Wire Fishing Guide
The ultimate guide to fishing wires through walls, ceilings and cabinets. With the help of these tips and tricks you can become a wire fishing expert.
Fishing wires and cables through finished walls can be a perplexing and intimidating assignment. It’s tempting to cut in access holes all over the place, but you don’t have to do that if you play it smart. With a few simple tools and these tips you’ll avoid a whole bunch of drywall patching and have more time for real fishing!
Check the whole wall cavity with a stud finder
A decent stud finder is a must-have for every wire-fishing job, but don’t throw it back in your pouch after you’ve located the studs. Use your stud finder to check the whole wall cavity for obstacles like blocking and abandoned headers. You don’t want to find out the hard way that you should have fished your wire one stud cavity to the left or right.
The tools you need
Flex bits and glow rods are the go-to tools for fishing wires. Flex bits are great for drilling holes in hard-to-reach spaces. The two most common lengths are 5 ft. and 6 ft., but extensions are also available. A 3/4-in. x 54-in. flex bit costs about $50 at home centers. Buy a bit that has a hole on the end of it so you can use the bit itself to pull wires.
Once your hole is drilled, you can shove a glow rod through the hole, attach your wire to the eyelet at the end and pull it back through. Glow rods can also be used to hook wires to pull them out. As their name suggests, glow rods glow in the dark. This makes them easier to spot when you’re working in dark areas (which is most of the time).
Glow rods come in various lengths and thicknesses, and you can combine as many sections as the job requires. Thinner rods flex more and work better when you have to make sharp turns. A thicker rod can span longer distances and is better for hooking wires that are more than a few feet away. A 9-ft. glow rod kit costs about $38 at home centers. Expect to pay about $60 for a 24-ft. kit.
Push through more than you need
When hooking a wire to pull it toward you, make sure that there’s more than enough wire to hook on to. Sometimes it’s a real challenge to grab hold of a wire, and once you have it hooked, you don’t want to lose it. It’s smart to make sure that you have at least five or six feet of extra wire to keep up the tension on the hook the whole time you’re hooking it.
Hook on to a flex bit
Sometimes you don’t need to use glow rods at all. Most flex bits have holes in the ends of them. If you have access to where the flex bit pops out, attach your wire directly to the bit and fish the wire through that way. It works to twist the wire and tape it up, so that it doesn’t come off when you’re pulling it back through.
Fish wires through the holes for recessed lights
When you’re installing new recessed can lighting, fishing wires from one light to another is easy because you have a great big hole to pull the wires through. But even if you’re not installing new lighting, you can use the existing openings. Many cans can be easily popped out of the opening by removing a few screws.
Protect drywall with a mud ring
Mud rings, also called drywall brackets or low-voltage “old-work” brackets, are great for protecting the drywall when you’re drilling with a flex bit or cranking on a glow rod. They’re easy to install (just tighten two screws) and cost less than $2 at home centers. Once the wires are connected, you can screw the wall plate to the mud ring.
Mud rings are approved only for low-voltage wires like communication and coaxial cables. If you need to install a regular gang box for an electrical receptacle or wall switch, install the mud ring temporarily to protect the drywall while you fish the wire, then remove it.
Install conduit inside cabinets
Additional outlets above the counter space—that’s one of the most popular electrical retrofits. And really all you have to do is fish yout wire through a flexible conduit installed right through the base cabinets. If you drill the holes for the conduit as far back and as high as you can, no one will ever notice.
Invest in a Bumper Ball
Wires aren’t supposed to be installed any closer than 1-1/4 in. from a penetrable surface (the outside of the drywall). That means you shouldn’t be drilling holes right next to the drywall. But it’s not always easy to control where a flex bit goes. A Bumper Ball flexible drill bit guide installed on the end of your flex bit will help maintain the proper space between the bit and the outside of the wall cavity.
Get a better view with an inspection mirror
You know your wire is in there somewhere, but you just can’t seem to find it. It’s probably hung up on another wire or pipe, but guessing isn’t going to solve the problem. Shine a flashlight onto an inspection mirror to find out exactly what’s going on. This is a simple, inexpensive tip that can save you a lot of time and frustration. Pick up an inspection mirror at an auto parts store for less than $10. Or bump it up a notch and pay a few more bucks for a mirror with small built-in lights.
Don’t spin the bit in insulation
The best advice for fishing wires through insulation is “avoid it if you can.” The potential is always there to damage the vapor barrier or bunch up insulation, leaving cold spots in the wall. If you must fish wires through exterior walls, the best tip is to avoid spinning the flex bit until you make solid contact with the wood you plan to drill through. If you drill too early, you’ll end up creating a large insulation cotton candy cone, which will make retrieving your bit difficult, if not impossible.
We’d Love to Hear From You
Do you have a jobsite or tool tip that makes your work-life easier, safer, or just more fun? Why not share it with your construction comrades? Plus, you can show off your professional prowess to your family and friends.
Click the image below to send us your Pro Tips! Please include an image if you can. We will contact you if we run your submission on the site.