I was called out to look at a 100 year old foundation that had cracks and water seepage. The first photo taken outside was at a corner crack. Second photo taken in the basement showing patched foundation cracks. At first glance you would think that was a concrete foundation. Turns out what appears to be concrete was only a plaster type parging. Fortunately I found a section of parging missing at the base of the foundation wall in the basement where the wall had sheared off and shoved inward about 2 inches. The third photo shows the foundation was actually structural clay tile shown in photo four.
The home inspection report the buyer gave me said this about the foundation:
Minor damage and / or minor structural movement was noted at the foundation. Make sure the downspouts and grading are shedding water away from the home. Monitor for continuous movement. Have further evaluated by a foundation specialist @ your discretion as cracks appear to be typical and or minor in nature at this time.
Its not my intent to bash the home inspector, but to take the opportunity to educate other inspectors looks can be deceiving.
what was Your repair recommendation Randy?
Thanks, Randy! Great education for many of us.
You cannot tell easily from the outside but you can from the inside by the parging alone. I have never seen a poured concrete foundation when it’s parged the way pictured in the second pic. It’s always stone, CMU, brick, or some such. BTW, there have been a few posts on here about similar clay units used for a foundation… Never seen it in person, however. I think they were used in dryer areas of the country.
It’s important to get a good look inside where possible. I’m suspicious when the foundation wall outside appears to be wider than what sits above, especially around here where a lot of coating is applied to hide cracks and even shifting sections of concrete pour. The applied material can get stupid thick sometimes, as if it wouldn’t be noticed.
Unfortunately with all the wall cracks and shearing at the bottom water entering the hollow tile could travel just about anywhere. The soil type is mainly silty clay loam with a seasonal water table 12" to 30" below the ground surface. The soil survey also lists this soil type a very limited for basement foundations due to soil wetness and shrink-swell potential. The best solution was to temporarily support the house and pour a new basement wall. Pouring a concrete foundation wall inside the basement to support the existing basement wall was discussed, see graphic below. However due to the brittle nature of the clay tile and high water table you would have to dig down to the footing to try and waterproof the tile. I had concerns exposing a 100 year old cracked clay tile wall would buckle without the soil support. I saw no easy solution to this problem. It was a no-brainer…buyers walked away.
Pouring new foundation all around from inside? how much does that cost
Never got past the concept stage on this house, but it would be labor intensive and expensive. Plus due to space limitations a concrete pumper truck would be needed $$
In my area of Minnesota, the house would be raised and the entire foundation replaced with a CMU foundation. Sometimes a poured concrete, but that would be rare.
I have only seen structural clay tile used in old German communities in central Missouri that settled near the Missouri river. A lot of brick houses in the region also. Based on my inspections and from observations the Germans had some damn good brick layers and carpenters. Just look at some of the German Catholic churches in my area.
@rmayo That’s fantastic. Imagine the weight their foundations support. Very impressive.
Yeah, I could see it raised and replaced. My grandfather used to do that in Washington. Didn’t take much of a lift to get the space to work. His focus initially was making sure the house didn’t come down before it was supposed to.
I relocated from Washington to Minnesota back in 2006. In August 2007, I saw my very first structural clay block foundation. It took me a while to wrap my head around these seemingly fragile (think Terra-Cotta flower pots, Ha!) could support a home. I have since seen then used in commercial properties. Unbelievable!!
Here’s a couple of pics from that first experience… (Kinda looks familiar)!
Yeap, marvelous structures… no computers and lasers back then, maybe a pencil and a paper, crazy stuff! Still standing as if built not long ago.
Last one I did looked like this
Oh geez, David, that looks ugly. Was it just one section, or most of the foundation that was crumbling?
Great catch! I normally don’t suggest how to repair things like this but recommend evaluation by the appropriate professional for repair options, in this case, a structural engineer.
Structural issues are obviously one the biggest areas of concern for us as home inspections. So, thanks for the case history account. Even for experienced inspectors, this is a learning opportunity and I have some questions, if you don’t mind. Did the HI mistakenly identify the foundation as concrete?
Your last photo is the smoking gun, but did you see other evidence of this structural displacement before you found the area in the last photo? Did you have to move a dryer or other possessions to reveal the damaged area in the last photo? The wall has sheared and moved 2" at the bottom. Was the parging in the photo still in contact with the wall? Was the edge of the parging also the edge of the upper portion of the moved wall? For instance, did probing under the parging contact the bottom of the sheared construction tile?
He listed the foundation and Concrete/Masonry Block. A section of the foundation wall had been rebuilt with masonry block when an addition was added on in the back, but he labeled the rest as concrete. To answer your second question, no due to stored items and most of the walls were studded out with insulation stapled on. I moved some junk to find it, then proceeded to pull off some insulation with the homeowner’s permission. The wall sheared at a mortar joint and the parging above the shear line was intact.
Randy Mayo, PE
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Randy … So the home inspector would basically had to do some intrusive inspection to get where you got. To a lot of our guys that seems like a no-brainer … BEYOND our SoP, but in the past 15 yrs I’ve seen 2 local KC home inspectors get creamed over something similar and both were good inspectors AND PE’s