During construction or remodeling, installing wires inside of walls is easy when the wall studs are open and exposed. But once the drywall is in place, it becomes much more difficult to feed—or fish—wire through these hidden spaces. That's where fish tape comes in handy.
What Is Fish Tape?
Available in 25-, 50-, 100-, and 200-foot lengths, the fish tape is rolled up and stored in a round, plastic casing. The fish tape is manually pulled out of the casing and then is reeled up by rolling it back into the casing, though there are powered fish tapes that reel in the tape automatically.
What Fish Tape Is Used For
Fish tape is used for pulling:
- Electrical wire through electrical conduits
- Electrical wire through holes in studs
- Electrical wire vertically from floor to floor
- Ethernet wire from room to room for Internet access or for home theaters
- Coaxial wire or speaker wire for audio systems or for home theaters
Watch Now: How to Pull Electrical Wire or Cable Through a Conduit
Always wear safety glasses when working with fish tape. Fish tape's stiff metal wire can be dangerous if allowed to unreel all at once. The fish tape casing only needs to be opened when replacing the tape; otherwise, keep it sealed up.
Take extreme care when opening the casing. All of the tape must be removed in advance.
The new fish tape will have support ties around it that hold it into a coiled shape. Leave the ties in place until after the tape is safely in the casing. Then, remove the ties and close up the casing.
Fish tape is often metal, so it is a conductor of electricity. Turn off electric circuits in the area where you're working to avoid being injured by electricity. Non-conductive fiberglass fish tape is also available.
How to Use Fish Tape
Unreel Fish Tape
Start to unreel a few inches of the fish tape out of the plastic housing. You may need to push a button to release the tape. Other types of fish tape do not have buttons; you simply pull the tape out.
Feed Fish Tape
Push the fish tape forward to feed it into the conduit or through the holes in the studs. Feed the tape until a foot or two are exposed at the other end.
Attach Wires to Fish Tape
Rip sheathing from the electrical cable to expose several inches of wire. Strip the ends of the wires to expose the copper. Twist together the wires. Attach one of the wires to the end of the fish tape. Bend the wire to form a complete loop.
Wrap the wires with electrical tape. Start where the wires attach to the end of the fish tape and end at the start of the cable sheathing. Wrap tightly. Do not use more than one layer of tape. Be sure the open end of the double loop is on the end of the fish tape. Otherwise, it can get stuck on couplings and be pulled back.
Pull Fish Tape
Pull the fish tape slowly back. Work slowly, as a helper unspools the electric cable on the other end.
Detach Wires From Fish Tape
Reel back all of the fish tape until the electrical cable appears. Make sure that about a foot or more of the cable is exposed to prevent it from retracting back and being lost. Unwrap the tape and remove it. Untwist the wires from the fish tape and remove them.
Tips for Using Fish Tape
- For long pulls or for going around corners, reduce friction on the wire by using wire-pulling lubricant.
- Work as a pair. One person pulls the wire back, while the other person uncoils the electrical wire and pushes it through.
- For cables with four or more wires, it helps to cut the wires to staggered lengths. When wrapped with tape, the bundle will be slimmer and easier to pull.
Fish Tape Maintenance and Repair
Well-maintained fish tape can last for many years. Because fish tape is subjected to stress and poor conditions within the wall, it does need occasional maintenance and repair. Follow the below guidelines to keep your fish tape in usable shape for as long as possible.
- Never roll fish tape into the reel when it's wet. To avoid rust, run wet tape through a towel as you reel it back. Even with dry fish tape, occasionally run the tape through a towel to clean it off.
- Straighten out kinks or sharp bends in the tape by gently forcing the tape backward by hand. To coax difficult fish tape to re-form, first apply heat with a butane torch. Then, re-form the tape with two pliers.
- Similarly, if the end of the fish tape loses its distinctive double-loop, apply the torch until the metal is red-hot. Then, use two needle-nose pliers to re-form the end.