Sealing a foundation crack or stabilizing it
Sealing suits a small crack that has stopped changing, because it can keep water out and make the crack look better. It won't hold up a foundation that's still moving, though, so if your crack keeps changing, plan on a repair that goes beyond sealing. I'd rather tell you a crack is cosmetic than sell you piers you don't need, and I'd rather tell you it needs more than a patch than seal it and walk away.

