17 inch.

Why a 1 3/4" air space behind the brick? 1" is sufficient.

My basement walkout side walls: 1/2" sheetrock + 2-1/2" ICF foam + 8" concrete + 2-1/2" ICF foam + 1-1/4" air gap + 2-3/4" king size brick = 17-1/2" finished thickness.

Is that a Nudura ICF wall?

the gap is due to the walls are not straight because of concrete slump, It was 3 or 2.
I am happy to use Nudura.

YOU POURED ICF WITH A 3 SLUMP?!?!?!?!?!?! Holy COW!!! I would be checking for voids EVERYWHERE to be safe.

I did many checks. The concrete was like water. We did not use vibrator. Forms would be blow out if we used vibrator. There is no any void and the concrete is strong because I did lots of cuts at that level. Nudura resisted to the presure. The walls are 10ft but I waited 2 hours for the last 4ft turn.
I allways state that you must order slump 6, check the slump before pouring. If it is low send it back. Otherwise you can have unpredicted results.

Posted By theInvincible on 24 Jul 2013 11:41 PM
I did many checks. The concrete was like water. We did not use vibrator. Forms would be blow out if we used vibrator. There is no any void and the concrete is strong because I did lots of cuts at that level. Nudura resisted to the presure. The walls are 10ft but I waited 2 hours for the last 4ft turn.
I allways state that you must order slump 6, check the slump before pouring. If it is low send it back. Otherwise you can have unpredicted results.

Was this a DIY job?
When you mention the wall is not straight, are you talking about the ICF wall being out of square? If so, how many inches is it off by?

Posted By Midsouth ICF on 24 Jul 2013 09:11 PM
YOU POURED ICF WITH A 3 SLUMP?!?!?!?!?!?! Holy COW!!! I would be checking for voids EVERYWHERE to be safe.

It was a 3 slump, and like water? I think you may have slump a little confused unless you added a ton of plasticizer to it.

Posted By BrianBaron on 25 Jul 2013 04:31 PM

Posted By Midsouth ICF on 24 Jul 2013 09:11 PM
YOU POURED ICF WITH A 3 SLUMP?!?!?!?!?!?! Holy COW!!! I would be checking for voids EVERYWHERE to be safe.

It was a 3 slump, and like water? I think you may have slump a little confused unless you added a ton of plasticizer to it.

I thought the same thing. A 3" inch slump would be more like peanut butter than water. Unless like mentioned above, plasticizers were used. Hopefully they didn't water down the 3" slump at the job site to a watery slump.

Y'all or useguys depending... Don't confuse slump with plasticizers-- slump is slump. If a 3 slump gets some help and it performs like a 7 its a 7. Regards

If a 3 slump gets some help and it performs like a 7 its a 7

Except in cured strength. If you don't add liquid, it performs like a 3.

This is a DIY project.

The concrete was like water. But I do not know why it was like that.
But I can assure that it is very strong now. It is very hard to cut it and there is o any void.

However It was very bad for forms. I had two blow out holes. All the concrete was comming out from those holes. We worked like crazy to stop concrete inside the forms.

We did not water the concrete at the site. It came like that.

Do not accept any concrete like water.
Send it back.
I was lucky I did not have big problems.

Plasticizer is acceptable in increasing slump without affecting strength, it can be added both at the batch plant and on site. a typical concrete mix is a 3" slump, plus or minus 1", not easy to place in an ICF wall with rebar. Adding plasticizer to increase slump to 6" +/- will give you about an hour of increased slump for placement then revert back to it's original slump for the mix design.

Our typical ICF mix on residential builds is 20mpa (I believe that thats roughly 3000psi), curing in the perfect environment (The ICF forms themselves) a cylinder test proves that 9/10 times it fails at 28 days, but at 56 days it tests at 50-95% better then design strength.

No matter how 'wet' concrete is, you must consolidate the concrete, there is no excuse for not doing so.

Posted By theInvincible on 25 Jul 2013 10:31 PM
This is a DIY project.

The concrete was like water. But I do not know why it was like that.
But I can assure that it is very strong now. It is very hard to cut it and there is o any void.

However It was very bad for forms. I had two blow out holes. All the concrete was comming out from those holes. We worked like crazy to stop concrete inside the forms.

We did not water the concrete at the site. It came like that.

Do not accept any concrete like water.
Send it back.
I was lucky I did not have big problems.

From your description, it sounds like Agilia self levelling concrete. And it shows why you should never use self levelling concrete mixes in ICF walls.

A slump cone is a very cheap thing to own. There is no reason not to check the slump before accepting the batch. I always make the analogy, if you ordered a $50 steak dinner and they over cooked your steak, would you send it back, or spend the next hour trying to chew on it? Most answer, that they would send it back...

How much does a load of concrete cost you, $900? $1100 or even more? If you would send a steak back over $50 why the heck would you accept a $1000 load of concrete that is not what you ordered? Especially if it comes with the risk of compromising your new home or customers project?

"Like water", and a 3 slump just doesn't add up. Unless whom ever was measuring it got it backwards and measured the height of the pile, not how much it dropped.

You may not have watered down the concrete, but the drivers are very good at getting water in there without you noticing, and could have done it in route.

What would be the motivation for the driver to add water to the mix, if not requested by the concrete crew?  I have seen drivers add water at jobsite because a crew member told him to do so.  I have not heard about a driver showing this initative on his own.

Posted By Alton on 26 Jul 2013 04:41 PM
What would be the motivation for the driver to add water to the mix, if not requested by the concrete crew?  I have seen drivers add water at jobsite because a crew member told him to do so.  I have not heard about a driver showing this initative on his own.

I think if they screwed up the mix the driver doesn't want to haul it to the job site only to have it rejected and then he has to drive back with a fully loaded mix that will be sent to the dump. So the easier thing for him to avoid the hassle and rejection is to "fix it" himself and water it down.

At smaller concrete plants doesn't the driver do the at plant mixing also?

Posted By BrianBaron on 26 Jul 2013 03:58 PM
A slump cone is a very cheap thing to own. There is no reason not to check the slump before accepting the batch. I always make the analogy, if you ordered a $50 steak dinner and they over cooked your steak, would you send it back, or spend the next hour trying to chew on it? Most answer, that they would send it back...

How much does a load of concrete cost you, $900? $1100 or even more? If you would send a steak back over $50 why the heck would you accept a $1000 load of concrete that is not what you ordered? Especially if it comes with the risk of compromising your new home or customers project?

"Like water", and a 3 slump just doesn't add up. Unless whom ever was measuring it got it backwards and measured the height of the pile, not how much it dropped.

You may not have watered down the concrete, but the drivers are very good at getting water in there without you noticing, and could have done it in route.

I agree 100%

What's sad or scary is that some ICF guys don't even check slump at the site. The truck pulls up and they just dump it into the walls.

Posted By Chris Johnson on 26 Jul 2013 07:54 AM
Plasticizer is acceptable in increasing slump without affecting strength, it can be added both at the batch plant and on site. a typical concrete mix is a 3" slump, plus or minus 1", not easy to place in an ICF wall with rebar. Adding plasticizer to increase slump to 6" +/- will give you about an hour of increased slump for placement then revert back to it's original slump for the mix design.

Our typical ICF mix on residential builds is 20mpa (I believe that thats roughly 3000psi), curing in the perfect environment (The ICF forms themselves) a cylinder test proves that 9/10 times it fails at 28 days, but at 56 days it tests at 50-95% better then design strength.

No matter how 'wet' concrete is, you must consolidate the concrete, there is no excuse for not doing so.

So what about some of these ICF guys who dump water into the mix at the job site to increase the flow? I've talked to one such guy and he said that if it isn't flowing right, he just dumps water into the mix at the job site.

ND96 who posted on this forum reported that on his ICF wall mix which was originally a 3,500psi mix on pour day, showed up at 7,200psi on the 28th day. Yet the 4,000psi mix on pour day for the floors came back 6,600psi after 28 days. Which is plenty strong but it goes to show that the ICF provides the perfect curing environment and even though the initial mix was less psi, it turned out to be a higher psi than the exposed concrete mix.

Consolidating is mandatory. Sadly some ICF guys still refuse to do it and simply bang on the wall with a trowel thinking that is adequate for consolidation.