Hide CCTV & LAN Wires (Smurf Tube Conduits)
To conceal CCTV and LAN cables in Smurf Tube, use listed electrical nonmetallic tubing (ENT) with compatible fittings, size it for the actual cable bundle, and keep it separate from power wiring unless code permits otherwise. Plan accessible pull points, protect cable bends, support the tube correctly, and confirm local code and firestop requirements before closing a wall.
A camera cable that disappears into a wall still needs a safe, serviceable route. The hard part is not only hiding the wire; it is choosing a path that allows future replacement without crowding the tube or crossing a power circuit improperly. I plan the route first, then select the tube and fittings to suit it.
Plan the concealed cable route
A concealed route is the complete path from each camera or network outlet to the recorder, switch, or router. Planning it before drilling helps avoid framing, plumbing, electrical wiring, fire-rated barriers, and spaces with special air-handling rules. It also reveals where you will need access for pulling and future repairs.
Start by tracing each cable’s path on the surface, then mark the proposed route inside the wall or ceiling. Identify the device location, the destination, framing members, electrical boxes and wiring, plumbing, and any fire-rated assemblies. A wall cavity is not automatically an acceptable place for every wiring method.
Decide how many cables the path must carry now and whether you may add more later. CCTV may use Ethernet, coaxial cable, or both, depending on the system. LAN runs may need to serve access points or other network devices. Include the planned cables in the tube sizing calculation rather than assuming a nominal tube size will fit.
Smurf Tube is a common name for flexible ENT, or electrical nonmetallic tubing. Use ENT that is listed for the intended location, along with compatible listed fittings, and follow the product instructions. NEC Article 362 sets rules and limits for ENT; the adopted code edition and local amendments may differ.
Before work, check which NEC edition your local authority having jurisdiction (AHJ) has adopted. Article 800 covers communications circuits, and Article 725 may apply to some Class 2 or Class 3 circuits. Confirm the proposed wiring method with the AHJ when the route or space is unusual.
Confirm access, separation, and clearances
Access means being able to reach the tube ends and any pull points after the wall is finished. Separation means keeping communications wiring apart from power wiring as the applicable rules require. Clearances include safe drilling distances, bend space, and any conditions set by the wall or ceiling assembly.
Plan an accessible opening at both ends of the route. Long runs or routes with several bends may need an approved, accessible pull point to make installation practical. Do not leave a splice or pull point hidden behind finished construction where it cannot be reached.
Where NEC 800.133(A)(2) applies, communications wiring generally needs 2 inches of separation from power conductors unless a stated exception or permitted arrangement applies. Do not put communications cable and power conductors in the same raceway or enclosure unless the applicable NEC rules expressly allow it. If the route must cross power wiring, check the code requirements and local interpretation rather than guessing.
When drilling a framing member, check the hole location against structural rules and existing services. NEC 300.4(A)(1) sets a 1¼-inch setback from the framing-member face for certain wiring. If that setback cannot be met, the required protection plate is steel at least 1/16 inch thick, or choose another compliant route. A plate does not make every hole location acceptable; check structural limits too.
Treat environmental-air spaces with special care. A ceiling cavity used to move environmental air is not an ordinary concealed space. NEC 300.22 and the listings for the cable and raceway can limit what is allowed there. Do not assume standard ENT or ordinary cable is permitted; ask the AHJ to confirm the proposed method.
Size and install ENT
ENT is flexible raceway that protects and routes cable inside the limits of its listing. Correct sizing leaves room for the planned cable bundle and pulling. Correct installation also means using compatible fittings, supporting the tube at required intervals, and avoiding damage at bends and penetrations.
Use NEC Chapter 9, Table 1, along with the applicable raceway and conductor tables, to calculate fill. The general fill limit is 40% for more than two conductors, but the correct calculation depends on the cable types and the applicable code method. Use the actual outside diameter of each cable, not just a guess based on the tube’s nominal size.
| Route condition | Planning action |
|---|---|
| One short run with few bends | Calculate fill for the actual cables and confirm the pull path |
| Several cables in one run | Recalculate the combined fill; consider a larger tube or separate paths |
| Long run or multiple bends | Plan accessible pull points and check pulling limits |
| Future cable additions likely | Leave capacity based on a revised fill calculation, not an arbitrary spare allowance |
Follow NEC 362.30 for support: secure ENT within 3 feet of boxes or terminations and at intervals no greater than 3 feet. Product instructions or local rules may be stricter. Use fittings listed for the ENT and application. Protect the tube and cable at sharp edges, and do not crush or kink the tube while fastening it.
Keep bends broad enough for the cable. For common balanced twisted-pair cable, a planning minimum is a bend radius of at least four times the cable’s outside diameter, unless the cable maker specifies a larger radius. Follow the manufacturer’s pulling-tension limit too. Tight turns, sharp edges, or excessive pulling force can damage cable even when the tube looks intact.
Pull, label, and finish the cables
Pulling is the process of drawing cable through the installed raceway. A sound pull preserves the cable’s shape, respects the maker’s limits, and leaves the route usable for later work. Labels and photos make the finished installation easier to identify and service.
Before pulling, check that the tube is secure, the fittings are seated, the ends are accessible, and the route is clear. Use a pull line or suitable cable-pulling method, and avoid pulling hard against a sharp turn. Do not force more cable into the tube when resistance rises; inspect the route and check fill, bends, and obstructions.
As cable enters the tube, watch for kinks, crushing, abrasion, or a bend tighter than the manufacturer allows. Leave enough service slack at each end for termination and maintenance, without creating a tight coil or violating bend limits. Label both ends with the cable’s destination, such as “front camera to network switch.”
If the route passes through a fire-rated assembly, restore the opening with a listed firestop system suitable for that assembly and penetration. Do not fill a gap with an unapproved material and assume the rating is restored. Close wall openings without crushing the ENT or cable, and keep any required access points reachable.
Installation examples and route choices
These examples show common CCTV and LAN routing decisions, not a guarantee that a particular route is allowed in every building. In my work, the best route is usually the one that balances access, bend control, protection, and code requirements. The actual method depends on the structure, cable, and local rules.
A camera above a finished room may need a cable path through a wall to an accessible attic or network location. Before selecting that route, I check whether the attic is an environmental-air space, where standard cable or ENT may not be permitted. If it is, I ask the AHJ about the allowed wiring method before proceeding.
For a group of cameras sharing a route, I count every cable and calculate tube fill before installing the ENT. A tube that seems roomy at the first camera can become difficult to pull through once several cables and bends are involved. If the calculation or path is unfavorable, I consider a larger listed tube, fewer cables per route, or an added accessible pull point.
| Installation need | Practical choice | Check before closing the wall |
|---|---|---|
| One camera to a nearby network point | A direct ENT route, if permitted | Fill, bend path, separation, and access |
| Several camera or LAN cables | A route sized for the full cable count | Calculated fill and pulling access |
| Exterior camera connection | A transition suited to the location and product listings | Outdoor exposure, cable rating, and entry protection |
| Route through a rated wall | A compliant ENT path with a suitable firestop system | Assembly requirements and approved firestop details |
For an exterior camera, check the cable and raceway listings for the exposed location and transition. Indoor ENT or cable is not automatically suitable for outdoor use. The point where the route exits the building also needs protection suited to the location and the equipment.
Inspect the route before closing
A final inspection checks whether the concealed path meets the plan and remains usable. Confirm the tube listing, fittings, supports, fill, cable condition, separation, firestopping, and access. Record the route before covering it so future work does not depend on guesswork.
Before closing the wall or ceiling, verify these points:
- ENT and fittings are listed and installed within their permitted uses.
- Tube support is within 3 feet of terminations and no more than 3 feet apart, unless stricter requirements apply.
- Fill was calculated from actual cable sizes using the applicable code method.
- Required separation from power wiring is maintained, and cables are not improperly sharing a raceway or enclosure.
- Cable bends, pulls, and service slack meet manufacturer limits.
- Penetrations are protected, firestopping is suitable where required, and pull points remain accessible.
- Both ends are labeled, and you have photos or notes showing the route.
If any part is uncertain, pause before concealment. Ask the local AHJ or a qualified installer to review the route, especially where environmental-air spaces, fire-rated assemblies, or close power wiring are involved. Confirm the applicable code edition rather than relying on a general guide alone.
Frequently asked questions
These short answers cover common decisions about ENT, camera wiring, and network cable routes. Requirements depend on the adopted code, product listings, and installation conditions, so verify the details for your project before work begins.
Can CCTV and LAN cables share one Smurf Tube?
They can share a raceway only if the tube’s listing, fill calculation, cable requirements, and applicable code permit it. Count all cables when calculating fill.
Can I run Ethernet and electrical power in the same tube?
Do not do so unless the applicable NEC rules expressly permit that arrangement. Communications and power wiring generally require separation.
How full can ENT be?
Use NEC Chapter 9, Table 1, and the applicable tables to calculate fill. The general limit is 40% for more than two conductors, but the correct method depends on the cables and raceway.
How far apart should ENT supports be?
Under NEC 362.30, support ENT within 3 feet of boxes or terminations and at intervals no greater than 3 feet. Follow stricter local or manufacturer requirements if they apply.
How much separation is needed from power wiring?
Where NEC 800.133(A)(2) applies, the general requirement is 2 inches, unless an exception or permitted arrangement applies. Confirm the situation with the AHJ.
What bend radius should I use for Ethernet cable?
For common balanced twisted-pair cable, use at least four times its outside diameter as a planning minimum, unless the manufacturer specifies more.
Can I use ENT in an attic or ceiling cavity?
Not automatically. If the space is used for environmental air, NEC 300.22 and the cable and raceway listings may restrict the wiring method. Confirm before installation.
Do I need a pull point?
You need accessible ends, and a long or bend-heavy run may need an accessible pull point. Do not conceal a splice or pull point where it cannot be reached.
Can I cover ENT before testing the route?
First verify the installation, cable condition, labels, access, and any required firestopping. Photograph and document the path before closing the wall.
Does ENT make an outdoor camera cable suitable for outside use?
No. Check the cable and raceway listings for outdoor exposure and the specific transition. ENT alone does not change a cable’s rating.
The reliable way to hide camera and network wiring is to plan a code-compliant, accessible route before finishing the surface. Calculate fill, preserve separation and bend limits, install listed ENT and fittings, and document the work. When the route involves uncertain code conditions, get the AHJ’s guidance before closing the wall.
(This article was written by one of our staff writers, Michael Holloway. Visit our Meet the Team page.)
