Noticeably leaning poured concrete wall -- curious about likely developments

[Frank L. Bartlo]

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.

[Jamie R. Wilks]

Regarding the following comment or notes from your original post:

"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? "

No one, not even a structural engineer, will be able to predict how long before serious major structural concerns develope.

All you can do is note or list the concerns you did observe, and recommend further evaluation and-or repairs.

Anyone who claims they can predict how this home will be effected in the future is either a liar or thinks way too highly of themself.

[Frank L. Bartlo]

Thanks, Jamie. That's what I thought, and I did include a comment to that effect in the advice to consult a structural engineer, with almost the exact same wording about the unlikelihood they will even be able to predict what it will do... aside from the last sentence.

[Robert J. OConnor]

Originally Posted by fbartlo

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?

Thats a very difficult thing to assess sometimes without doing a careful evaluation and running some calculations to determine if the wall is close to failure. Sometimes movement will continue over a period of time before failing, and sometimes it's hanging on by a thread and one unusual event can lead to failure.

The big things here are wall bulging combined with horizontal cracks, which are very serious and can lead to sudden foundations failures. Attached is an example of a similar case where it was left for a while, and then just suddenly failed. They got lucky that it didnt also lead to a outside frame wall collapse.

Good call.