When we consolidate, we use two 1.5” heads Ostec’s with a 1.8-oz motor “ motor size counts”. A 15’ whip requires more power than a 10’ whip.
The first vibrator follows the vertical re bar layout and the pump hose is never more than a few feet ahead of the vibrator. Preferably both and concrete placement and vibration will be within the same ICF cell. This reduces pressure and insures good concrete consolidation. The second vibrator will follow and catch the areas between rods. As mentioned in a previous post, proper overlap of area of influence should be followed.

The concrete lifts should be stopped a few inches above the horizontal rods, so no rough pockets or holes will be left and no need to fill and specifically vibrate in each hole. In other words each lift should be smooth and flat just above each horizontal re bar.

Windowsills, headers and doors will also need similar internal vibration.

For end walls we simply insert the vibrator head between the foam bucks and the last tie, turn on and off the vibrator motor, on the downward stroke and slowly come up with full power.

In heavy re bar congested areas, extra passes maybe required. And if still not sure we may plunge a pencil vibrator through the foam just to make sure.

Can't agree much more with your post on consolidation. It seems some choose not to vibrate which i fail to undestand. "Total Concrete Homes provide positive cash flow , DAY ONE" --- very nice! "Why Wood You". Regards.

Why would someone not vibrate?

Well at least for me, in my early ICF days (1991) most of us were told not to internally vibrate by the form manufactures. Now days ICF manufactures will tell you that you need to insure that the concrete has been consolidated properly, and leave it up to the installer to decide which approach to use.

Why would most contractors decide not to internally vibrate?

Their bids are too tight and they don’t allow for enough manpower.
Recently I bid a small basement and a good competitor and I were within a $100.00 dollars of each other. But still a 3ed bidder was $2,000.00 below us. This 3ed bidder is obviously, not it for the long haul and probably, showed up with inadequate manpower and may not stand behind his work.

In the old days I used a pencil vibrator on the typical home and I could never keep up with the concrete pumping. So we went with lager, higher powered vibrators requiring 2 workers. On larger walls we double up the vibration crews mostly for consistency and structural integrity of the engineered wall.
But it is still a lot of hard work.

There is probably yet a 3ed reason that contractors choose not to internally vibrate and that is they are unaware of the number structural failures in this business.

This is a Blog on a house built with AAC Block.

http://www.synergybuilding.com/2009/05/energy-efficient-home-aac-block/

Seems like a key sentence is:

"To produce a flowable concrete, it is recommended that a high-range water-reducing admixture or self-consolidating concrete mix design be used in lieu of water addition. "

Eldon and I have many parallels.  In the early days everyone feared an internal vibrator.  We heard "bank on the blocks with a hammer and 2x4", use a "sawzall without a blade on the tie", "rod the wall with a piece of re-bar". 

It seems to have become the norm with all concrete mixes to "flood them with water" to achieve flow-ability.  Concrete has a Portland to water ratio that is followed at the plant.  When the ready-mix hits the site the first thing most people do is add water.  Doesn't make any difference whether it's flat work or ICF walls.  Get it off the truck and finish the job in new record time, every time.  This philosophy fly's in the face of ready-mix specs.
Increasing water on site typically REDUCES STRENGTH of concrete.

Many ICF installers don't  inspect there own work.. Don't ask don't tell.  Many don't know where to look and voids are found by the electrician or plumber.  Some are found while hanging toe cabinets, doors, ect.  If found lots don't know how to repair if they find a void. 
 
The pca rd 134 report did not use water to increase flow-ability of the mix.  I agree that the report didn't go far enough.  But the implied conclusion was internally vibrate for best consolidation. 


In the last few years there have been several commercial projects that had big issues with consolidation of concrete in ICF forms.  Some have been pushed down at a great cost as well as a GREAT BIG black eye to the ICF industry and all of us as installers. 

We all should learn how to properly consolidate concrete with internal vibrators as more and more commercial projects coming on line.  With more commercial comes more specs for steel and even concrete specs.  Also they bring out more inspectors. 

There are groups of contractors and installers that do internally vibrate.  Find someone and let them instruct  you how to internally vibrate.. it does take a little more time and some more help on pour day.  The rewards are a good nights sleep after the pour.  Less worry and you will be tired.

I prefer or require internal vibration every time as stated in previous posts. You should select a block where internal vibration is considered a matter of standard procedure.

Regarding water added at the site. Always ask for your full batch tickets and that way you will know exactly how much water you may choose to add and still remain at or above the mix design strength e.g. 3500 psi. Typically it's been my experience that unless you specifically ask you will get a summary ticket that does not include the batch mix weight details. If you don't have the batch weights you're guessing.

After allowable water for a specific mix (regardless of who adds it, plant, driver, you etc) --- for EACH gallon per yard (or each 10 gallons per truck), you cause a strength REDUCTION of approximately 10% from mix design. That said, if you have a 5 slump order and you are not allowed to add water (per the batch ticket ) and the slump is a 2 you may need to reject the truck. A rare but sometimes necessary occurance.

I have only seen one block I was reluctant to vibrate.  We did use a "pencil vibrator gingerly in it.  The block is no longer made.  As Eldon stated the vibrator motor and head size both play a big part in the consolidation of the concrete in the ICF block.  Experiment and see what you can get away with.  We have used vibrators as large as 2.5" and 3"  but these are scary.  Yuo learn to listen to the vibrator and  for signs the form is about to fail.  IE tie pop, bulge ect.  You must be awake during the pour. 

I used a 1" pencil vibrator on my own DIY basement ICF pour. It worked great and only cost $45 to rent for the morning. I just had my 17 yr old son follow along a couple feet behind me and do a once down and up in every cell as I pumped in each ~4' lift. No problems and no blowouts even when I got carried away and got the lift a little deeper than 4' in places (like 5-6').

I went and visited a nearby ICF pour a couple weeks before and they had at least 2 sq ft of EMPTY ICF below every window because they didn't vibrate. That was enough to convince me. I can't imagine why anyone wouldn't use an internal vibrator. It's cheap and easy. Even if you need to hire an extra guy for it you don't need a skilled worker and a pour doesn't take long. Hire a laborer for 2-3 hours.

Do you mean to imply that they didn't pour concrete directly under the window sills?