# Foundation on black “gumbo” soil



## round_rock_ray (Feb 7, 2015)

Howdy y’all, I’m thinking about building a 16x24 cabin on a concrete slab in Rogers TX.

The soil gets really soft when it rains a lot and when the soil is dry you get large cracks in the soil. 

My question is what can I do to make sure I don’t have foundation issues later on? I’ve driving around the area and it looks like builders use about a foot of road base with a concrete slab on top. 

And suggestion or ideas will be greatly appreciated.

Thanks


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## Bearfootfarm (Jul 13, 2006)

round_rock_ray said:


> And suggestion or ideas will be greatly appreciated.


I suspect the way the local builders do it is what it takes, along with managing your drainage to keep water away from the foundations.


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## HDRider (Jul 21, 2011)

I think BFF is right. Study local methods. They have been fighting it, and see how they won.


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## Alice In TX/MO (May 10, 2002)

You cannot win. Period. You can’t affordably build a slab on black gumbo clay that will withstand the heaving. I own several houses in Jackson County, both slab and pier and beam. 

I will post a longer explanation later, but trust me. All the slabs flex and shift. All the pier and beam houses have to be leveled every few years. 

Call the local house leveling company and ask the question you asked here. They will have the most experience. 

I have built houses and remodeled houses. I asked the same before I moved there. Good luck!


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## round_rock_ray (Feb 7, 2015)

Thanks for info fellas


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## oldtruckbbq (Aug 8, 2016)

I lived in black gumbo land in Texas for 14 years. Seems like every small town has at least one house leveling company, and they stay pretty busy. One of the foundation repair companies even uses (used?) Nolan Ryan as their spokesperson. Doing just the road base and a slab won't do it. Most places use a lot of micro piers throughout the foundation to help support it. Having gutters to keep the water from pooling near your foundation will help prevent heave, but you have to also protect from the drying and shrinking. I knew more than one homeowner that had a sprinkler system to keep the soil within 25 feet of their foundation moist to keep it from drying out and cracking. Even that isn't a guarantee. Like Alice said, it is going to shift and flex, and a pier and beam house will need leveling every few years. Heck, if you buy a manufactured home they will level it when they install it and come back in a year and level it again to account for shifting that will take place.

We rented a pier and beam house for years. My next door neighbor worked for a house leveling company and had all kinds of jacks and tools in the bed of his truck. Once a year I would buy him a case of beer and he and I would go under the house to level it. It wasn't at all uncommon to take out shims we put in last year and move them to a pier just a few feet away.

Even the big construction companies have significant issues. Ask the people who built the $60 million Allen, TX high school football stadium, only to have it suffer devestating cracks and shifting due to foundation issue caused by black gumbo soil.


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## weaselfire (Feb 7, 2018)

Pilings. You have to get below the black clay to stabilize the foundation.

Jeff


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## Alice In TX/MO (May 10, 2002)

Yes, but putting pilings under our house cost $20,000 about 20 years ago.

In effect, we have a house on concrete stilts (pilings), that you can’t see. They extend from the bottom on the slab down through the black soil to a stable geological strata. Thirty four of them.


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## farminghandyman (Mar 4, 2005)

I do not know about black gumbo, when I was in WYo, there as a red gumbo type soil and the people I worked for said they dug down and filled with small boulders, and then filled in with smaller and smaller finishing up with sand and gravel, sound like to me they dug down 6 to 8 feet, but they still had slabs crack,


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## FreeRange (Oct 9, 2005)

This is our 2nd house on black gumbo. Both have rock not far under the gumbo. With the first, the builder scraped all the gumbo down to the rock on half the build site, and filled the slope on the other half of the site with the scraped off soil. The half that was on rock never moved, but the half that was on fill heaved every year. We did not build that house, but bought from the builder.

With the place, we had the contractor scrape down to the rock and fill with select fill. It's only been 3 years, but so far, so good.


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## fishhead (Jul 19, 2006)

I saw homes in Fairbanks AK that were built on permafrost. In order to keep it frozen and stable they would put a 4' layer of gravel and then poured a reinforced slab on top of it. The idea was that the house would just ride any movements like a boat. I would need some built in movement tolerance for water lines and wastewater lines. You don't have to worry about thawing permafrost but it sounds like something that would work on unstable ground.


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