I purchased a home a few years ago and this spring I had water enter the corner of the basement. I noticed a crack in the cinderblock foundation in the outside corner where the water seemed to be coming in. I have now dug down about 18 inches and I have found that the top corner cinder block (First block under the wall plate) is all cracked and a chunk missing on the inside corner where the water was entering.
The broken block is loose and I can pull out large chunks of the block and as I mentioned i see a large piece (3" X 5") is missing along one side that is under a sunporch which couldn't be seen from outside.
I think the water has been entering through the cracked block and the missing area and then the water was filling the blocks on both adjacent walls and eventually entered the house at the floor joint. However, I do not see any cracks in the foundation wall further down so it appears that the wall was either impacted with or water has gotten into a crack and caused the block to break.
In the spring I also could see water on the inside of the block in this corner starting up at the upper wall plate so I think this confirms that this is the entrance area.
Considering the broken block and water infiltration I think the wall must be repaired. Can I take out the balance of the corner block and simply cement in a new block? Do I need to support the house corner or brick veneer while I do this? Any suggestions would be much appreciated.