in exposed environments.
Sigma ProConnex EMT/Rigid Conduit Hanger #2
ProConnex conduit hanger anchors rigid or EMT conduit, sized for 1-inch trade—compatible with similar conduit sizes. Pre-assembled with a carriage bolt and nut, this hanger offers a sturdy mounting solution for secure conduit support, streamlining the installation process and reducing the risk of movement or stress on connections.
Sigma Electric 14251BR 1/2-Inch 4-Hole 1-Gang Box
With four 1/2-inch knockouts and 18.3 cubic inches of capacity, this Sigma Electric 1-Gang box serves as a versatile junction point for conduits or to house a receptacle or switch. It ships with a pre-installed ground screw, closure plugs, mounting lugs, and two self-tapping screws, supporting straightforward vertical or horizontal installation.
Buying Guide — Surface Mount Conduit and Backboxes
Key considerations help ensure you choose the right surface mount solution for your project:
- Application environment: Indoor, sheltered outdoor, or fully outdoor. Weatherproof models are essential for exterior use or damp locations.
- Box capacity and knockouts: Confirm cubic inches and the number/size of knockouts to accommodate planned conduits and devices.
- Material and durability: Metal boxes resist impact and provide grounding integrity; corrosion-resistant finishes are important in harsh environments.
- Mounting orientation and accessibility: Vertical or horizontal mounting options influence device placement and wiring routes.
- Compatibility with raceways: Ensure box breakouts align with your surface raceway system for a clean, secure fit.
- Grounding and accessories: Pre-installed ground screws and included lugs can simplify mounting and improve safety.
- Weather protection vs. accessibility: Weatherproof products may require additional seals or plugs for in-use devices.
When comparing products, weigh installation ease against environmental protection. For outdoor or wet locations, prioritize weatherproof ratings and robust gaskets. For indoor use, consider whether a smaller backbox with fewer knockouts meets your wiring needs while keeping access simple for maintenance. Evaluate whether a single-gang configuration will accommodate a receptacle or switch or if a larger box is needed for future expansions. Finally, verify compatibility with your existing conduit and raceway components to minimize mismatches and labor during installation.