I recently bought an older home (50s), the previous owners had a poured concrete front step/porch attached to the front walk. The porch has now settled and a large crack appeared allowing water to drip into my cold room under it. I have tried to fix it with concrete crack compound but this just drips through the crack with the water. The crack is approximately 1/4 in wide-not wide enough for me to put a piece of screening into it but plenty wide enough for water to pour through.
Answer:
Try a single masonry caulking compound but make sure you apply it to clean surfaces.