Hi all, I need some help repairing a joint under the top step of the front entryway to my house. The top slab is actually over the corner of the basement, which is odd, but that's another topic. The issue is this joint between old and new concrete, as seen in the photo below: The previous homeowner is a mason, and did a lot of concrete and brick work around and inside the house. In 1999, he repaired/resurfaced the entry steps. The concrete under the "lip" is actually the top of the foundation. The concrete in the foreground is the second step. The concrete on top is the top step. It doesn't look like it from this picture, but cold winter air is entering the basement through this crack/joint. This basically runs the entire perimeter of the top step...and I know this is happening because I'm getting frost in the basement directly on the other side of this concrete. I need to patch this, asap. Any ideas what will work in the sub-freezing weather? I'll consider anything that is close color-wise...so if something elastomeric or asphaultic comes in "gray", it should work. I just need to stop the air coming in, then I can insulate from the basement side. Your thoughts are welcome. Thank you.