Unusual Footing Crack in Crawlspace

I ovserved an 8’ long horizontal crack at the side of the foundation footing in the crawlspace. The crack was 1/2" wide at its widest. The foundation wall above the footing was about 40" high and had no cracks or signs of movement. This is a two story beach house. The rest of the foundation looked great. What caused the crack? Corroded re-bar? 1979 2 story home.

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Possiblity of no rebar. Is the footing below the frost line? I took a three foot piece of ground rod and made me a pipe handle to probe under foundations and top of septic tanks.

Given the construction date and the excellent health of the rest of the foundations, I would be very surprised if there was no rebar in the footings. Frost line is generally not an issue in this part of the world. The climate is very temperate. The footing depth requirement here is 18", and this home met that requirement. I have never seen an instance of frost heave here.

I have seen a whole lot of foundation cracks, but not one quite like this. It is a large crack, but it is in a location where I don’t think it will cause any significant problems. The only thing I can think of that may have caused it is rusted/expanding rebar, although the crack is not particularly straight. Ayone have any other thoughts?

Why the difference in concrete color? If this were a cold joint and there had been some settling, the lower section might have dropped a bit and it might look like that. Was it only 8 feet in a much longer wall?

I agree–possibly a cold pour to level the footing

Cheers

Definitely not a cold joint. Yes, it was only 8 feet in a longer wall.