Feeds to the Attic
Plumbing chases and chimney chases are the first places to
look when trying to find a route for feeds to the attic. When
these don’t work, you should check to see if any closets
line up from one floor to the next. You may be able to run a
piece of pipe in the corner of the closet to pull your feeds
through.
If there is an obvious way to get wires to the attic (such
as a chimney chase or plumbing chase), I usually pull a few up
there, then work down into the walls. It’s also easier to
find walls from the attic because they were often framed before
the ceiling was covered. All you have to do is lift the
insulation and look (Figure 7).
| Figure
7. Finding partition walls from the attic is
usually easy — just lift the insulation and look
for the top plates. |
Notching
It’s often
necessary to make notches in the wall and ceiling to get around
framing members. These should be as small and neat as
possible.
The most common place I have to notch is where the wall
meets the ceiling (Figure 8).
| Figure
8. After drilling one hole to find the bottom
edge of the top plate, you can drill at an angle that
will pop the bit through the center of the wall in the
attic. |
Say I’m running a wire from a wall switch to a ceiling
light. The goal is to get a wire from the wall bay up into the
joist bay. Using a 1/2-inch spade bit, I start at the corner
and drill to find the bottom edge of the top plate. I then
drill up from the corner through the plate into the joist
bay.
You may also have to make notches to get from one stud (or
joist) bay into the next. After finding the stud, I drill a
1-inch-deep hole in its center. I then drill at a tight angle
in both directions to get access into both bays (Figure 9).
| Figure
9. To run a wire across a stud or joist, the
author drills three holes: one straight in, and one
each at a tight angle into each bay. |
This leaves only a small hole to patch.
Cutting in Boxes
After
establishing where I want a box to be (Remember: Measure to the
height of the other boxes in the room, not the cover plates!),
I trace the outline of the box onto the wall. Then, depending
on the wall finish, I often scribe the outline of the box with
a razor knife. With wood paneling, scribing prevents
splintering; if the wall is wallpapered, it prevents tearing.
On a skim-coat plaster wall, scribing with a razor knife
prevents the plaster edge from splitting and peeling away from
the blueboard. Next, using a 3/8-inch spade bit, I drill out
the corners of the box, then cut it out with a cordless
jigsaw.
I carry two hole saws for cutting in round boxes: a dull one
for cutting through plaster and a sharp one for cutting through
wood and wood lath.
Plaster and Lath
Cutting
rectangular boxes into true plaster and lath requires a little
more work. After determining the approximate location of the
box, I drill 1/8-inch holes about 1/4 inch apart until I find
the space between two pieces of lath. I work my way up until I
find the next space, then I center the box on the piece of lath
before tracing the outline of the box.
I drill out the corners, then I use the razor knife to
scribe and completely remove the plaster. I like the cordless
jigsaw for cutting lath because it vibrates the wall less than
a keyhole saw. A recip saw or corded jigsaw will shake the wall
to pieces. When using the cordless jigsaw, I never let the shoe
touch the plaster. Any vibration will turn the plaster to
dust.
To finish the cut, slide a screwdriver behind the middle
piece of lath and hold the lath firmly between your thumb and
the screwdriver. Then cut the lath on one side, leaving 1/4
inch uncut. This helps keep the lath from vibrating while you
cut the other side.
After removing the middle piece, you can grab hold of the
top and bottom pieces while cutting them out.
Metal Lath
My first
impulse when I find out that a job has metal lath walls is to
run away. After my heart stops pounding, I pull out my jigsaw
with as many metal blades as I can find — I often go
through two blades for each box I cut in. The lath will also
destroy a drill bit after a couple of boxes.
Another thing to make working with a metal lath wall more
difficult is that you can’t use a tone generator. If the
energized snake touches the metal lath, the lath will become
energized, making an accurate reading impossible.
Patching
Patching your
holes may be the most important part of the job. A good
patching job creates the illusion that you were never there. I
like to patch holes as I go so I have time for another coat
before going home. Go light on the spackle to avoid
sanding.
For small holes, I use Onetime, a lightweight spackle from
Red Devil that dries so quickly I can get a second or third
coat on in the same day. For larger holes, I’ll use a
quick-drying mix-up powder like Durabond. This dries even
harder and faster than spackle, giving me a solid base coat in
a short time. The stuff dries in about 15 minutes, so mix up
only what you can use quickly. n