That time my DIY shed foundation sank 2 inches after a single rainstorm

I built a wooden shed on gravel in my backyard in Austin last June, and after one heavy thunderstorm the whole thing tilted so bad the door wouldn't close, and I had to jack it up with car jacks and pour concrete pads underneath to fix it.

3 comments

3 Comments

king.val21d ago

Three inches of rain in one night here in Houston and my neighbor's gravel pad sank six inches, so I feel your pain. @irisowens is right about the clay, but the real trick is digging out the topsoil first and compacting the base in layers before adding gravel. You want at least four inches of crushed stone compacted with a hand tamper, not just loose gravel dumped in a hole.

irisowens21d ago

Wait till you find out gravel alone doesn't stop a shed from sinking in Texas clay... that stuff expands like a sponge when it gets wet. I've seen people learn this the hard way down here more times than I can count. At least you caught it before the whole thing twisted into a pretzel shape. Concrete pads are the way to go, though I bet you wish you'd just done that from the start. Guess that's what we call a "hands on education" around here...

logan_mitchell21d ago

Compacted base is the real secret @irisowens is alluding to. Seen too many folks skip that step and wonder why their shed is leaning like the Tower of Pisa after one good storm. That TX clay is no joke, it'll grab gravel and pull it down like quicksand. Prepping the soil right is more important than what you put on top of it. Concrete's great but only if you've got solid ground underneath to hold it.