Chat with a concrete guy changed how I look at post anchors

Had a pour-in-place concrete guy tell me last week that I'm wasting time with rapid-set bags for gate posts. Said he's pulled up 8 year old gates where the posts were just sitting in cracked quickcrete. Told me to use gravel at the bottom and mix my own 3000 psi mix instead. I laughed it off at first but then I went back to a job from 2021 and noticed one of my gate frames was already wobbling. Has anyone else switched to mixing their own concrete for load bearing posts?

3 comments

3 Comments

dixon.james1mo ago

Double down on that gravel base too, it lets water drain instead of freezing and cracking your concrete.

margaretramirez1mo ago

Man I used to be one of those people who thought gravel was just extra work for no reason lol. I always thought a solid pour straight onto dirt was fine if you compacted it well enough. But after my last patio cracked all the way through the first winter, I started looking into it more and realized the drainage part is key. Water freezes and expands, and without gravel it has nowhere to go but up into your concrete. You totally changed my mind on this one, I'm never skipping the gravel base again.

brianm661mo ago

Man that concrete guy knows his stuff. I read this article from some university extension office a while back about frost heave and it stuck with me. They said water seeping under a slab or post anchor and freezing is basically the number one reason things fail in colder climates. What @dixon.james said about doubling down on the gravel base is spot on. I started doing a solid 6 inches of crushed stone under my mailbox posts last year, tamped it down wet, and then poured a 3500 psi mix over it. That mailbox has been through two freeze-thaw cycles now and its still rock solid.