On 25 Jul 2006 06:41:06 -0700, "z" wrote:


Pete C. wrote:
wrote:

I'm sure this question has been posted and answered a thousand times
here, but a family member who routinely asks me to walk-through homes
she is interested in buying (because, as a walking Typhoid Mary of
Money Pits, I have hard-earned knowledge) has asked me to jump on a
particularly desirable (location, location, location) multi-unit this
AM.

One half of this duplex has knob-and-tube.

I have read conflicting estimates of the integrity and safety of
knob-and-tube on this group and other web sites. But I'm scheduled to
go through the home in two hours and thought I'd post and maybe get
some fresh insights.

From the street, and as far as the exterior foundation goes, this home
is an absolute steal (new roof, great landscaping, has it all). My
family member needs a place to run to as the result of a divorce and
won't be able to take on both the mortgage and a complete rewire at the
time of sale; hence, my post.

Thank you as always for your responses.

The deciding factor is not whether it is dangerous, which it rarely is
unless it's been messed with, but rather whether you can get insurance
for the place with K&T. Most insurance companies are absurdly paranoid
about K&T and indeed any electrical older than about 30-40yrs.

Pete C.

At risk of getting into tinfoilhatland, literally, I'd just point out
that the electrical fields from knob and tube are (I would guess) quite
a bit higher than modern wiring, even without metal shielding, due to
the conductors being further apart. The significant health effects, if
any, I leave to other posters to argue about. (I would also guess it's
not a significant risk compared to fire or not supplying a ground).

Which reminds me; a while ago it was posted here that GFIs don't need a
ground. Is that true? Could you eliminate the ungrounded risk by just
replacing the outlets with GFIs?

No, you need the ground. That's an important part of the whole
system.

And you have the electric field problem exactly backwards. The
widely spaced conductors will carry about half the field strength of
normal wiring. Those two conductors in normal wiring are both
throwing off electric fields.