On Apr 28, 3:02*am, wrote:
On Mon, 27 Apr 2009 19:21:30 -0700, Jonathan Sachs

wrote:
I used to own a house that was built on a stemwall foundation. I
grounded the electric outlets by drilling a hole up through the bottom
plate under each outlet box, pushing ground wires up through the hole,
and fishing them into the box.

I'm now buying a house that is built on a slab, and many of the
outlets are ungrounded. How should I deal with the problem in this
case?

Get an pneumatic air hammer and break out about one foot of concrete
under each outlet until you hit the ground (soil) under the concrete.
Remove the outlet from the wall, and bury the entire outlet and box in
the ground under the floor. *This will insure the outlet is well
grounded. *Then pour fresh concrete over each outlet hole and smooth
it to match the original floor. *


For the locations where running a ground wire would be difficult or
impossible, put in GFCI outlets and forget about grounding them.