I noticed some water damage to the carpet and trim in the corner of a
basement room that corresponds to the SE corner of the house and
decided to investigate.
The house was built in '57. The foundation is essentially a simple
rectangle built of cinder-blocks. The basement floor is poured
concrete. The room was drywalled and the floor had trim all around so
I didn't have a view of the cinder-blocks or the floor in the area of
the water damage.
Pulling away the trim, I found the oddest thing: for about 5 feet
along the south wall and 20 feet along the east wall, there is about a
1 inch gap between the floor and the cinder block. Also, it looks
like when they poured the floor and smoothed it out they just kind of
shoved the excess concrete over to edge of the floor and left it there
to dry as a rough, uneven, unsightly, "lip" protruding up from the
floor. This lip does not exist anywhere else in the basement, only
where this gap exists. Everywhere else there is a nice smooth seam
where the floor meets the cinder-block.
FURTHER, underneath the corner where the cinder-blocks intersect (and
from whence the water damage seemed to be eminating) there is a
cavity, probably about 6 inches deep. Shining a flashlight down the
hole I could see a half inch or so of standing water. Poking around
in the gap further away from the corner, I found that it was filled
with pea gravel. I cannot tell how deep the fissure is or how it
"bottoms out". All along the wall where this gap exists the dry wall
was obviously water damaged and crumbling and needs to be replaced.
I cannot for the life of me figure out what the builders were thinking
when they did this. Could there be a purpose for this gap? Drainage
maybe? I'm trying to re-paint and re-carpet the room and would like
to fix the water problem before I do so. It seems obvious to me that
what is probably happening is that somehow water from the outside is
getting in the gap and when the ground outside is very wet the cavity
in the corner fills up and overflows onto the floor. One thought I
had was to get some of that expanding spray foam stuff to spray in
there to try and fill it up. But I worry that if this is some sort of
drainage system, I might foul something up. Also, that probably
wouldn't make a perfect seal everywhere and it might end up making it
worse because then all I've done is make the reservoir smaller, thus
causing it to overflow more often.
Anybody have any ideas?
Also, for what it's worth here are a few more clues:
1) I have big-time drainage problems in the back yard (to the east).
It's probably been that way since the house was built. The problems
generally don't tend to occur near the house but the soil does get
very wet there too. I dug some post holes close to the house not long
after some heavy rains and they kept filling up with water for a
couple of days.
2) I said the foundation is a perfect rectangle. That is not
completely true. On the east side there is a 2 ft section where the
cinder blocks jut inward 6 inches or so into the basement.
Interestingly, to the south of this point is where the gap and
rough-edged floor begin. I can't tell what purpose this inward
deviation might serve. There is nothing going into it (like a pipe or
something) from the joists above. And I don't see any corresponding
deviation or fixture on the outside of the house.
There's more but that's probably enough for now! Any help
Thanks in advance,