I have a 1970s home with aluminum siding on the main floor and parging on the basement/foundation. Where they meet there's a J channel or similar, with one seam in the middle of the front of the house that appears to have old caulking on it. We reparged the front, and have discovered a lot of staining appearing to fan out and down from the seam. I am assuming that any water that is hitting the house on that side is collecting in that channel and draining out the seam. I am looking for suggestions on how to correct this. Obviously we don't want the water to get stuck in the channel, or end up in the home, but it would be much more ideal if it wasn't staining the parging.