Yeah, clay soil is a beast. Had a similar experience myself—thought I'd save some cash skipping gravel on a small garage build. First big rain, the slab shifted and cracked...lesson learned the expensive way, haha. Gravel's cheap insurance in the long run.
"Gravel's cheap insurance in the long run."
Yeah, I hear ya on gravel being a smart move, but honestly, I'm not totally convinced it's always necessary. I recently did my own DIY concrete patio at our new place—super heavy clay soil here too—and decided to skip gravel altogether. Instead, I spent extra time compacting and leveling the clay itself, then laid down a thicker vapor barrier before pouring.
Now, I'm not saying this method is foolproof or better than gravel every time...but so far it's been through a pretty rainy season and hasn't budged or cracked yet (fingers crossed!). Maybe it depends on how much prep work you're willing to put into the soil itself? It was definitely more labor-intensive than just throwing down gravel, but it saved me a bit of cash and hassle sourcing materials.
Obviously garages and patios aren't exactly apples-to-apples comparisons. Garages have heavier loads and different stresses to consider. But I guess my point is that sometimes there might be alternative routes if you're willing to dive deeper into prep work. Clay can be tricky for sure—I've heard some horror stories like yours—but maybe it's not always the villain we make it out to be?
Either way, appreciate you sharing your experience...it's good to hear what worked (or didn't!) for others before jumping into bigger projects myself.
Interesting take on skipping gravel altogether. I've been debating this myself since we're about to pour a slab for a small workshop in our backyard. Our soil is pretty similar—heavy clay that turns into a swamp after rain.
"Maybe it depends on how much prep work you're willing to put into the soil itself?"
That's exactly what I'm wondering. Did you rent a compactor or just go old-school with hand tools? I'm leaning toward gravel mainly because I don't trust myself to get the clay compacted enough by hand, but renting equipment adds another layer of cost and hassle. Curious if anyone else has tried compacting clay manually and how it held up over time...
I've tried compacting clay manually before—honestly, it's tough to get consistent results. Even with a heavy tamper and lots of sweat, I still ended up with uneven settling after a couple years. Renting a compactor might be worth the hassle in your case...
Totally agree on renting a compactor—manual tamping is doable, but it's rarely worth the headache. A few extra points from experience:
- Clay is notoriously tricky since it expands and contracts with moisture changes. Even perfect compaction won't fully stop movement over time.
- Consider adding a gravel or sand layer beneath your slab to help drainage and reduce shifting later on.
- If you rent, go for a plate compactor rather than a jumping jack type—way easier to handle and usually enough for small-to-medium projects.
Been there myself... learned the hard way!
