The Urban Legend of Painted Fire Wire

Miles and miles of exposed wiring are subject to being painted over in large commercial and industrial sites every day. These cables consist of bundled telephone, CCXTV, CATV, HVAC, data, security, access control, audio and fire alarm system wiring. This wiring is permitted to be exposed since low voltage wiring does not add to the fuel load, or produce large amounts of toxic gases when being burned by the rest of the building. This article focuses on fire alarm wiring, sometimes referred to as non-plenum alarm cable National Electrical Code (NEC) Type FPL. The following statements are the top rejected reasons for not allowing the painting of exposed fire alarm wires and cables.

1. “You cannot identify it as fire alarm wiring because it isn’t red anymore.” First of all, the FPL cable listing does not limit jacketing to any one color. It is usually red in color simply because it was initially marketed that way. Secondly, FPL is available in many colors, allowing you to more easily locate the fire alarm circuit in the junction box. Fire alarm wiring can even be blue and be printed with the letters “CAT 5e CM” emblazoned on it.

2. “You cannot read the wire type.” Yes, you can, if you look in the junction boxes and at terminal locations. There is no requirement to annually test/verify the wire type. This false reasoning could also be given for not being allowed to install wire in conduit!

3. “The wire cannot give off heat properly anymore.” What heat? Remember, this is the same cable type that is allowed to be pulled into conduit—even conduit containing several more cables. FPL cabling can even be purchased with an overall plastic jacket around a foil shield. A coat of paint has to be the least restrictive heat barrier.

4. “It changes the smoke producing properties of the wire.” No, it doesn’t. The wire is merely under a layer of paint; and while the paint may smoke, it will smoke no more than the rest of the paint on the walls in the room on fire. If paint can cause deadly smoke, then you shouldn’t be allowed to paint the room in the first place. Also, rooms with painted wiring are usually those with open contents below—like a big-box store. These occupancies contain any and everything—most of which is nasty stuff when on fire. That exposed wiring on the ceiling is inconsequential considering the overall volume and range of the fuel load below. This is the “small stuff” we aren’t supposed to sweat over.

5. “It changes the flame travel properties of the wire.” No, it doesn’t. The wire still has the same flame properties through the fire barrier penetrations, presuming the wire was not pulled from the wall, painted and reinserted through the fire barrier. Keep in mind that the paint cannot be the bad guy here; after all, the room is covered with it.

6. “The wet paint can chemically alter the insulation, break it down, or cause it to soften.” In researching this issue, I was unable to talk to paint industry insiders, or find any studies indicating that different plastic jackets and coverings have been tested as being compatible with each other. I could find no instances where anyone laid various insulators, from different manufacturers, together in the same conduit to check for an interaction between the different polymers used in the various wire and cable manufacturing processes.

7. “It is not allowed.” Unless required by a local ordinance, I can find no code stating that while it is OK to paint the ceiling and it is OK to run the wire exposed on the ceiling, it is not OK to get them so close to each other that the paint actually covers the wiring. After all, the job of paint is to cover stuff. One could also argue that paint is good, as it helps protect the wire from external heat and airborne solvents, as well as the effects of acid rain, pollution, humidity, moisture and ultraviolet light.

This is an issue for the paint industry to clear up, rather than the low-voltage industry. One paint association technical representative responding to my inquiry on this topic stated that water-based paint and primer should “not pose any problems.” On the other hand, he did not flatly state that other paints based in oil, epoxy or other nasty stuff, does also not pose any problems. While this issue gets fine-tuned, be sure to charge a fair and reasonable fee to change any wiring the owner is being told “needs” to be replaced because they painted it. As it stands now, the blanket statement: “painting exposed wire ruins it,” is an urban legend that needs to be addressed by the paint industry, in an official manner. I will go out on a limb and publically state...No one should complain about water-based paint on jacketed cables since the actual wiring insulators would be protected by the overall jacket from any un-likely effects of the water-based paint. Until this paint thing gets decided don’t even think about staining!



Greg Kessinger is SD&I’s longtime resident fire alarm and codes expert. His column is the longest, continually running contribution in the 34-year-history of the magazine. He can be reached at