Have you ever walked into a room in your home, noticed dark, shadowy spots, and wished there was an easy way to add lighting in the drywall ceiling? Or have you ever wanted to add a speaker in a ceiling and connect it to your audio sound system? As an electrical contractor, you may be asked to do one of these tasks or something similar in an existing home for a customer, or for that matter, in your own home.

But before you get started, you’ll have to consider how to integrate the new devices with the look of the old. Can you find new luminaires to match the existing recessed cans and trims or existing surface-mounted luminaires that will match, or will you have to replace all of the existing lighting with new? The latter may be cost-prohibitive. Will you change the recessed can light trims to match the new can lights that are being installed, or will you use LED kits to provide 1,200–lumen downlighting for both the new and existing cans? (If you choose LED kits, ensure they are listed for use with the particular existing can light.)

Once you have determined how to match the new luminaires and trims to the existing or, when the existing luminaires cannot be matched, have ensured you can purchase new trims and complete luminaires that match each other, the next step is to evaluate the existing installation. You must develop a plan for how to install the new lighting in the existing installation. For example, is an attic accessible in the area of the new lighting and existing lighting, or must you stay within the same joist space as the existing lighting where an attic is not available? These are questions you must ask and answer before you can provide the customer with an estimate.

Once you have determined a price, the customer has accepted, and all parties have signed the contract, purchase any special tools needed to help you effectively accomplish the project with the least amount of labor and as little mess as possible.

For existing installations with ceiling trusses in a home with an attic, on the first floor of a multiple-floor home with joists or a flat-roofed home with joists, you’ll need a stud finder to determine where the structural wood framing is located behind the drywall. Stud finders can be magnetic or electronic. The magnetic stud finder uses powerful magnets to locate metal nails, metal screws or metal plates that are part of the joist or truss in the ceiling or wooden studs in the wall. These magnetic stud finders are only going to sense metal behind the drywall, and thus, it is very old technology and may not be the best use of your time and money.

Modern stud finders, while somewhat more expensive, actually sense the change in density of the drywall and wood combination.

When I reviewed the technical information on electronic stud finders, an expert on these devices explained that these devices detect the dielectric constant of the wall and ceiling. When the sensor is over the stud, a lower reading on the display indicates a stud, joist or truss. Some of these devices may also detect energized nonmetallic-sheathed cables and metal water lines under the drywall.

My advice is to try both magnetic and electronic and use the one that works best for you.

Once you have located the support structure in the existing ceiling and determined the luminaire’s appropriate location relative to the existing luminaire’s location, all that’s left is to cut a hole in the drywall with the size based on the type of luminaire to be installed. You can use old-fashioned hole-saws or adjustable drywall and ceiling tile hole-cutters. One such tool actually has the cutter and blades inside a clear plastic tub that catches debris from the cutting.

Modern technology makes adding lighting to a home a much easier chore than in the past, but verify the location of plumbing, air conditioning ducts and equipment, as well as other electrical circuits before attempting to install new lighting in existing homes. A small hole drilled in the drywall can provide access for an inexpensive microcamera that can help determine any hidden issues.