Sinking at basement perimeter in large 1920s house

Large (about 3000sf) c.1925 house with a brick basement foundation had noticeable basement floor cracking and sinking evident along the perimeter and the base of the chimney below the fireplaces. One of the foundation walls was also bowing outward, toward the yard (last pic).

This was consistent with sinking of the foundation and chimney walls. The concrete basement flooring was evidently rather thin, not more than about 2 inches. The sinking appeared relatively symmetric, as there were no cracks that were very wide or had significant elevation differences, the worst of which was shown on the third pic. There were only indications of slight seepage. There had been scattered recent thunderstorms in the area, and the area probably had a shower the previous evening.

The yellow brick where 2 of the pics were taken was a decorative veneer, not the foundation wall.

Also, cracking of the exterior masonry was observed, mainly near some windows, which was consistent with sinking on the sides of the windows, rather than above the lintels.

The house was built about a block from a large river, but no noticeable signs of soil erosion were observed. The downspouts were, however, run into sectional ceramic storm drains, which may have caused some erosion from soil having been drawn into the drains. There were some tall trees, but none very near the house.

Overall drainage was to the front, and the grade was mostly level in the rear, though a slight depression was observed on the driveway side near the wall that was bowing out to the yard.

Obviously there has been some unusual foundation movement, but how serious is it really?

My initial thoughts are that this was most likely due to poor soil preparation upon construction, the house has been standing almost 90 years, has probably settled into place, and is unlikely to change much in the near future, though re-direction of the downspouts and improvement of drainage and grading in the rear would obviously be advisable, and complete elimination of seepage would likely be difficult and expensive to accomplish.

Thoughts, anyone?

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From the photos it looks like you might have case of uniform settlement. In most instances of uniform settlement, the structure settles uniformly and causes minimal damage to the structure. In this type of settlement, foundation cracks may be minimal or may not appear at all. Even so, if the house is “uniformly settling,” you should still recommend it be checked by a professional engineer who can tell you if the house will continue to settle uniformly and if the the integrity of the structure is at risk. Often the biggest risks with uniform settlement is stress on the utility connections such as gas, electric and plumbing.

That makes perfect sense, John, thanks.

“Obviously there has been some unusual foundation movement, but how serious is it really”

I’m not clear about what your perspective is here. Are you attempting to establish if there is a serious problem with settlement or to minimize what are obviously serious problems with site conditions and possibly structural failure. In 1925 there would have been little else other than experience dictating building methods as there were few municipality’s governing building standards as codes were non existent. An evaluation from a soils engineer and a structural engineer would be warranted given what I see.
A Nachi buy back program might also be a good idea. The photos are documented red flags and should not be minimized by any means.

NACHI buy back program? I’m not familiar, will do a site search.

My objective is to do my best to provide the best information possible for my client to make a wise decision on house they like, while being fair to the sellers. That’s why I posted this here.

I will recommend they consult a structural and/or soils engineer, and in fact had said this is tricky enough that a 2nd opinion from a specialist would be advisable when we went over the findings. But they weren’t paying me to simply state the obvious and pass the buck to somebody else without providing any analysis or insight of my own.

Sounds like you may have too many objectives. Your duty is to the customer who is paying you, I believe. If you have an interest in the property I would not recommend you put anything to paper as it would and can, and will be construed as a conflict of interest… Don’t you think?
Fairness is a duty you have at all times… Objective professional opinion is also the operative word here.

My client did bring in a structural engineer, whose take was very similar to my hypothesis. He pointed out that, being near the river, the soil was mostly fill, and had settled from the weight of the structure. He said it was highly doubtful it would settle much more in the foreseeable future.

Another stroke of luck (pertaining to the inspection) was that we had historically heavy rain in the area the day before his inspection, so we were able to get a good idea of leakage issues. Turns out there was hardly any seepage, and the basement was quite dry, despite a flooding emergency state throughout much of the metro area.

So my client has a report from a structural engineer as well as my report to document the condition of the house at the time of purchase and the likely prognosis to keep on hand lest he have occasion to sell it in the the future.

I don’t see where any interest in the property could be read into my posts, unless that was just an aside for my information. I certainly had none, only an interest in providing the best possible service to my client. And the structural engineer said my report was the most thorough and informative of the many he’s seen.

Keep the perspective of an 89 year old home in mind… what you are seeing today, may have occurred after a historic flood of the river 50 years ago.

Yes, Jeffrey, always a good thing to keep in mind when inspecting older homes. Often things like sewer systems have changed, possibly more than once for such an old home. Some in the 'burbs even had septic systems when they were originally built and “out in the sticks”.

I remember when the city sewer system got updated where I grew up, and that took care of the basement flooding that was a frequent hassle. Now in this latest deluge, other cities where they didn’t have such problems back then were the ones in which the basement and streets flooded… for the first time since most of the houses were built!

Appreciate the responses, everyone. Learned a lot about structural inspection from this one.