I'm looking to replace my mailbox post, as the old one was just a metal pole hammered into the ground. This time, I want to do it right, but I have zero experience with Quickrete. I've seen videos showing the use of a post hole digger and mixing concrete in a wheelbarrow, but I don't have a wheelbarrow. Can I mix the concrete in a bucket instead, or can I mix it directly in the hole? The post will go about two feet deep; what size bag should I buy? A 50lb bag seems like overkill, but I'm unsure about the dry volume versus what it'll be once set. Also, how do I keep the post level while it sets? Any advice would be greatly appreciated!
3 Answers
For a hole that's 24 inches deep and 6 inches wide for a 4x4 post, Quickrete has a calculator that says one bag should do the trick. To keep the post steady while the concrete sets, use some 2x4s to prop it up like an A-frame, and you can take those off once it’s set. And as for sonotubes, they can be helpful, but for a mailbox post, they might be overkill unless you really want extra stability.
Honestly, you'll be surprised at how much 50lbs of concrete actually covers. I initially thought the same, but you'll probably need at least 2 bags. You can mix it directly in the hole by pouring dry concrete and adding water, then use a shovel to mix it while someone holds the post to keep it upright. It's just a mailbox, so no need to stress too much about perfect precision!
You might want to check out those metal posts that you can just pound into the ground—they make the job way easier and are around the same price. I’ve had mine for five years and it's holding strong!
Is it really necessary to use sonotubes, or can I skip that step for a mailbox post?