I was searching for bases that will be used to anchor 4-ft x 4"x4" posts to concrete, and I saw this 12-gauge base for $18. I was also looking at these bases, but they seem a little flimsy.

I'm thinking that, in our case, it would be better to use heavy-duty brackets and anchor screws. Are there 4"x4" U-brackets?

How can I use brackets to reproduce these bases? The one I'd like to reproduce is this one because it's less visible. I was thinking of 4 2" "L" brackets, but I can't find them online. Something like this:

enter image description here

  • One of those bases is intended to hold a post upright, and one is merely intended to locate the post base and keep it off the concrete. What's your need? What's the problem with the 12-gauge one?
    – isherwood
    Apr 27 '18 at 14:59
  • I need to anchor the post to the concrete floor, and keep it straight and secure. I was looking for alternatives to the 12-gauge one because it's 30 posts and at $20 each, it's almost $600 worth of posts.
    – rbhat
    Apr 27 '18 at 15:48
  • 2
    That's why they're expensive--they're robust and purpose-built. No set of brackets will do what they do because they won't be joined at the corners. You're essentially replacing the strength of an in-ground base with something above ground. That's not easy. There's a reason you usually put 1/3 of a post below grade.
    – isherwood
    Apr 27 '18 at 16:02
  • isherwood is right. It isn't just that the expensive bracket is heavier gauge steel, a lot of its strength comes from its geometry. You can't duplicate that strength in keeping the post upright even using additional L brackets on the two open sides. You don't mention the application (e.g., fence posts vs. deck vs. carport). The right hardware can be expensive, but they couldn't stay in business making it if it wasn't justified for the application. That said, there may be a different, more cost-effective approach to what you want to accomplish. Can you add detail about your application?
    – fixer1234
    Apr 27 '18 at 18:45

If you’re looking to build your own base, you could copy one of these.

If it’s a retrofit installation, you could use Simpson RPBZ. And if it needs to stand off concrete, add CPS.

If you don’t like the looks of the metal side plates, you can use Simpson CPTZ.

For maximum resistance against rotation, you can use Simpson MPBZ.


I think you want a Simpson Strong-Tie Rebar Carport Saddle, 4 Inch x 4 Inch Model # RCPS3.5HDG

enter image description here

(6x6 pictured)

You'll need to borrow or rent a drill, as this is too big for your household hammer drill, and get a tube of cement glue. Drill the hole, fill with glue, and drop it in. The only trick is getting things level. The brackets are $6 Canadian at the orange store.

  • That won't hold up a post. Even in the direction perpendicular with the upright plates there'll be very little stability.
    – isherwood
    Apr 27 '18 at 17:37

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