New lighting technology provides electrical contractors with a unique capability to redo an aging home and vastly improve the lighting system. At the same time, many aspects of an existing home, such as its construction, can pose challenges. ECs must find a way to work around them.
Before an EC can install a new lighting system, he or she must first consider the home’s construction. Knowing the location and date the home was built, an EC can make some educated guesses. For example, many homes in the South have a crawl space underneath, while those in the North and Northeast tend to have basements.
The home’s construction will determine the difficulty of the lighting reconstruction and the scale of repairs the home will require after the installation. If there is either a crawl space or an attic space, is there enough working space for an electrician to access walls and ceilings? The less accessible attic or crawl space, the more repair work will have to be done.
Another consideration is whether the home is a single-story, two-story or multilevel home and the access points for new lighting control and luminaire wiring. A tri-level or split-level home may have an attic, but since the home actually has three levels, the concrete slab on the lower level and the second level would not permit easy access to the ceiling or walls. In a tri-level, only the top floor is easily accessible.
When working in an accessible attic, there are many tricks ECs use during a rewire of an existing structure. I don’t profess to know all of these tricks. There probably are as many tricks out there as there are electricians.
One I’m aware of is, when installing new Type NM cable in an existing wall from an accessible attic, drill a hole in the studs in the attic. Using a flashlight, determine if there is insulation inside the wall (commonly found in outside walls). If there is insulation in the wall, a tape measure with the end cut off can be used to go behind the insulation to the hole for the box. Install a hole in the tape and insert one of the conductors of the NM cable into the hole, tape it up and use the tape to pull the cable into the attic. If no obstructions are visible in the wall space between the studs, a smooth chain can be dropped through the hole in the stud. A hole can then be cut into the drywall in the room for the future box, and the NM cable can then be attached to the chain and pulled into the attic for termination in a new luminaire’s ceiling box.
Here is another. Flexible spring steel shank drill bits with wire fishing holes in the head and the shanks are available in various sizes from ½, ¾, 3/8 and 9/16 inches and up to 54 inches long. These flexible shank bits can be used wherever the length of the flexible drill bit permits in the attic and can be used with a flex bit placement tool through a hole for a box in the drywall to drill into the attic plate. Care should be taken to always know what is on the other side of the stud before drilling.
One more: When installing a new box for a ceiling- mounted luminaire, always check in 314.27(A)(2) for determining the requirements for ceiling outlets. For a ceiling-suspended paddle fan, 314.27(C) requires outlet boxes used as the sole support shall be listed, shall be marked by the manufacturer as suitable for paddle fan support, and shall not support ceiling-suspended paddle fans that weigh more than 70 pounds.
Next month, I will cover the new types of lighting technology and dimmers available on the market.