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Foundation Stabilization and Repair/24 Ft. Diagonal Crack in foundation spanning 4 walls




  My family and I have just moved in to a duplex house (One house joined to the other, with one wall shared between the two). Itís in Madison WI and at a guess was built in the 80s. Thereís a long continual diagonal crack in the foundation that Iím concerned about. Itís 24 ft. long and spans multiple walls. The pictures show this in better detail.  

The crack has been sealed and smoothed with some form of filler at some point, so itís hard to accurately gauge how wide the crack is. The walls that the crack runs through are flush and smooth on either side of the crack, above and below it, with no bowing in any of the walls as best I can tell.

Iím not an expert on the structure of foundations by any means, but have done some reading on the causes of diagonal cracks, and nothing that Iíve read provides an explanation for diagonal cracks of this consistency and length. How much of a concern is a crack like this? Is there a danger that a foundation wall could collapse without any sort of warning, or would there be warning signs first before something that catastrophic happened?

Thanks in advance for taking the time to reply.

     Because there is no wall displacement, and there appears to be no other cracking or movement, I don't believe you have a serious problem here. Footing failure would often result with wall movement and additional cracking. Unless you are on a hillside wall movement on 4 wall surfaces is unlikely. If there was any foundation settlement you would see cracking / drywall damage and door frame / window opening movement/ or binding transferred upward upstairs.
     Hydrostatic soil pressure is not a factor here as this is a common basement wall between you and your, I suspect what you are seeing is the result of a cold poured seam, where one batch of concrete mix was added on top of the previous pour before it fully cured. This type of cold joint is usually more obvious because the concrete batch colors often vary slightly. In this case it's almost a perfect color match. Quite possibly two truck loads from the exact same batch were poured...with a time delay between the pouring, which would create a seam in between the two pours. This often leaves a line / crack. It appears the concrete was poured at the high side of the "crack" and flowed down , around the corner , to the low end. The imperfection was then buttered up to make the wall smooth.
     If rebar was installed in the wall there should be no problem with wall failure. Since there are no lateral loads involved here, settlement would be your only worry...and I don't see it from your pictures.
     However...When in doubt, bring in a structural engineer !   

     Best regards...Jim    Cleveland, Ohio

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Jim Hise


I am the owner of EXPERT BASEMENT REPAIR in Cleveland, Ohio. see WWW.EXPERTBASEMENTREPAIR.COM for more helpful links, pricing and information on repair work and products I can identify the reasons for movement or cracking in home foundations, basements and walls. I am familiar with most waterproofing and water control methods. I am familiar with and have installed Ramjack, Dixie MacLean, and A.B.Chanceô helical and push pier systems, including tiebacks, steel beams, and rod and grout repair and also several carbon fiber stabilization products. I am currently certified for Fortress carbon fiber installation and have performed carbon repair in the greater Cleveland and Northeast Ohio region for 14 years. Please remember to tell me what city you live in to help me answer your question up front!


20 years of structural foundation fault identification and most repair and stabilization methods. I introduced Fortress carbon fiber to this region of Ohio 14 years ago. I am always on site and involved in order to monitor each project I am responsible for. I have seen high pressure sales tactics used on homeowners over the years to buy on the very first contact. The most dominant ads on this site are good examples. My experience is that you need to be very careful when having these companies in your home.

Waterproofing magazine issue #2

Associates degree...and the school of hard knocks! Formerly certified by A.B.Chance company from 1993-2005. I have a construction and home improvement background for almost 35 years. I bought, restored and resold distressed property. I worked with 4 different foundation repair companies and am familiar with most methods. I also worked for a waterproofing company for several years. I teach ongoing education classes for home inspectors, adult education and Realtors in foundation fault identification and repair.

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Hundreds of residential, commercial and some industrial.

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