A house I inspected that was built in a location that had notoriously swampy soil prior to development had a reinforced poured concrete foundation that had the worst settling I’ve ever seen in such a foundation.
Using a plumb level, I measured the inward leaning slope at about an inch per 2 feet, which of course is 3 inches at 6 ft of elevation, where there was a horizontal crack observed in one area between 2 basement windows, above which the foundation leaned the other way (note leaning fuse box). Otherwise there was only relatively minor foundation cracking evident, with no indications of significant leakage, and the only other effect observed in the house was leaning of the lower portion of the exterior masonry alongside the basement window near the center of the wall.
Attempts had been made to brace the foundation with metal I-beams that were cemented into the floor – probably with little footing – and wood braces to the 1st floor joists above, some of which had failed (cracked), evidently having been inadequate to counter the force of the freezing and expanding winter soil. This house had been built in the late 1960s, and the reinforcement attempts did not appear to be very recent, judging from the appearance of the materials.
Of course I recommended reinforcement of the walls and a second opinion by a structural engineer, etc., so my question is not what to report as much as just how soon serious major structural effects elsewhere in the house are likely to occur?
I’m genuinely curious, as I’ve never encountered anything quite like this in a reinforced poured concrete foundation in my many years in this business and previously as a renovator and agent.
My gut feeling is that the wall is likely to provide adequate support for several decades, even if nothing is done beyond ensuring good drainage, based on the time frame of this development and my observations of collapsing concrete block foundations, which are rather common around here.
But this is quite a different ballgame, as the wall itself appears to be mostly leaning as a whole, rather than cracked and bowed at a lower point, as block or masonry foundations tend to do.