I am in the process of replacing the wiring in my in-laws 100 year old
house. So far the work has been in the basement, with short runs up to the
appliances. But now I'll need to run wires up to the attic for ceiling
lights, fans, and smoke detectors.
The current knob and tube wiring actually runs along the OUTSIDE of the
house between the basement and attic, and is seriously corroded with
crumbling insulation. Obviously, this is not an acceptable way of routing
Normally I'd just drill a hole at the top, one at the bottom, and dangle a
string down to connect the two. But as is common in these old houses, there
is blocking partway up inside the wall. They have 12 foot ceilings, so I
don't know yet whether there is a single block, or additional blocks.
I DO NOT want to cut into the old plaster and lath walls, so what is the
best way to get a wire through the wall in this case? I remember seeing
really long drill bits at Lowes, but I don't remember how long they were,
and am concerned they wouldn't reach far enough into the 12 foot high
If all else fails, I figured I could mount a length of conduit in the
corner of one of the closets, as a chase to run wires from the basement to
the attic. But I'd prefer to fish the wires in the wall if possible.
You could find wind bracing in the walls, which are criss crosses, and they
make snaking really tough. You don't say how many floors are involved, but
if it's just one, you can easily run lines inside a closet from basement to
attic. If it's two floors and you find two closets, one on top of another,
you can go through both. Also you may find a cast iron stack pipe in the
attic, which often has enough space around it to drop lines from attic to
basement. If all else fails, run a conduit outside the house
On Sat, 27 May 2006 11:48:43 -0400, "RBM" <rbm2(remove
You may also find, if the house is post-and-beam, heavy timbers that
you don't especially want to put holes in.
If you're re-wiring, wouldn't this be a good time to re-insulate as
well? If you're going to be doing both anywhere near the same
time period, you're better off just opening the walls.
In our case, the house is standard platform construction; studs, joists,
My in-laws house needs a LOT of improvements, including insulating, a
complete gutting and rebuilding of the rotten bathroom, etc. But they both
have serious health issues and are living on a fixed income. So we're
working off of very limited funds they've saved up over the years, and what
little we can afford to contribute ourselves. Their home insurance is sky
high because the electrical wiring was a fire waiting to happen and they
heat with space heaters. So I'm replacing the wiring and adding in some
permanent wall heaters.
As it is, I just had to replace 90% of the plumbing for what started as a
leaky faucet. You know "while you're here, can you take a look at our
faucet...". They had an old wall mount faucet in their kitchen that was
leaking around the stem. Turned out to be a rusted and broken spout. I
couldn't find a new spout, but I did track down a replacement faucet. Of
course, when I tried to remove the faucet, the rusted pipes broke instead.
When I tried to replace the broken pipe, another section farther down the
line broke. It continued to escalate till I was halfway through the house!
:) So I just replaced the majority of the plumbing with new pipe, and
installed a new sink with a standard deck mount faucet.
Anyway, the moral of this story is to avoid the "might as well" syndrome.
It has a way of quickly spiraling out of control around that place! :)
Put the conduit in one of the *front* corners of the closet. Nobody will ever
know it's there -- who goes into a closet and then turns around to look at the
Conduit is cheap. Don't skimp. Use a big one. Like three inches.You may want
to run more circuits later.
If you're just really set against using conduit, you could build an actual
chase with studs and drywall... but conduit's a *lot* cheaper, and faster to
Doug Miller (alphageek at milmac dot com)
Greenlee makes those 6 foot long bits that fit in a standard electric
drill, plus they sell extensions for greater length. The bit has a hole
in the business end, drill thru, attach wire and pull bit back
retrieving wire too.
I once went thru about 12 feet into a closed space above cabinets.
they work great
Thanks! I was wondering if they had extensions or not. A bit and an
extension would probably let me reach from the attic down to the basement.
I'll have to see what is available on my next trip to the store.
The extensions are the same 1 foot extensions that work with spade
Not only are they six feet long, they are flexible. there is also a
tool that goes into the wall to help you point the bit the way you
want it to go. It has never been useful to me. The times I've tried
it, I've found it not very good.
There might be long drill bits that are stiff. I haven't seen them.
It would have helped me in a situation something like yours. I was
in the attic lying on my belly, with my arm into the stack around the
heating ducts (new house) and with my arm and an extension I could
reach the middle of the stack where there was a sheet of plywood, a
fire stop I guess. Because the bit was flexible, and dull from use,
it was hard to drill the hole, but eventually I got it through.
But flexibility has other advantages, like the ability to start
through a hole in the sheetrock and drill down to the basement.
Or the ability to start in the basement, and go in a bit above the
foundation, then up the wall.
I did this once, aiming for just to the left of the hall and front
door light switches. Unforunately it's very hard to control direction
from there, so I drilled into the bottom of the platic box, and ripped
the wire out of one of the toggle switches. Heh, double insulated
drills are great to have. The whole basement went dark when I blew
the breaker in the hall. But the second time I tried, I hit the
right spot, for my burlgar alarm touch-pad to panel wires.
(I couldn't have drilled this hole down from a hole in the sheerock,
because the new hole for the touchpad was going to be right above the
lightswitches, and I didn't want to take the lightswitches and their
box out.) If it had been someone else's house, maybe I would have
done things differently, but I don't know how.)
That's kind of what I was thinking. Easy to install, and basically out of
Inside the wall is my first choice, the conduit my second, and building a
chase in the closet was my third backup plan.
Unless the first two options don't work out for some reason, I'd rather
avoid having to do any sheetrock, taping, painting, etc. I have enough work
to do already. :)
By the way, my in-laws currently have one or two electrical outlets per
room mounted in the 8" high baseboard. I'm planning on adding a few more.
Are there any codes that would prevent me from locating additional outlets
in the baseboard? I'm concerned that trying to cut holes for outlets in the
plaster/lath would turn into a big mess of crumbling plaster. Cutting holes
in the wood baseboard would be a lot less destructive, and simplify access
from the basement.
Eww, and I thought our knob and tube wiring on the INSIDE was bad
Lots of good advice already. We're almost done doing our 80 year old
house without opening any walls, so I'll add a few things we've
- Find your main vent stack. If your house is like ours, you may well
have a TON of space around it to run wires through. We tried several
other approaches to getting wires from the basement to the attic
(through two stories) before wising up to this one.
- Cutting into baseboards is often easier than cutting lath and
plaster. (Even when those baseboards are OAK!) Our lath and plaster
doesn't come down much below the top of the baseboards.
- Pulling baseboards and/or crown moulding off, running wire, and
reassembling is relatively easy. You will spend a bit of time with
putty and paint after you put the trim back, but it's much easier than
patching lath and plaster. (Pulling down the crown moulding allowed us
to wire the ceiling lights on the first floor without using surface
conduit or making huge holes.)
- We got very little use out of the long flexible drill bits, but tons
of use out of the 18 inch (or longer) -rigid- drill bit extenders.
Those are great, since you can swap out bits as they get dull, and you
can use a couple of them together while working in tight spaces where a
longer extender wouldn't fit at all. Most of our interior walls had
firestops at about 5 feet from the floor.
- Fish tape is ok, but fish sticks are better unless you need to take a
bend. Either may get stuck on the keying inside lath and plaster
walls, but fish tape is especially evil in this regard. I understand
it's great in conduit, but we did very little conduit.
- Pull with gravity when possible. (Pull from attic from outlet box,
not from outlet box to attic.) Pull with a partner whenever possible.
One person pushes the line into the space you're pulling through, the
other person pulls out at the end, keeping light tension on the line at
all times, to prevent getting hung up on lath and plaster keys.
- Dental floss with a small weight (like a nut) on the end works better
than fish tape as long as you're working with gravity.
- We also used about 15 feet of flexible, skinny chain. You can drop
it down from the attic and as long as some of it hits the hole in the
mid-wall brace you've just drilled, it will fall through to the outlet
- If your chain sticks to a magnet, you can attempt to catch it with a
small but powerful magnet connected to a fish stick. This worked much
better for us than trying to get two fish tapes to hook, but sometimes
it just didn't work at all, if there were nails, etc in the space we
were trying to fish through.
- If you've already got knob and tube running through your joists,
consider using those holes (after removing the porcelain inserts) to
run your wires, rather than drilling new holes and further weakening
Hope that helps! :)
My in-laws house is a real mess when it comes to wiring. From what I can
tell the original house probably had a single 120V drop for lighting. At
some later point the house was "upgraded" to 240V to support the electric
range. Then a variety of subpanels were added over the years as additional
appliances were added. The back porch had an assortment of electrical boxes
including a large EXPOSED knife switch, a small fuse panel, and a couple of
small breaker panels. Wiring ran all over the wall in various forms
including knob and tube extensions, metal conduit, cloth covered romex, and
a piece of modern romex. A virtual museum of electrical technologies. :)
I posted some pictures of the old wiring on the back porch at:
I'm happy to say this mess is all gone now that I have the new service
The knob and tube wiring on the side of the house was the real surprise.
Comes out of the wall in the attic, runs down the side of the house, and
then back into the basement. The insulation was clearly not intended for
outdoor use, as it has mostly crumbled and fallen away. A quick check with
a meter and tracing the wires confirmed those outdoor wires carry the full
power for every outlet in the living room and bedrooms. So I still have a
fair amount of work to do before I can remove those wires from the side of
Not an option. It's only 2" and on the outside of the house.
My thoughts exactly. Since they already have outlets in the baseboards, it
would be nice to have the new outlet locations match the old ones.
No crown moulding in their house.
The knob and tube wiring is all surface mounted along beams in the basement
and the tops of the ceiling joists in the attic. The only exception is
where wires run up through the floor to an outlet.
I'm drilling holes for the new wiring and moving everything up into the
joist bays. Though we have no plans to finish the basement ceiling, this
would allow that and gives the wiring a bit more protection.
As another poster mentioned, this is compliant with the NEC, so the
only issue would be some additional local code. I did this in my
house with 1x10 baseboards. It gives you an extra 3/4" of depth, so
the really deep boxes will fit in a 2x3 interior wall. It is also
easier to cut the wood neatly than to cut the plaster neatly.
My method was to use a rotary cutter (rotozip) set to the proper depth
to cut out the baseboard. I made a template that I could just nail in
place and run the rotary cutter around the inside. After cutting out
the plaster, I mounted an old work box to the baseboard with
screws--if you want to use plaster ears, you need an old work box with
extra long screws on the plaster ears because of the baseboard
thickness. Then I had to use "midsize" faceplates to provide proper
coverage of the box and screws.
You should check your updated NED for the code-approved height of new
receptacles. Installing receptacles in old baseboard openings does not meet the
new floor-to-receptacle requirement. You MAY be able to get some type of waiver
but this would have to be issued by your local municipality. I redid a 3-story,
4-unit, 120 year old property. Thank goodness it was a balloon-framed structure.
I was NOT permitted to re-use openings in baseboards. There are ways to install
boxes in plaster and lathe so as to secure the un-keyed plaster. Best to find
old studs and purchase old work boxes from Madison electric for the install.
These plastic boxes are code-approved for drywall screws that are INSIDE the box
and easily install to studs. Wall damage is therefore minimal. This way the box
is secured on the stud and there is no worry about the Carlon old-work box
'wings' that do not usually hold up. Wire box before attaching to stud. Not
approved for MC and MC installs are much more difficult but safer in narrower
walls or homes with a lot of rodent activity.
On Saturday, July 11, 2015 at 3:44:05 PM UTC-4, Doreen wrote:
espically since this topic is super old, dating back to 2006
i hope google never sells auto drive cars, since they will try to drive on non existent roads.
they should be ashamed at how bad the truly are
I have done this twice. The first one was knob-n-tube. I will
never fish thru an exterior wall again. So I run the conduit
up the interior walls and all outlets and switches are on the
As for runnig conduit to the attic, the closet is the I would
do it. I ran the conduit thru the corner of the closet nearest
the door and inside a PVC pipe that went through both floors
(first floor and attic floor.
Also where I have seen knob-n-tube, the meter has been inside
the house. Almost everywhere code is going to call for the
meter to be outside. And as soon as you do that, you will an
electrician to pull a permit and to inspect and approve your
wiring. I learned that after-the-fact when the meter reader
saw the changes. Fortunately I found a cooperative contractor
(35 years ago). He liked my work.
There's no insulation in my in-law's house, so fishing wires to the outlets
from the basement should be no problem. As long as there's no blocking in
the wall, the switches won't be too bad either.
It's the full run from top to bottom where blocking is involved that it'll
be an issue. I'm "hoping" the interior walls don't have the blocking, but
haven't had the chance to check that out yet.
Seems to be the overall favorite... :)
I already have a permit, and the new panel and meter have already been
inspected and approved. It's just a matter of updating all the individual
The current knob and tube wiring has everything on ONE circuit. :)
I went up into the attic, and dropped a plumbing snake down along the waste vent
pipe. This, with a little work, went through all the way to the basement. I then
wire, and additional pulling cord through. I probably ended up with 6 or 7 12/2
with no big problem.
Then it's just a problem of running wires from rooms to the attic.
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