How to Fish or Snake Wires in Walls
and Ceilings
Trying to snake or fish a wire in a wall or ceiling can be very frustrating if you
have never done it before. Even if you have not knowing a few tricks could
double the time it takes. One of the key elements in snaking wires is the ability
to visualize what you can't see. Anyone who needs to snake wires on a regular
basis would be well advised to visit a new construction site. There are certain
aspects of construction that can help you even though you cannot physically
see them

For example, and I will show you diagrams further on, you can make some
assumptions. If the roof line goes in one direction, in most cases the ceiling
rafters run in the other direction. Bearing walls are more apt to have cats(wood
braces) inside them that will prevent snaking a wire. Outside wall will have
insulation in them. These are just some of the things that can help you see what
you can't see.

There are some basic tools and materials you will need for fishing wires. The
first and most important is a fish tape. For most occasions, you'll want a 1/8" x
at least 50 feet and preferably 100 feet. Here is a list of some other items you'll
  • Electrical Tape
  • A Flashlight
  • Cordless drill
  • Wood spade bits
  • Wire Staples
  • Hammer
  • Sheetrock Keyhole Saw
  • Lineman's Pliers
  • Wire Strippers
  • Steel Fish Tape

You may not need every single thing listed and above and you may need more.
It really depends on where you will be snaking the wire and what type of
materials are involved.
Okay so now we are ready to snake our wires. For the first example lets say
we are going to add a center light in a room where there is no light but there is
a switch that controls a receptacle. This section is on snaking wires, so I am
not going to get into the actual electrical wiring or splicing. In the first example
lets have an accessible attic above the room we are adding the light in.

First thing we need to do is open the switch up and pull the switch out. You
should turn off the electricity for this circuit so you don't have any accidents. The
snake is metal and can easily become energized by touching a wire or the
switch. Once you have the switch pulled out you'll want to see if you need to
push a knockout out in the back of the box on top. The idea here is you are
going to go in the attic and drill into the plate above the switch so you can
snake a wire down.

Before you go to the attic you need to find a way you can find the top of the
plate. If there are any AC vents in the ceiling, that is the easiest way to get
some measurements. If not then look for something that goes through the
ceiling that you can use as a reference point. If you can't find any way to find the
plate and where you need to drill a last resort is to stick a long thin screwdriver
through the ceiling directly above the switch. Once you have your location in the
attic and you found the top of the plate, you will need to drill a hole. I
recommend a decent size hole. A 3/4" or 1" spade bit will accomplish this.

When you drill you will want to be in the center of the plate and drill straight
down. At this point if you are doing this with a partner, your ready to snake the
wire. If you are by yourself here is a
little trick  Drill another hole next to the one
you just drilled. It can be smaller, like 1/2". This will be a hole to shine your
flashlight down. If you are doing this with a partner you can have them shine a
light into the switch box. Then from the attic you will be able to look down and
see the hole you knocked out. Now it is a matter of sending the snake down
and guiding it through that hole. It may take a little doing but you'll get it. Once
you do your helper can tie the wire onto the snake and you can pull it up. Once
you have the wire in the attic, it should be an easy matter to run it over to the
new lights location.

If you are doing this by yourself you can shine your flashlight down the second
hole and guide the snake through the hole in the switch box. You will have to
then go down and attach the wire. It is important that you make a smooth nose
on the snake since you will not want it to get hung up when pulling it from the
attic. This part can go much smoother if you can get a helper for a few minutes.

The illustration and photo  above should help you visualize what you will be

Another possible scenario is that there is no attic above the location you are
working in. In this case you will need to notch some sheetrock. You will need to
know which way the studs or ceiling rafters are running to do this. If you need to
go from point A and point B and the beams are running in that direction you'll
be able to snake a wire in that direction. Where the beams are running in the
opposite direction, you will need to cross the beams somehow. The best way
would be to cut a strip of sheetrock out that is about 4" wide and the length you
need to get to. Then you can drill a hole in each stud and run the wire through
the studs or ceiling joists. The illustration below shows what this would look like.

There may be times when cutting and patching a big section of ceiling is not
practical such as an old plaster ceiling. Another option is to make small
notches and pass the wire through each hole to pass around the stud. If you do
this you should also notch the beam so the wire is recessed or get metal plates
to protect the wire. If the beam is notched it mustn't be cut too deep as to affect
the structures strength. The illustration below shows what this notching would
look like.

Continue for  More Tips and Tricks for Snaking wires in walls and ceilings
(C)Copyright 2006 Forte Electric Inc.
Forte Electric Inc.
How to Snake a Wire
Illustration Fish Wire in Wall
Photo Snake Wire in Wall