If they're your only source of built-in light in a room, allow one fixture for every 25 square feet of floor space. For good ambient lighting, use floodlight reflector bulbs. Spotlight reflector bulbs are a good choice for precise accent lighting.
Installing recessed fixtures isn't difficult. If you have dropped ceilings or access from above from the attic, for example that's easiest of all. The job is a bit trickier when you don't have access, but fortunately, most manufacturers offer special "remodeling" fixtures, also called "cut-in cans." They're rated for safe contact with insulation (indicated by the letters "IC"), and they're the best kind to install from below, whether there's insulation or not.
The other major consideration is proximity to power. If there's already a ceiling box where you want your light, simply disconnect the wires from the box and reattach them to the cut-in can. (Cut-in cans come prewired to their own junction boxes.) As you'll see below, you simply cut a circular hole in the ceiling, attach the lead wires to the junction box and slide the fixture up into the ceiling until the fixture's mounting clips catch. With a power source in the ceiling and a switch in the wall, you're ready to proceed.
If there's no electrical outlet handy, you may want to hire an electrician to run wire to the new fixture. But first have a look at How to Fish Electrical Cables. With a little spunk, you can save a bundle and have the satisfaction of doing it yourself.
Buy an insulation-contact (IC) rated fixture. When insulation touches an improperly rated recessed light, fire can result.
If you run cable into a new junction box and from there to the new light, the junction box must be in an accessible place (usually the attic or basement) and not covered with drywall or the like.
Step by Step
1. Cut an opening and wire the light. Turn off the power. Use the electronic stud finder to locate ceiling joists. Trace the outline of the fixture onto the ceiling. Then, with a tarp beneath, use a drywall saw to cut the opening (or enlarge an existing opening) for the recessed light between the joists. A jigsaw with a plaster-cutting blade will make the job easier, but be careful not to cut through existing cables hidden in the ceiling. Another handy tool, especially if you're putting in several recessed lights, is a drywall circle cutter. It's precise and easy to use.
Insert the electrical cable into the fixture's junction box and fasten it with a cable clamp. Strip the wires as needed, then splice them to the fixture wires with twist-on wire connectors. Connect the fixture's black wire to the black house wire, then white to white and ground to ground (green or bare wire). Stuff the wires into the box and fasten its cover.
3. Install inner baffle and trim. Once the housing clips are snug, attach the inner baffle and any other trim to the fixture housing, according to manufacturer's instructions. The baffle shown is typical of recessed fixtures: it attaches with springs. Install the bulb, restore power and enjoy your new light.
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