To efficiently light up a two-car garage, remove the bare-bulb porcelain fixtures (remember to turn off the power first) and replace each with an 8-ft. fluorescent fixture. (We recommend one 8-ft. fixture per vehicle space.) We like the type that use 4-ft. bulbs; the 8-ft. bulbs are difficult to handle. You can position the new lights to mount right over the existing ceiling boxes.
Keep in mind that not all fluorescent lights work in cold weather. Select your fluorescent fixture based on the lowest temperature in your garage. Refer to starting temperatures printed on the ballast. Regular magnetic ballasts in standard T12 fluorescent fixtures (which have 1-1/2 in. diameter lamps) are not recommended for temperatures below 50 degrees F.
If the temperature in your garage drops below 50 degrees, buy fixtures with electronic ballasts (not electromagnetic) because they start in temperatures down to 0 degrees F and lower. We recommend you buy fixtures that take size T8 lamps (1 in. wide), which are more energy efficient. They cost more initially but will save you money over time. Avoid energy-saver T12 lamps; they need a minimum of 60 degrees to operate properly.
When buying bulbs, especially for a woodworking shop where you need to see the true color of paints and stains, ask for lamps with a CRI (color rendering index) of 85 or above. This number usually isn't printed on the bulb or packaging, but it’s listed in the bulb company’s product catalog (and on some Web sites).
Once you know the exact ceiling fixture location, drill a 7/8-in. hole in the base of the fluorescent light's metal housing, directly over the existing ceiling box. Buy a 1/2-in. electrical bushing (at home centers and hardware stores) and snap it into the newly drilled hole so sharp metal edges won't cut into wires. Then attach the fixtures to the drywall ceiling by screwing them directly into ceiling joists.
Note: Make sure a ground wire is present and fasten it to the metal body of the fluorescent fixture.
A Well-Lit Garage
Overhead fluorescent fixtures provide ample light for doing woodworking projects, or working on your car, motorcycle or boat.