Rebar and Anchor Bolts

[sansert]

So I want to make sure contractor does this right. He is pouring a step footer and then block wall on top of that. He has vertical rebar in the footer but he says that it will extend into the blocks but not above any of them. The anchor bolts will be installed into the blocks for me to mount my framed wall to.Is this correct? Spacing of rebar? Supposed to pour footers saturday

 

[Falcon67]

May depend on your location, but IIRC J bolts should be 12" or less from corners and no more than 6' apart with at least 2 holding any sole plate. J bolts are inserted in the pour as soon as it's down, before the concrete starts to set up.

 

[sansert]

May depend on your location, but IIRC J bolts should be 12" or less from corners and no more than 6' apart with at least 2 holding any sole plate. J bolts are inserted in the pour as soon as it's down, before the concrete starts to set up.

Thanks!. my understanding is that the footers will be poured with horizontal and vertical rebar. After a few days the blocks foundation wall will be started with anywhere from 2-4 courses. I have been told the vertical rebar will extend thru the footer up to top of block level. From there the J bolts will be placed into the blocks and filled.

 

[scottydosnntkno]

Sounds fine/normal. Remember, most foundation guys know what they’re doing if they’ve been around more than a couple years. They often have the most expensive and hardest to fix part of any build. So they want it done right just as much as you do.

 

[gtae07]

May depend on your location, but IIRC J bolts should be 12" or less from corners and no more than 6' apart with at least 2 holding any sole plate. J bolts are inserted in the pour as soon as it's down, before the concrete starts to set up.

Local codes may specify more than that. For example, we’re required to have them something like every 30” or so down here, for hurricane winds.

One really neat tool I found for placing them is a plastic bracket and cap deal. It mounts to your sill plates and holds the bolts in position, exactly where you want them, and you can take your time with them instead of running around madly wet-stabbing them...

 

[JoeMcGov]

Concrete blocks "cells" (the empty part of the block) are on 8" centers. So your rebar and your wall bottom plate J bolts will be centered on a multiple of 8". In residential work I've often seen rebar and J bolts spaced on 48" centers.

 

[3onthetree]

Sounds right, no reason to extend rebar thru the top course as you can't attach a nut to it for the sill. The better way is to fill solid each cell that has the vert rebar all the way up (not just the top course) and combine the Jbolt in that cell too. It sounds like they'll be doing exactly that as its only 16"-32" high.

If you have the option to support the exterior slab at the garage door, either the use of a haunch or transition the int/ext slabs on the top course of block is also beneficial.

 

[sansert]

Thanks guys for the input. Sounds like they know what they are doing.

 

[spudley]

Thanks guys for the input. Sounds like they know what they are doing.

I don't know what I'm doing so I placed vertical rebar every 2', filled every core on a 2' block wall and placed j bolts every 4'. So far my under construction build hasn't wandered away.

 

[Falcon67]

Remember, most foundation guys know what they’re doing if they’ve been around more than a couple years.

Yea...I had to remind them to place the bolts and it was almost too late. YCMV (your contractor may vary)

 

[Jeepster04]

Sounds fine/normal. Remember, most foundation guys know what they’re doing if they’ve been around more than a couple years. They often have the most expensive and hardest to fix part of any build. So they want it done right just as much as you do.

Key word there is 'most.' And I do believe that is stretching it a bit.

 

[jetnow1]

May depend on your location, but IIRC J bolts should be 12" or less from corners and no more than 6' apart with at least 2 holding any sole plate. J bolts are inserted in the pour as soon as it's down, before the concrete starts to set up.

Also less than 12" from any joints in the plates, and as stated above some codes require closer spacing, especially coastal or other high wind areas. Multiple stories also require closer spacing. Check if your building dept requires
cast in hold downs to fasten to the wall studs also.

 

[willymakeit]

Do you have a permit? If so what does your design documents say?

 

[Diesel Dan]

Little over kill but on my taller block wall (7courses?) I welded rebar to the j-bolt so it reached almost to the footer after core filling.

Seen a breezeway blow off a house from 100+mph straight winds and took the top row of cement blocks with it. Obviously not core filled.

 

[Hdonly0]

I brought rebar verticle out of the slab every 4' and used open block on top row. Then tied a run of rebar horizontal on top, poured block full and then 12" j-bolts every 2'. Maybe overkill, but I am not worried about anything moving.

 

[Kaizen]

I as well had limited construction experience when i started my garage. My concrete guy used Straps that wrap around the edges of the sill and are nailed in place. its approved in my area. I really liked that as i was building it solo and had a concern of trying to get the wall up and lined up and down on raised J bolts. This way i just folded the strap down and was able to get the wall up on the wall without fuss.
If you are framing it yourself decide how big the walls will be that you are raising. This dictates the anchors. Mine was 36 feet wide so i did about 3 12 foot wide panels. make sure you account for extra studs if you do it this way. In my case the straps did not end up close enough to the ends of a few panels so i had to drill and install some anchors. Inspector was ok with it.

 

[aabirdman]

I believe that Code is 12" from corners and intersections and 32" on center after that. I try to lay them out so they will not interfere with stud layout. It just makes for a clean job. You could always drop in a vertical bar at each bolt location.

 

[6768rogues]

When it is backfilled on both sides, it does not need rebar, dowels or a keyway to secure the wall to the footer. If it has a cellar and only the outside is backfilled, the wall needs to be attached to the footer.