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Question about my deck foundation - poured concrete footings in November and now they're cracking
Poured 6 footings for a 12x16 deck back in early November here in Ohio. Temps were around 40 degrees that day. Covered them with tarps like I read online. Checked them yesterday and there's hairline cracks running through 3 of them. Is this just from freeze-thaw or did I mess up the mix ratio?
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dianal941mo ago
Honestly, I used to think tarps would fix everything no matter what, but that point about pouring onto unfrozen ground changed my mind. If the ground underneath was still cold or had any frost in it, that alone could cause uneven settling and those hairline cracks. So yeah, the mix might be fine but the ground temp could be the real problem here.
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dylanmurray1d agoMost Upvoted
Used to think concrete was pretty forgiving if you just kept it covered and wet. Always figured air temp was the main thing to worry about during a pour. But reading through this thread really flipped my thinking on that. Ground temp being off can mess with the cure just as bad as a bad mix or not enough water. Never really gave much thought to frost still being in the ground under a tarp. Sounds like that would make the bottom set differently than the top, which would explain those thin cracks people see.
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