Best way to wire for recessed lighting

Question

We are considering installing recessed lighting on a ceiling that has another floor above it. The ceiling currently has no light fixtures except a central ceiling fan.

I can't access the ceiling from the floor above. I'd like to avoid having to rip down the entire ceiling to get at the joists and run wires perpendicular to them.

No, I don't have any other "special access" like around the edges of the ceiling. I will have to do everything from underneath it, while inside the room.

What are some good tools and methods for running wires from one recessed lighting fixture to the next? Fishing from one fixture to another in the same joist bay seems pretty straightforward, but how do I get wiring through the joists across multiple bays? The ceilings are higher than a normal room, so it's likely that I will have to run through 3 or 4 bays between lighting fixtures.

I'd also appreciate any advice on things to watch out for. I already know that there is no ducting or piping in the ceiling, but there may be wiring. How do I ensure that I don't run into existing wiring?

Answer 1

I'm sure many of the experts will have their own tricks. Here are a few from a non expert. Use thumbtacks to position your light locations. Get a straightened out hanger and bend a piece equal to the radius of the hole you'll be cutting 90 degrees. Shove the radius piece through the ceiling at the center of your proposed light cutout. Work it in so the radius piece is now laying on top of the ceiling. Spin the hanger around while pushing it further up into the ceiling space. If you hit something, you'll know the light won't fit there and you can adjust the location.

Once you've checked out all your locations, you can start cutting the holes. Running the wires along the joists will be the easiest part. You can use a fish tape but I usually just use a tape measure because it lays flat and easy to navigate. The wires across the joists are more of a problem. You'll have to cut the ceiling at each joist location and notch the joist. Fish the wire through and around the joist and into the notch. Cover the notch with a nail plate. If a joist is close enough to the hole, you might be able to get up there with a drill and drill your hole through the joist. When all done, repair the ceiling with some mud and tape.

I've seen many ceilings that had the drywall attached to furring strips installed perpendicular to the jousts due to joists not being "perfectly" installed. Then your wires would just go between the drywall and joist..... you won't know until you look in a hole.