What size anchor bolts do you install/specify for your foundations?
I like to use 16″ – 18″ so that they lock in the top two rows.
In rebuilding a tornado-damaged garage, I installed 16″ anchor bolts in concrete along with a piece of 1/2″ rebar going down to the footer.
Your thoughts?
Bryan
“Objects in mirror appear closer than they are.”
Klakamp Construction, Findlay, Ohio – just south of the Glass City
Replies
Our local codes require 7" of embedment. IMO, on a conventionally framed wall without seismic holddowns, 3x plates, or whatever, those bolts will pull right through the bottom plate before they pull out of the concrete.
OK, so 7" of embedment.
Does that require the concrete or whatever it's embedded in to go lower than the first row of block?
The reason I'm asking: The garage I am rebuilding had 1 row of 6" block on top of 5 rows of 8" block.
The concrete floor was resting on the 8" block. The anchor bolts were isolated in the top row of block only.
When the tornado hit the house, it pulled the top row of 6" block right off the rest of the foundation.
Would it have helped if the anchor bolts would have extended into the next row of block? My opinion - yes, it would have.
Now, how would 7" of embedment help in this situation?
Bryan
"Objects in mirror appear closer than they are."
Klakamp Construction, Findlay, Ohio - just south of the Glass City
Edited 7/11/2008 11:26 pm ET by BryanKlakamp
FWIW I never understood anchor bolts into a block and not having a connection to the footing other than the mortar bond between block courses. Most stuff I have work on is poured foundations not block and in that situation we always tie bar from the footing up to the top 4" of th epour and then lay a bar horizontal , '"J" bolts hook under the bar.
The few block foundations I have done we brought bar out of the footing and put a hook at the top of the bar , the "J" bolt then hooked under the hook in the bar or we used "Bond Beam" of "Lintel Block" as the top course and dropped bar into that then hooked the "J" bolts .
They can't get your Goat if you don't tell them where it is hidden.
I think it would be fine if that core was filled and had a chunk of rebar preferably down into the footing. I should mention that we don't use block around here anymore. It's all ICF or otherwise poured.
In condition like that, I would have rebar extending down to the footer through all the block in the same unit the anchor bolts is in.
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I use half inch ones.
;)
it depends on the job. in a thickened edge slab, 8-12"
Welcome to the
Taunton University of Knowledge FHB Campus at Breaktime.
where ...
Excellence is its own reward!
In Florida you will have 2 #5s around the footer continuous, tied to #5 vertical hooks in all filled cells (all openings and every 4-5' on a wall without openings) tied to down hooks from the tie beam or bond beam (2 courses U block, poured with concrete and 4 #5 continuous around that or a formed 16" solid concrete beam with 4 #5s). HETA-20 Straps come out of the tie/bond beam to wrap over every truss.