If you pour at the right slump, I always ask for a 5.5" slump, use a 4,000 psi mix, you you can save most of the vibrating for around openings. We use an external vibrator that goes on a drill, a round white plastic thing, I tell one guy to keep that running the whole time. And two cheap pencil vibrators, not cordless. One vibrator on top behind the guy with the hose, that one keeps the concrete off the top bar and bumps the verticals quickly, doesn't take much.
For openings wider than 5' fill under them with the hose, no vibration yet. For <5' and after filling under the wider ones, fill BOTH sides then vibrate in the lower corners of the openings, check by hitting the sides with a hammer to make sure they are full. Top off the wall with a guy on a vibrator just behind the hose guy, too close and the vibrating will cause the concrete to fill ahead of the hose, too far back the hose guy can't tell if the right amount is in the wall.

Posted By jeepster on 31 Jul 2011 07:24 AM
Thanks Arkie.

Did you use a 1" vibrator? With my 6" walls, I think it'll be tricky to even fish a 1" vibrator through the rebar. There's probably only a 1-1/2" gap between the staggering. Today or tomorrow I'm going to fabricate a rebar vibrator to use with an angle grinder. Since I have vert rebar every 18" or so, I'm thinking that will do the trick. I'll go ahead and rent the vibrator just in case.

We used external vibrators.  We had two Wallbrators from LiteForm going all of the time during the pour - one inside and one outside.

http://www.liteform.com/wallbrator/

The Wallbrator is like our white one, it does a nice mild job, but you need pencil vibrators for around openings.

Pencil vibrator is worthless. I have used a wallbanger on part of one job and it was worthless as well.

Jeepster this is a common problem because you need to use the two inside rebar fingers to install your rebar and not the middle, this allow enough room to use a 2" vibrator if necessary. Also many newbies fall into the trap of placing rebar every course hoizontally which is not necessary.

Posted By smartwall on 01 Aug 2011 08:18 AM
Also many newbies fall into the trap of placing rebar every course hoizontally which is not necessary.

That is a very dangerous blanket statement you have made, please be careful, many people take postings here as fact. There is some truth to the spacing, but each project and application are unique and need to be treated as such, along with local conditions, etc. etc.

Check the prescriptive method for spacing of rebar. The old rebar specs from most manufacturers was a horizontal every course and no mention of vertical rebar. As far as spacing for a basement, you want the rebar close to the inside wall because this is the side under tention.

You also need to determine backfill heights and soil types to make the call on rebar spacing...both horizontal and vertical, also seismic plays an important roll. This is why I asked to be careful, not everyone has the pleasure of sand or gravel backfill not exceeding 6' on a 8' wall in a very low earthquake area and no wind.

and on your basement wall the rebar is only to the inside provided the ICF wall goes from footing to u/s of floor, if it is a partial wall with a pony wall framed on top before you get to the floor your footing spec changes and your rebar goes to the outside since you are now dealing with an unsupported wall (Think retaining wall) that can 'piano hinge' on you.

Posted By smartwall on 01 Aug 2011 08:01 AM
Pencil vibrator is worthless. I have used a wallbanger on part of one job and it was worthless as well.

The Wallbrator and wallbanger appear to be similar on the outside, but I can't say if they perform the same since I've never touched a wallbanger.

The Wallbrators that we were using with 18V cordless drills on high speed seemed to do a good job of consolidating the concrete.  Under the windows, you could watch the concrete drop and bubbles come up along the sides while applying the wallbrator.  The same goes for over the windows and doors and at the top of the forms.  In the middle of the walls, you could see water/cream ooze a little between the forms when the wallbrator was applied.

In my case, all horizontal and vertical rebar was on 16" centers.  Horizontal rebar alternated every other row from near the inside face of the forms to near the middle of the forms.  The vertical rebar was dropped in between the rows of horizontal rebar.  Another thing I did was stack all of my horizontal rebar splices one on top of the other and tied them securely rather than laying the laps side by side.  I did this to reduce the chances of concrete building up on the horizontal laps.  I went around after each lift was completed and inspected from the top down and there was no measurable buildup of concrete on any of the horizontal rebar or ties.  I had a 10' piece of rebar handy if needed to drop down in the cavities and rattle around if needed to dislodge any concrete bridging, but it was never needed.

Most engineering calls for horizontal rebar 36" - 48" or so, we generally just go 32". The "pencil" vibrators are and inch or 1.5 and plenty powerful, too for some situations, but needed around openings. The wall vibrators are handy for all over. Our 12v cordless pencil vibrator, is nearly worthless.

Arkie, sounds like you did a very good job. Well thought out. Now back to my original point. The persciptive method recommends 2 rebar horizontal on 8' and 3 on 9' with no noted difference if it's a 6" core form or a 12" core form. But when you get to the verical rebar recommendations they get very speciific in regards ot the core size,height of the wall and backkfill height as well as the type of material used to backfill. Now if they are not very specific about the horizontal rebar can we deduce that they determined that the horizontal rebar didn't really help the tensile strength of the wall. But by being very specific about the vertical rebar this is the area to concentrate your resources. The reason for my post is I run into this alot. My competitors tell the customer that they only need to place rebar evey course horizontally. As far as the pencil, don't believe me go to the Oztec website. These are the specs on a 1" pencil. Area of influence 4", drop radius 6", this means on a 200 lin ft wall you would have to insert the head 400 times on each lift to properly consolidate the concrete . Also from their spec sheet the amount of concrete that can be properly consoliodated by a 1" pencil in the course of 1 hour is 2-4 yards. And as I asked the last time, is anyone pour icfs at this rate?

Also Arkie do you know what water reducer you used? As far as high range, mid range or low range and what was the slump before the water reducers were added?

What I know of vibrators I learned from experience. A solid wall takes little or no vibration, depending on the mix design, the wall vibrator is plenty. Around opening two of the cheap; (around $100) 1 3/8" head, 13,000 vibrations a minute, do the job.

I would like to try the Houston vibrator, but they are big and expensive.

Posted By smartwall on 02 Aug 2011 08:34 AM
Also Arkie do you know what water reducer you used? As far as high range, mid range or low range and what was the slump before the water reducers were added?

The batch plant indicated a mid range water reducer would be added at the plant to achieve 5.5"-6" slump.

Arkie , goog call on the mid range. A lot of people don't use it and it makes the pour so much easier. Brad whatever you use is up to you. My point is to provide info. to first timers. I poured my first icf in 1990 and the learning curve continues today, I'm a big fan of Helix, water reducers and when I pour a job I only use my monopour system. I can't buy more time so I try to work smarter.

Posted By arkie6 on 13 Mar 2011 05:21 AM
I built my own bracing from 2x4's and 4x8 sheets of 1/2" plywood. 

Hi Arkie, thank you for posting your pictures and the instructions. I built these braces and used them on my build, they worked great!

Sorry, I noticed that my question was already answered :-)