1950's house block foundation
Hi guys,
History-
I own a home that was built in about 1952. I don’t know all the history, but at some point one of the previous owners had some sort of drainage system put in, in the basement. It looks like they broke the floor up about 12” wide around the exterior walls in the basement, dug down some distance, filled it with gravel and maybe a pipe with holes, then covered over that with gravel and then a coat of concrete. It appears to be connected to the floor drain near the washing machine etc based on the “scar” on the floor from new concrete being put in.
I was attempting to paint one of the bedrooms in the basement and as I was preparing the walls, I noticed that one area was soft. I cut into the wall and discovered that water had somehow been getting in. I removed the drywall from the floor up to about where my sprinkler valves are on the outside thinking there may have been a crack in the foundation, but there wasn’t one. The insulation was wet and the paper on it was black and rotting. So, I then removed the drywall about 20” from the floor and below and discovered an opening filled with gravel on the floor directly under the finished wall and saw that each 2x2 was rotting about 12” from bottom. It appears whoever did the drainage system didn’t remove the baseboard. They just filled in concrete up to it and then caulked it with silicone. Then, I am guessing that water had been weeping up into the insulation etc. I live right near a small stream, and I am guessing the water table is somewhat high for this area.
So, the other day I went to fill in this opening on the floor with concrete, after I had removed the excess gravel, but I decided to check the other exterior wall, thinking it may have a similar situation. The area where I checked was in the same condition, but after removing, again, about a 20” high portion of drywall I discovered that it wasn’t the same situation across the whole wall. But there was a “hole” in the wall that led nowhere. I can feel cool air coming out of it. It looks like a cinderblock at the back of the hole with a space between it and the footing. On the top part of the hole it is wood. It looks like the construction may be this, starting from the inside: drywall, 2x2 with vapor barrier insulation, a concrete coating about ¼” thick, some type of block, about a 1/4th” space, some other block, then—guessing here—some sort of coating and finally the outdoors—either underground or above.
Question-
What should I do with the hole before filling the opening with concrete and replacing the wall where I removed it? And is there anything else I can do, should do to try and keep water out?
Thanks,
Brent