"blueman" wrote in message
...
blueman writes:
I need to run a wire from a switch on the wall up the wall and across
the ceiling to a new overhead light. (Note that unfortunately, the
joists run perpendicular to the direction that I need to traverse the
ceiling)

Doing so presents the following two problems for me:
1. How do I make the right angle turn through the top plate and into
the ceiling joist bay?

2. How do I go through the joists as I traverse the ceiling from the
wall edge to the center light location?

Note I don't have the option of using an unfinished attic or basement
to help me. I am trying to avoid ripping up more plaster than I need to.

I plan on buying a long flexible 1/2" bit which I believe should at
least help me with #2, though I'm a bit short on the details of where
I drill the entry and exit holes and how I achieve the right bend and
angle to go through the middle of the joist.

However, I am a lot more stumped about how I make the right angle
transition from the wall bay into the ceiling joist bay.

Could anybody give me some detailed pointers and/or point me to any
online videos? (I tried googling but found only general suggestions
such as using a flex bit)

Thanks.

Here is my report back on what I did and how I did it.

I ended up going the direct route of snaking across the ceiling and
down the wall. Again, my primary priority was doing this in a lasting
and professional way since I feel an obligation to the generations of
previous owners of our historic house (main part is Italianate built
in the 1860's and the garage is part of a wing that reportedly dates
back to the late 1700's!!!).

First, cutting through the ceiling was even harder than anticipated --
even to just cut out the hole for the ceiling box and the intermediate
holes for snaking the wires. There were multiple layers. Starting from
the exterior:

1. Rough 1/2" layer of hard plaster/stucco
2. Tough metal lathe. Actually the lathe on the ceiling was mostly solid
metal with some grooves. The lathe on the sides was thick fine
mesh.
3. Another 1/2 layer of plaster keyed into wooden lathe
4. 1/2" wooden lathe
5. Loose fill insulation (not sure what it is but it was very light,
gray in color and almost like very light sawdust or cotton whisps)

I needed to use a diamond cutter in my rotary zip saw to cut through
the stuff and it made a real mess -- unfortunately, I didn't have a
helper to hold a shop vac...

Also the joists were irregularly spaced and more like 4x lumber.
There was also a fireblock-like horizontal element in the stud
bay. Luckily by removing the wooden lathe (which itself often had a
gap between it and the underlying structural member), I was able to
find plenty of room to snake my pull string without having to drill
through (or notch) the structural elements. I added metal plates over
any place that I passed over a structural element.

I didn't end up needing to notch the corner since there was plenty of
room to bury the cable below the structural lumber due to all the
layers. I again added protective metal plates.

To prevent the loose fill insulation from continuing to leak out from
the ceiling holes on me and the floor, I stuffed in some loose
fiberglass insulation (pulled off some extra bats). This served both
to replace some of the stuff that fell out and also served as a block
against new loose fill floating out which otherwise continued to fall
on me and the floor.

Even after creating the path, pulling the wire through was still very
difficult despite the fact that the path was only 10 feet long and had
only one corner (at the floor-ceiling junction). This was presumably
due to the irregular nature of the space and protruding nails,
plaster, etc. along the pull path.

I filled in the holes in two steps. First a layer of 20minute setting
compound directly over the lathe or metal plates (I find the setting
compound to be very hard and durable). Then a skim coat of a
concoction that I made to mimic the existing surface created out of
combining about 1-part ready mix stucco patch compound with 1-part
setting joint compound plus water and some Zinser primer (to match the
color since the walls/ceilings seem to be more whitewashed than
painted).

Rewiring the switch box was also a PITA since it was part of a 4-gang
bakelite plastic box embedded in the tiled kitchen backsplash (which
is on the other side of the garage wall). To feed in the new wire, I
ended up needing to literally bust out the old embedded bakelite box
and replaced it with a 4-gang 3-1/2" deep metal box -- I wanted the
extra room since 2 of the 4 switches were three way (including the
gargage light one) and 2 of the switches were big elements (1 Lutron
dimmer and 1 Aube timer) -- there were a total of 8 wires passing in
and out of the box (all same circuit though).

While doing it my way took a LOT longer than some of the other
suggestions, I accomplished the following:
1. No unsightly external boxes or track mold
2. Minimum patching (just a couple of small holes)
3. Minimal mess from demolition and from leaking loose fill insulation
(had I ripped out a large swathe, I would be drowning in fallen
insulation and plaster --- and I would have needed to find a way to
replace insulation in the entire joist bay)
4. Minimized amount of cutting through solid metal lathe
5. No disturbing of structural elements.
6. No intrusion or damage to other adjoining finished rooms.



*Sounds like a nice job was done. Thank you for posting back with details.