new deck post to concrete connection


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Old 01-30-22, 12:25 PM
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new deck post to concrete connection

Thanks in advance for any feedback on this question.
I'm building a new deck. We'll be using 12" sonotubes and 5000psi concrete for footings. My question is on the post-to-concrete connection. Do I need to embed the brace in the wet concrete? Or can I go ahead and pour the concrete, and then fasten a post base to the footing by drilling the required holes in the concrete? I see both types of connections, but I'm wondering if one method is preferred over the other?
 
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Old 01-30-22, 12:32 PM
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Sinking the brace in wet concrete is easier.
 
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Old 01-30-22, 12:41 PM
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You can do either. The thing is, many diy'ers often don't think about getting their posts in "exactly" the right place. Or they mistakenly think that its going to be "close enough". Even some contractors don't take the time to get it right. Doing it later does have the advantage in that it allows for some margin of error. If you set them in concrete that's great, but you better be sure they are in the EXACT right location.

Drilling and epoxying bolts in later is the way to handle it, but you must brush and clean the hole by blowing compressed air into it, and repeating this multiple times until it is clean... or the epoxy won't bond well.

And measuring your footings carefully is the way to avoid any problems. Stringlines and batter boards can help with that, along with measuring the post layout for square, and accounting for the post backset from the overall deck perimeter.

You wouldn't believe how many decks I have seen with post bases that aren't centered on the column, and are offset to one side or the other. That's just due to poor planning.

I explained this once to a friend of mine who was building a deck, thinking he understood what I was telling him. When I visited again later, his footings were unbelievably off, and he wondered what to do now.
 
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Old 01-30-22, 03:11 PM
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XSleeper, thanks for the thoughtful response! One followup question... Any thoughts about embedding the post itself into the concrete?
 
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Old 01-30-22, 03:13 PM
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Yeah, don't do it - keep the post out of water with the brace and it will last a lot longer than being embedded in concrete and the additional moisture and water that brings with it.
 
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Old 02-06-22, 09:47 AM
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Embed a "J" bolt in the fresh concrete, make sure it does not stick up too far and interfere with the plate that the post sits on and use a string to line up your "J" bolts so they are straight in line with each other. https://images.app.goo.gl/dErz7mc72MDgTkcv7. 5000 psi concrete is way overkill, 2000 psi is sufficient.
 
 

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