I plan to finish part of the basement in an older home, but I've come
across something I don't understand that was probably done during a
renovation. I need advice before I can proceed.
The renovation involved a sink/dishwasher drainpipe (PVC). It travels down
about an inch from the basement wall, and then into the floor. You can see
where a trench was made in the concrete floor to hold the pipe. The trench
and pipe have been covered with new concrete.
This spring we had a bit of dampness from seepage (an outside drainage
issue, I think), and most of it dried up in a week or so. But between the
pipe and the wall at the basement floor, the dampness persisted. The
concrete there was also lumpy and ugly. Finally I dug it up; it turned out
to be a patch of crumbling concrete, very sandy and easily broken.
I excavated down about an inch and a half to the original concrete, which
is still in good shape. The rotten stuff is all cleaned out now, and I
plan to put in some epoxy cement and then some patching cement. But here's
what I don't understand: at the edge of the trench, about two inches from
the wall and about six inched from the pipe, on the upslope of the
basement floor, there is a hole, about an inch in diameter, right through the
foundation to the earth below.
I'm sure this hole has nothing to do with the drain as such, because I
ran water in the sink and not a drop of it appeared anywhere in the
excavated area. I could hear it going through the pipe, but there was no
leak from the pipe.
Why is the hole there, and what should I do about it?
"For it is only of the new one grows tired. Of the old one never tires."
-- Kierkegaard, _Repetition_
James Owens, Ottawa, Canada