Hide Brick Stair Wires (Mortar Joint Track)
To conceal stair-lighting wires along a brick stair, use a listed surface raceway fitted over the mortar-joint line, not a cut or filled joint. First check stair clearances, handrail space, wiring type, and exposure. Then secure the raceway with approved fittings and anchors, keep splices accessible, and confirm the finished route meets local code.
A surface raceway can be a lower-cost, less disruptive option than opening masonry, but it will still project from the wall. The key is to make that projection safe and unobtrusive. I have seen the same planning issue arise repeatedly: a route looks neat on the wall, then proves awkward near a handrail, stair edge, or low ceiling.
A mortar joint is a visual guide, not an electrical pathway. Don’t bury ordinary cable in mortar or assume a joint can be cut without affecting the masonry. The practical goal is a listed, accessible raceway that follows the joint line while protecting the conductors and preserving stair clearances.
Plan the route before choosing a track
A route survey means tracing where the raceway will run and checking what it could affect. Before buying parts, identify the wiring, location, stair dimensions, and likely mounting surface. These checks help determine whether a mortar-joint route is safe and whether a qualified electrician should handle the work.
Write down whether the conductors serve low-voltage lighting or a line-voltage circuit. Note whether the stair is indoors or exposed to weather, where any junction boxes are, and whether the route passes a handrail, door, landing, or ceiling. If you are unsure what kind of cable or circuit is present, don’t guess. Ask a qualified electrician to identify it and confirm the enclosure and wiring requirements.
Measure the stair at the narrowest point and along the full route. Record existing handrail height and clearance, plus the lowest overhead point. A raceway and its fittings add depth, so measure the finished projection, not only the bare track.
Check the adopted local codes before work begins. The National Electrical Code (NEC) covers electrical raceways and wiring; the International Residential Code (IRC) or International Building Code (IBC), as adopted locally, may govern stair dimensions. Editions and local amendments differ. The local authority having jurisdiction (AHJ) can confirm which rules apply and whether a permit or inspection is required.
Choose a listed raceway, not a cut mortar channel
A raceway is a protective enclosure for electrical conductors. For a brick stair, the usual approach is a listed surface-mounted system installed over the wall, aligned with the mortar joint for a cleaner look. The product must be suitable for its location and wiring, with compatible covers, fittings, and supports.
Two common code references are NEC Article 358 for electrical metallic tubing (EMT) and Article 386 for surface metal raceways. These systems are not interchangeable in every situation. The product listing, conductor type, location, and installation method matter. Select a system only after confirming its instructions and code suitability.
| Option | When it may suit the route | Key checks |
|---|---|---|
| Listed surface metal raceway | A neat, surface-mounted path is needed along a wall | Confirm listing, conductor capacity, fittings, and mounting method |
| EMT | A metal conduit route is appropriate and can be installed to its rules | Confirm fittings, supports, conductor fill, and box connections |
| Cable concealed in mortar | Not a suitable shortcut for ordinary wiring | Do not bury cable or an unlisted track in mortar or grout |
A raceway’s capacity is not judged by whether the cover closes. An electrician should confirm conductor fill, wire type, circuit requirements, and whether the system is allowed for the intended wiring. Don’t route a TV power cord or an extension cord inside a track unless the product is specifically listed for that use. A fixed wiring installation may be required instead.
Check stair clearance and handrail space
Clearance is the open space people need to use the stair safely. A raceway that follows a mortar joint can still reduce that space or create a snag point. Check the whole route after accounting for covers, elbows, end fittings, and mounting hardware.
For a typical dwelling stair, the IRC baseline is 36 inches of minimum stairway clear width under Section R311.7.1, and 6 feet 8 inches of minimum headroom under Section R311.7.2. The applicable code and exceptions depend on the building and local adoption. Measure the finished stair, including the raceway’s projection, and ask the building official or qualified professional if a measurement is close.
Where the IRC handrail rule applies, the baseline height is 34 to 38 inches under Section R311.7.8.1. Keep the raceway out of the required graspable handrail area and its clearance. Don’t assume that moving the track slightly toward the wall resolves a conflict; check the actual handrail and stair geometry.
Also inspect for clothing snags, sharp edges, and exposed corners. A track that is technically mounted but catches a sleeve or crowds a handrail is not a good route. If the joint line crosses a clearance problem, choose another route rather than forcing the track to fit.
Install the track without damaging the masonry
A dry fit means temporarily placing raceway sections in position before fastening them. It reveals alignment and clearance problems while changes are still easy. Test a short section first, including a cover and end fitting, then review the full route before drilling.
Trace and mark the route. Follow the mortar-joint line where practical, but check width, headroom, handrail clearance, door swings, and access to boxes. Locate possible hidden services before drilling. Use a suitable method for the wall and consult a professional if the stair or masonry structure is uncertain.
Test the selected system. Confirm the raceway is listed for the location and wiring. Dry-fit sections, bends, covers, and terminations. Check that the assembly is not a snag hazard and does not create a clearance issue. Confirm the manufacturer’s instructions allow the proposed mounting method.
Fasten to the actual substrate. Brick and mortar are different anchoring surfaces. Use fasteners and anchors approved for the substrate and raceway system. Don’t rely on deteriorated mortar for support. Don’t drill blindly into the stair, and don’t cut or rout brick or mortar to recess wiring.
Install wiring and make connections correctly. Follow the adopted NEC and the raceway listing. Splices belong in approved, accessible boxes, not behind a sealed cover or inside the wall without access. A qualified electrician should verify circuit and enclosure requirements, especially for line-voltage work.
Close and inspect the route. Fit listed covers and end fittings. Seal only where the product instructions and location require it. Check cover retention, secure supports, conductor protection, and stair clearances. Arrange required inspection before treating the installation as complete.
For EMT, NEC 358.30 generally requires fastening within 3 feet of each box, cabinet, or termination, with supports no more than 10 feet apart. The code includes stated exceptions, so confirm the adopted edition and installation details. Other raceway systems have their own rules; don’t apply EMT spacing to every track.
Compare routes and practical installation scenarios
A route comparison is a way to weigh appearance against access, clearance, and installation limits. The best choice is not always the most hidden one. A visible, listed raceway can be safer and easier to maintain than a recessed path that damages masonry or leaves wiring inaccessible.
| Route | Visual result | Main concern | Best next step |
|---|---|---|---|
| Surface track centered on a joint | Follows the brick pattern but remains visible | Projection may affect clearance or snag clothing | Mock up the full profile and measure |
| Surface track on a different wall line | May be less aligned with the brick | Could avoid a tight handrail or headroom area | Compare routes before drilling |
| Recessed track or cable in a chased joint | Less visible | Can damage masonry and conceal wiring improperly | Don’t proceed without a designed, code-compliant method |
| Reroute away from the stair | May require a longer run | Requires a suitable path and accessible connections | Ask an electrician to assess options |
Illustrative scenario: narrow stair beside a handrail. A track placed directly on the joint line looks orderly, but its cover projects toward the usable stair space. The installer should measure the finished width and handrail clearance, then test an alternate route. If neither route preserves required clearances, the stair path is not suitable.
Illustrative scenario: crumbly mortar. The mortar looks like an easy fastening line, but it may not hold anchors securely. The right response is not more adhesive or a deeper chase. Verify the substrate and use a mounting method approved for it, or choose a different route.
These are planning examples, not a substitute for inspecting a specific stair. In my field work, checking one complete section with its cover and fittings often exposes the problem sooner than installing a long run and discovering the conflict at the landing.
Common mistakes to avoid
The most serious mistake is treating the joint as a place to hide wire. Mortar does not become a listed raceway because it covers a cable. Cutting a joint can also affect masonry support, and a buried conductor or splice may become inaccessible or unprotected.
Avoid these shortcuts:
- Don’t bury ordinary cable or an unlisted track in mortar, grout, or a chased joint.
- Don’t conceal an inaccessible splice.
- Don’t use adhesive-only or mortar-only attachment unless the raceway manufacturer lists that method for the substrate and installation.
- Don’t drill without checking for existing services and understanding the stair and wall construction.
- Don’t assume a low-voltage label means every cable, power supply, or enclosure can be installed in the same way.
- Don’t leave a cover loose, an edge exposed, or an end fitting missing.
If the route cannot meet clearance rules, reroute it. A clean appearance does not justify narrowing a stair or compromising a handrail.
Final checks before using the stair
A final check means reviewing the installed system as a complete route, not just confirming that the wire is out of sight. Verify the cover is secure, fittings are in place, supports follow the product rules, and conductors are protected. Confirm there are no exposed or inaccessible splices.
Measure the finished clear width and headroom again. Check the handrail area and walk the route carefully to spot edges or snag points. Test the lighting and arrange any required inspection. Keep the product instructions and installation details for future service.
The most reliable result is a listed raceway mounted on the surface, aligned with the brickwork where practical, and kept clear of stair and handrail requirements. If a joint-line route fails any of those checks, use a different route rather than cutting into the masonry.
Frequently asked questions
These quick answers cover the most common decisions about routing stair-lighting conductors beside brickwork. Local code adoption, the raceway listing, and the actual stair layout still control the final installation.
Can I put a wire inside a brick mortar joint?
No. Don’t bury ordinary cable or an unlisted track in mortar or grout. Use a suitable listed raceway or another code-compliant wiring method.
Can I cut a channel into the mortar to make the track flush?
Don’t cut or rout the joint as a shortcut. It may affect masonry support and can leave wiring inaccessible or unprotected.
Is a surface raceway allowed on a stair wall?
It may be allowed if it is listed for the installation and does not violate electrical rules or reduce required stair clearances. Confirm local requirements.
How much stair width must remain?
The IRC baseline for a typical dwelling stair is 36 inches of clear width. Local adoption, building type, and exceptions can change what applies.
What headroom should I check?
The IRC baseline is 6 feet 8 inches. Measure after installing the raceway and fittings, and confirm the local code and any exceptions.
Can the raceway follow the handrail?
Only if it stays out of required handrail space and maintains applicable clearances. Check the actual stair, rail, and finished track projection.
Can I use adhesive to attach the raceway?
Only when the raceway manufacturer lists that method for the substrate and installation. Otherwise, use approved fasteners and anchors for the actual masonry.
How often does EMT need support?
NEC 358.30 generally requires support within 3 feet of boxes or terminations and at intervals no greater than 10 feet, subject to code exceptions.
Can I hide an extension cord in the track?
Not unless the raceway is specifically listed for that use. Have an electrician verify the correct wiring method for the circuit and equipment.
Who should verify the installation?
A qualified electrician can check the circuit, raceway, conductors, and connections. The local authority having jurisdiction can confirm permits, inspections, and adopted code requirements.
(This article was written by one of our staff writers, Michael Holloway. Visit our Meet the Team page.)
