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c/custom-home-buildsmax415max4152mo agoProlific Poster

Watching a house in Charleston settle made me rethink foundation specs

I was helping a friend check out a new build on the coast last year, and we saw the first floor slab had a hairline crack running the full 30 foot length. The builder had used a standard 4 inch slab, but the soil report called for a deeper grade beam. It clicked for me that you can't just copy foundation plans from one lot to another, even in the same town. Anyone else run into this and have a good way to explain it to a client who wants to cut costs there?
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paige86
paige862mo ago
Wait, they only used a four inch slab on coastal fill? That's wild. I've seen slabs like that heave two inches after one wet season because the soil just turns to soup. You can't fight soil reports, they're basically a weather forecast for your dirt. Trying to save a few grand there is like skipping the frame on a car to get nicer seats.
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andrew_rodriguez
That four inch slab story is a perfect example. @theajackson is right, the soil report tells you what's coming. Trying to save money there just guarantees a bigger bill later.
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theajackson
Yeah, that "weather forecast for your dirt" line is perfect. I saw a patio slab pour on what looked like solid ground, but it was just a thin crust over soft clay. The whole thing cracked like a spiderweb in three months because they didn't dig down and put in a proper gravel base. The soil report is there for a reason.
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