Hi photogman:

As stated in the article, decision not to vibrate the concrete was made at the job site without the concurrence of the design professionals. The decision to tear down the structure in my opinion is premature and at the moment an emotional reaction.

Even if the voids have been discovered in the concrete at some spots, it needs to be determined how extensive are the voids -- has the load carrying capability of the walls been impaired to the extent that the walls will not be able to carry all the intended dead and live loads.

I hope the decisions will be made rationally after making detailed analysis regarding the strength of the walls as-built. And I hope the needed repairs will be made in a cost-effective manner and the project would be put back on track. It is too bad that even if the project can be saved, it will take herculean effort to complete the project by the desired completion date because of the legal wrangling and the liability issues.

Problems do occur but it takes a great project manager to cut through the chase, come to a sensible solution, have every one buy into that and move on. Delays, and long completion times with ICF construction are common, and even though these problems are not unique to ICF construction, it is too bad that people have begun to associate these problems with ICF construction.

I am currently associated with a residential project where in addition to the issue of voids, the walls being out of plumb is a major issue and the home-owner demanded that the house be torne down. The shell is complete, even some finishing work had begun. It is a shame that instead of looking at the situation realistically and solving the problems, some times the emotions can flare up and rational thinking takes the back seat. This case has gone to arbitration.

If you look a little harder into this google the add and you can see what is the real problem.

If you sell a form in your back yard to a non-trained and installer, you, the seller are wrong!

Come out with it own up to the problem, we are here to help the whole industry and you will grow with it.
If more jobs go this way the icf name and your name will get hurt.
Sale forms to certified installers that have been trained on what can go bad if you play with the standard methods on placing concrete.
Just sell block ,to any one and this is what will happen over and over again, how long will you stay in demand like this.
Price does not equal value. You get what you pay for.
What do I know I just pour concrete for a liveing?

Okay, I guess its time to post on this.

Having investigated and provided expert testimony on many failed ICF projects, completion of numerous reparative measures reports, provided chapter 17 special inspections, compiled research reports on ICF's and written install manuals for ICF manufactures, I think I can safely state the following.

Although the product "self consolidating concrete" works well in wood forms, of which have a release agent sprayed on them, as well as having a very limited about of obstructions for placement, such as the "ties" used to hold the forms together, ICF's have one major concrete placement disadvantage.

Consolidation

John Gadja's recent consolidation in ICF report, clearly states that external means of consolidation (pounding on a wall eg), or no consolidation does results in voids.  This is based on actual placement tests conducted by the PCA in ICF's.

Research conducted by myself on installed projects, for many different brands, and with many different installers proves one thing.  Proper consolidation techniques by internal vibratory means, is a must to ensure several concerns with consolidation.

Skip the voids, they are obvious and easy to find, go on to an issue I have termed "graveling".

This results due to several issues particular to ICF forms, and is primarily only found in ICF forms.  It primarily occurs at the bottom of a wall section that is being poured, and is usually the result of additives that attach to Portland molecules’.  And there are many additives that can cause this.  You know you are in trouble, and need to do something, if the forms become coated in a grey "Maalox" type coating.  This coating is a mixture of your Portland and fine aggregate, and due to the extensive exposed plastic area on the inside of the wall (remember this includes the tie area).  AS the concrete is placed, (most people simply dump it in), the falling coarse aggregate of the concrete mass impacts reinforcing steel and ties, effectively spraying the walls and components with the Portland and fine aggregates that "stick" to the forms and components, leaving the coarse aggregate to arrive at the bottom of the form prior to any real "filler" of Portland and fine aggregate.  This situation can be exacerbated by dry, windy conditions creating static attraction.

Basically, the result is that the lowest portions of the wall pour, usually the bottom 2-4 inches, is simply, very loosely bound coarse aggregate, with voids between the individual larger aggregate components.  In effect, your structural wall is now sitting on a pile of ball bearings, contained by the non structural ICF forms.

BTW this is a very, very common issue, so even though an investigator finds no open voids, they overlook the lowest portions of the pour, usually located at the floor or foundation line, and in the case of many wood floor systems in ICF's, behind the ledger and band boards used for floor support.

So although an ICF wall looks good and sounds solid when tapped or pounded, it very well may not be.  These situations are difficult to repair, structurally inadequate, allow water infiltration which exposes reinforcement to rapid deterioration or "rusting", and often results in post construction movement such as backfilling lateral movement at the footings, or simply spreading of the lowest portions of upper wall sections.

This, my friends, is the biggest reason to consolidate your walls, I have had to condemned and remove ICF structures for this issue, a few times now, and once the finishes are on, the repair bills are usually close to 75% of the construction costs, as you have to access both sides of the wall to repair, and that is IF it is repairable.  I know of several contractors, who are out of business because of this "gravelling" issue.  Don’t let it happen to you.

I can say that I have been working on ways to solve concrete placement issues in ICF's, and what I show below is what works best, and solves all issues, however requires additionally training to understand.

Although many people laugh and say we are crazy for pouring a standard mix, using only 5/8" crushed granite (no river rock, and in many cases we have to import our material), at 4.5" slump max, and using 1.5" plus diameter vibrators....consider this.  We completed a project, in which the poured wall strength was 3,000 PSI.  Core drilled and compression tests, 3 months later peaked over 9,000 PSI. 

There is a trick to placing concrete such as this, but the great thing about the placement technique, is that it is cleaner, easier and faster than you would think. 

Is it true....  Yes, on a large project, same day, identical walls, identical openings, I had an 11 man crew insisting that my way was incorrect and difficult.  So I ordered their 6-1/2 slump concrete with pea gravel and water reducers.  They took 5 hours to pour and consolidate 200' straight wall, 3 hours to clean up and align, with bulging issues, form failures and line/plumb issues....again with eleven men (five very qualified). 

That same pour I took my 5 man crew, my mix, placement and consolidation methods, and completed the other identical 200' wall sections including clean up and alignment, before they where done their 3 hours of cleaning up and straightening their walls.....Again with less men.

In short,  Installation of an ICF is difficult at best, it involves knowledge and skiils in trades such as carpentry, concrete forming, blockwork, reinforcing placement and concrete placement.  Dont be mislead by "simply stack and pour".  There is a lot more to it than you would expect.

For those that were a part of the “experience” on the site for the pour I spoke of above, please post your opinions, I would really like people to understand that there is a better way, even if it is a bit “off the wall”.

Mark Ross
www.powersmartbuilding.com  

It was a great experience, working on the project that Mark refers to in his post.  We poured about 2300 yds. of concrete in abt. 1.5 miles of walls and 65,000  sq. ft. of floors.  All of that in about 100 days.  We had the opportunity to strip walls and look at the results of the pours Mark referred to.  The things revealed were eye opening.  We used vibrators as large as 2.5" on 5" walls.  The gravelling that Mark refers to can occur between lifts in a wall also.  Because of the experience I have several size vibrators on the job.  We "punch vibrate" narrow columns and places that, due to web and steel placement, we recognize as problematic.  We "punch vibrate with the smallest vibrator available usually 7/8" or 1".  We stick it right through the foam into the concrete going up the pour to assure proper consolidation in tight places. 

It is my hope that all ICF professionals learn to use internal vibrators and the salesmen selling ICF,s refrain from telling people that internal vibration is optional.