Suggested Repairs for House Split in Half, Caused by Foundation Issues

[czarSS]

Home Foundation Split Along Middle Causing Cracks All along

Please respond to this if you've ever experienced an issue similar and have been successful in addressing it, or if you have advise on how to address it.

The home you see in the photo has several foundation issues. The main issue started on the east side of the home where there are two AC drains, which i have reason to believe initiated this issue. These drains were draining onto, possibly, expansive soil on the side of the foudation where the issue started. The crack is approx. in the middle of the home and runs along the entire home. The initial lift most likely cuased a leak in the plumbing causing more expansion, it odd that the crack happens along, it seems like the sewer line, It runs along two toilets.

The crack, as seen in attached photo, supports the fact that there was lift in the area directly underneath the crack. For the most part, the rest of hte foundation looks pretty solid. Expept for the poor paving around the home, which has caused all kinds of issues with the driveway - settlement, all the driveway will have to be replaced.


This home is two storeys and has developed stress cracks in many locations other than the direct areas along the crack. I know that when a certain part of the foundation sinks you can elevate it back to original height using piers or install a type of hose draining at low pressure, this hose will act as an moisture content equalizer, if foundation has sunk it will cause the soil to expand causing foundation to elevate.

Just not sure how you address an issue where the the home foundation has split in half, and the most logical reason is water/moisture leakes along that line onto expansive soil. I'm sure it is a monolithic slab, so i dont this there is an expansion join along the crack.

 

[XR250]

http://en.wikipedia.org/wiki/Caterpillar_D9

:>

 

[EngineeringEric]

Is underpinning and excavation below a depth (deemed appropriate by Geo) and filling with non-shrinkable out of the question? Helical piers and supporting the entire structure since all the soil is capable of shrink-swell? the crack in the photo does not appear that drastic, so i don't think this is a issue of the house is falling down yet.

In terms of process, i would determine if it really is expansive soil, could be done with hand auger and testing. If not underpin/support sinking foundation. if it is expansive then possibly underpin below wet-dry cycle soil or post a question to Eng-Tips for other alternatives.

 

[a2mfk]

You need to start with some soil testing to determine if you have plastic soils, and how plastic they are (Atterberg test). 10ft hand augers would be a good start, one at the crack, and a couple more in other areas of the house for comparison. You never want to start a foundation repair project until you fully understand the subsurface conditions, and plastic clay soils can be particularly tricky to deal with.

 

[czarSS]

Thanks EngineeringEric, underpinning is definitely a viable option. I would have to cut a sections along the foundation out, along the crack first, but thats not problem because i'm certian that there are plumbing issues as well.

I just don't see any way around it than to remove the bad soil out from under the crack. Unless installing a water well and lowering the groundwater table will work.. to remove moiture out of the soil.. what do you think about this option?

 

[czarSS]

Absoa2mfk thanks for the reminder, thats exactly what i need to do first. The home was built back in 1989, so I'm sure there are no records of the site prep and foundation.

ExcelEngineering- Are you suggesting that the property needs to be leveled? If so, I appreciate your concern, but I know for a fact that there is some kind of solution out there for this, just need to find the more appropriate one.

Please keep the suggestions coming..

And thanks everyone in advance.

 

[a2mfk]

Be very careful with partial underpinning of a structure on expansive clay. It can cause more harm then good, depending on the structure and soil conditions. I have first hand experience remediating failed underpin repairs.

 

[theonlynamenottaken]

For a very first step why not install crack monitors and take precise digital level measurements? Armed with the knowledge of whether the movement is currently active, and data on rate vs magnitude, you'd have a solid foundation (pun intended) for designing repairs when combining that info with soil testing results. Crack monitors, or even caliper measurements across indelibly marked spots along cracks, are very cheap and can yield very helpful information about a moving structure.