My neighbor's deck posts are sinking because he didn't dig below the frost line.

Ryan Campbell · 2026-03-19T03:00:07.643958+00:00

He built it last fall and now the whole thing is tilting. I helped him check with a post hole digger and sure enough, he only went down about 18 inches. Where we live, you need at least 36 inches to get below the freeze. It matters because the ground pushes the posts up every winter. Has anyone else had to fix this after the fact, or is it always a total rebuild?

bailey.jennifer4mo ago

I used to figure eighteen inches was fine for a deck, but watching my neighbor's tilting mess this spring totally changed my mind.

5

brian_taylor155mo ago

Only 18 inches? That's not a deck post, that's a tent stake, lol.

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seanc735mo ago

Haha, a tent stake, that's funny @brian_taylor15. But for a small ground level deck, 18 inches deep with concrete is actually pretty solid. I mean, code around here is 12 inches for posts, so it's not that wild.

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derek_hill5mo ago

Ever try using screw piles to jack it back up and pin it? We did that for my buddy's shed and it saved a full tear down.

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