"Rich Wales" wrote in message
g...
"krw" wrote, regarding my mom's 50's-era house:

As Jim said, I highly doubt it's K&T. My parents
built a house in the '50s with NM. Some regions of
the country still required BX though.

When I looked behind the receptacles in my mom's house, the two
wires in each box had white and black plastic insulation, and
each pair of wires looked like it was covered with some sort of
non-metallic, black outer layer that seemed to be impregnated
with a tar-like substance. The outer layer appeared a bit on
the brittle side.

I took a look under the house today (peering into the crawl
space), but I didn't see any electrical wiring there at all
(except for phone and cable TV). I imagine this may mean that
the electrical wiring is in the attic; I haven't tried looking
there yet.

Sounds about right- in a 1-story house with a crawl, much easier to do the
rough wiring from above after the house is weather-tight, but before the
interior walls are rocked or plastered or whatever. Crawlspaces suck, for
the tradespeople. The cable description sounds spot-on- fabric covered
romex, and yes, that outer sheath is brittle, as well as the copper ends of
the cables around the terminal screws. And if you live in an area that
required (at the time) that the romex be stapled to the studs, don't count
on there being any slack to lengthen the wires folded up in the box. Good
electricians try to leave enough extra to change out the devices at least
once, but it doesn't always happen.

Like the others have said- I'd look at pulling new circuits for the kitchen
and bath outlets, with GFCI, and maybe one for whatever passes for the
entertainment center. The other outlets, I'd replace with fresh 2-holers
(yes, they are still available). If your mother is into gardening or
whatever, a couple GFCI-protected garage/outside outlets are also a good
idea. If the service panel has enough capacity, even if it is screw-fuse, as
long as it is in good condition, it is probably safe to leave. But if you
have an electrician coming in anyway, I'd get a price on a new panel of at
least 150 amps. A trick I have seen used in houses like this, to minimize
crawlspace pain, is to run a feeder up to the attic, and then put a
sub-panel right by the access hole in the attic. You then snake the modern
wires down into the walls as needed. Still a PITA, but a lot easier than
trying to locate the walls and stud cavities from below with poor access.
Outside walls are of course the hardest, due to lack of headroom, and
insulation in the walls. When you call around to electricians, tell them you
are looking for someone with experience in 'old work' situations. They will
know the tricks to doing it safe and legal, with minimum damage to existing
interior.

I got lucky on this 1960 house- the romex has a ground wire, and the boxes
were grounded, so all I had to do was switch the outlets. The ground is good
enough to get a green light on the meter.

aem sends....