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Through Bolt Sizes for Deck Footers

jar546

jar546

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Shouldn't there be more specifications for bolt sizes, embedment & length of bolts based on the wood size? the last two options are inadequate unless there are better specifications. I've seen this method on pole barns but the specs were prepared by an engineer. See Below:

Screen Shot 2023-12-06 at 08.58.03.png
 
How critical is the length of the bolt that sticks out of the post? The reason for the bolt is to lock the post to the concrete block. Is there a need for two bolts?
 
ICE said:
How critical is the length of the bolt that sticks out of the post? The reason for the bolt is to lock the post to the concrete block. Is there a need for two bolts?
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I've had #6 rebar specified at 18" in length in both directions so they would fit into a 24" round hold through a 6x6. This is what the engineers wanted
 
ICE said:
Is there a need for two bolts?
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Placing rebar in both directions in a concrete-set wood post helps it handle loads coming from any angle, not just straight up and down. It's like creating a strong mesh inside the concrete that grips the post better, making it tougher against wind or earthquakes. It's all about spreading out the stress so no single part gets overwhelmed, kind of like a team effort in holding the fort.
 
jar546 said:
Placing rebar in both directions in a concrete-set wood post helps it handle loads coming from any angle, not just straight up and down. It's like creating a strong mesh inside the concrete that grips the post better, making it tougher against wind or earthquakes. It's all about spreading out the stress so no single part gets overwhelmed, kind of like a team effort in holding the fort.
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Ya I don't think so. It's a 24" cube of concrete for a residential deck. Next I'll be hearing about Earth's rotation acting on a soon to be rotted post.
 
ICE said:
Ya I don't think so. It's a 24" cube of concrete for a residential deck. Next I'll be hearing about Earth's rotation acting on a soon to be rotted post.
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Dude, I looked at a pole barn that was not built right and whenever we had sustained winds over 10mph the doors would not open. It was lifting the building slightly on the upwind side and cracking the pavement along side the building.
 
jar546 said:
Dude, I looked at a pole barn that was not built right and whenever we had sustained winds over 10mph the doors would not open. It was lifting the building slightly on the upwind side and cracking the pavement along side the building.
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And you think that the thru-bolts on the bottom of the posts made a difference? I spent a year or so working for Morton Buildings. We had posts with a rebar stuck through it. We emptied a few bags of dry Sakrete and back-filled. Pulling against dirt is not the same as pulling against a block of concrete.

I witnessed a tornado pick up a long pole barn. It undulated as it flew across a corn field. Then the tornado caught it and turned it into shrapnel. I could see the rebar on the bottom of the post as the barn wasn't a month old and the little bit of Sakrete hadn't been moist enough to harden.

A 10 mph wind was it? I just knew Earth's rotation would muddy this up.
 
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Interesting post,

I have always been intrigued by the amount of effort that gets focused on the pinning of the post in the concrete and not the concrete to the earth.
  • (8) 3/8-Lags, x 4" tapped into a 6x6 at (2) a side in different locations has always been the rule of thumb we have used in the past when actually setting 6x6's in concrete starting way back in the 70's, has worked well other than the rotting of the post in the concrete.
Now look at what Simpson uses for connecting a 6x6 to their base which has a single bolt embed to the concrete sonotube footing?
  • My question is would not a couple of 90 angle clips with screws or nails if embedding in the concrete pour work just a well?
As noted by ICE, what is holding the smooth sonotube footing in the ground?
  • The concrete is inside the form is not?
  • If you dug a round hole and back filled, is the backfilled ground really tied into the other earth?
  • Whay aren't rebars required to be driven into the earth within the hole through the cardboard sonotube form providing pinning to the actual undisturbed Earth?
    • It would seem to question would it not make more sense to pin that also?
Just some things that I ask every time I look at a project for deck footing up here in the north..
 
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