Fishing Cable Through a Wall from Above
If your school
has a dropped ceiling or
an unfinished attic, you can probably fish cable
from there to jacks in the wall immediately below. The
illustrations below show the process in reverse.
Find the wall's
top plate and bore a 3/4-inch hole through it. Thread fish
tape through the hole into the wall and have a helper
yell when the hooked end of the tape reaches the wall opening.
Your helper might need a coat hanger to grab the tape.
to the fish tape as shown, then reel in the tape and cable.
Once you've pulled the whole run, leave enough slack at
the jack end to reach the floor and extend another 2 or
the fish tape hits something about halfway down the wall,
you've encountered blocking nailed
horizontally between studs. To get cable through, you'll
need to open up the wall there and cut a notch in the blocking.
Keep in mind that studs and joists are typically spaced
with 14 1/2 or 22 1/2 inches between.
in Walls, Ceilings and Attics