If you've ever installed a home theater or added an electrical outlet to an existing room, you may have questioned the best way to run the new wires through the wall. While every situation is a little different, most of the time, you can install the wires with minimal damage to the wall or walls.
Snaking and Fishing
As the names imply, snaking and fishing involve hand-feeding stiff wires, cables or rods through existing walls, floors and ceilings to connect new wires to outlets or mounting brackets. Stud spaces are notoriously dark, so it can be a guessing game at times.
You can usually run the new wire up and through the ceiling plate -- or down, through the floor plate. Before starting, round up the tools you’ll need.
- Cable fish tape (or rod kit)
- Drywall saw
- Stud finder
- Electrical tape
If you are running electrical wires, always turn off the electricity at the breaker panel.
Check the selected stud space with a stud finder or by rapping on the wall with your knuckles. If you locate a fire block -- a board that spans horizontally from stud to stud -- call your local building authority before drilling through it. If they allow you to drill through the fire block, you will probably have to seal the hole with fire-rated sealant after running the wires.
Cut the drywall to the size of the new outlet box or mounting bracket. If you have attic access, from above, drill a 3/4-inch hole in the ceiling plate(s). Alternately, you can run the wire downward, by drilling through the floor plate if you have a crawl space or basement.
Snake the Wire
Run a snake rod, stiff wire or cable fish tape through the newly cut hole in the drywall and through the hole in the drilled plate. With any luck, the tip will slip through without too much wiggling and poking.
When you get it through, attach the new wires to the cable tip; wrap with electrical tape, and pull the cable, wires and all, back through the hole in the drywall.
- You can buy or rent an extended, flexible drill bit that allows you to drill the top plate from inside the stud space.
- Some snake rod kits feature luminescent rods that actually glow, making them easier for you or an assistant to spot in a dark stud space.
- If you encounter a blockage, shine a flashlight on a small mirror just inside the wall to get a better look at the problem.
If you have to drill through a fire block, you’ll have to cut out a section of drywall just above or below the block to reach it. Cut a nice square shape and you’ll be able to use a California patch to cover it up.
When possible, avoid running wires through insulated stud spaces, which can cause bunched-up insulation and reduced R-value.
When You Can’t Go Up or Down
Sometimes, it’s just not feasible to fish wires through the wall the traditional way. Maybe you are a tenant, or maybe the local building authority doesn't allow you to drill through a fire block. You still have a few options.
If you can’t go up or down, you might be able to go horizontally. If you can fish the new wire to floor level, you can cut away a strip of drywall at the bottom of the wall, run the wires, and install tall baseboard to cover it.
For Ethernet, speaker and telephone wires, install a cable cover just above the baseboard, and conceal the wires within.