I have plans for a 2000 sq ft basement and 2000 sq ft main floor icf home.  The cement/foundation contractor told me he would be doing it in three pours.  I thought it would require only two....one for basement and one for main floor.  He said he would need two pours for the main floor because of wind on the job.  I asked him why he couldn't pour the main floor on a day there is no wind.  His way would mean three cold joints vs. two cold joints on a two pour job.  Anybody want to chime in here with their thoughts.....thanks

How much wind are we talking about?
If the wind is strong enough to move the forms with bracing in place, I would not want to pour even half a wall.
If you are paying for a pumper, then you are looking at twice the rental expense, as well as two cold joints. If wind is a constant problem, then add extra bracing on the down wind sides of the walls to compensate.

Wind? I don't like working when it is windy and on a pour day the boom will sway, all the more reason to do it in as few pours as possible. We don't have a lot of wind in Minnesota, that being said, what you are saying, your contractor says, doesn't make sense.

Is this project the contractors first job? If it is not, maybe there is a good reason to do it in 3 pours. He may be preparing you for a "worst case" scenario, and when he does it in 2 pours, you will be happy. Sounds like the contractor is experienced, and doesn't like making promises that he isn't able to guarantee. Since he knows he can't control the wind, his experience dictates, that he should probably control your expectations. Sounds like a good contractor. At this point you only real concern should be: Will he share the wealth if he is able to recognize any job cost savings?

I would want to do the main floor in one pour if it were my job. Clearly he is capable of pouring a full wall if he is pouring the basement in one shot. The only thing that I can think of when it comes to wind would be assembling the forms. If it is windy it can be frustrating stacking blocks higher and higher. I would still want to do a single pour for the main floor walls if it was my home.

Thought you might find this interesting.  2 pours -- 15' and 25' respectively -- pnematic external vibration and 15' wand internal vibration with vibration holes as required.  4000 psi concrete.  Zero problems.   Just in case you utilize a differenct ICF -- NUDURA is 18" tall and 96" long.   Regards.

We pour ICF walls in high winds quite often. Our contractors usually use the Arxx hook, along with lots of zip ties, to hold them together in high wind areas, such as out at the coast or east of the mountains. Source out some 48" long zip ties and with the rebar and proper bracing, your contractor should not have an issue with winds, unless it is some type of storm or unusual event.

Two pours is fine, as long as the joints are vertical. Do NOT allow him to make a horizontal cold joint unless the wall has been designed for it.

Jerry,
What problems are associated with horizontal joints?

Can you give us an example of how to design for a horizontal joint? More vertical rebar dowels?

How can you pour to get vertical joints?
Dave

Farmboy, Jerry will likely add some data here but 40 diameters is typical overlap -- some engineers like 48 diameters.
Thus for a number #4 rebar the overlap into next pour minimum is 20 inches, #5 is 25 inches, #6 is thirty inches etc. Another thing to consider is that often it is "much safer" to spend additional dollars on rebar to keep its termination point well above installers so that they cannot accidentally fall on it or scrape against it, etc. Also, given engineer approval (especially for commerical) you can wet set overlap bars.

For example -- 24' wall --- if you have two twelve foot pours one on top of the other and utilizing#5 verticals on 16" OC. Your ICF would go to 12' and your vertical steel would go to say 11' 11" -- your first concrete pour would be to approximately 11' 6" -- during this process (the pour) it is virtually impossible for someone to fall on or come in contact with the rebar since it terminates just below the top of the wall. Now as the pump truck cleans up and clears out - you take your precut 50" #5 (40 diameters (25 iinches) into the first pour and 40 diameters (25 inches) into the second pour) and wet set them all the way around the top of the pour. ACI 318 allows for this non-contact splice or you can elect to tie them. Again, ask your engineer. This approach -- although it uses more steel makes it easy to "not spill a drop of concrete" because you don't have to work the hose in and around the steel.

The next day you can start forming up from there and add the additional 12 feet with your verticals again terminating about two inches below the final height of 24'. Be carefull to terminate your pour first pour at a very consistent height so that you can cut all of your verticals for the second pour one time only. REgards.

This example illustrates letting the steel run higher than typical to keep it away from the installer.  REgards.

Farmboy, TexasICF hit it pretty well. The problem with the horizontal joint is that itis usually mid-height; right where the highest moment (bending force) is. If the wall is governed by bending, the steel is carrying the load, so as long as the amount of steel across the joint is developed as Tex said, All is good. But if it is like many residential walls where it is actually designed as non-reinforced, the steel is there only to control cracking. The load is carried by uncracked concrete.
But with a joint across the middle, you've already got a crack, so it voids that design. Just make sure it's designed as a fully reinforced wall.
The old lap splice length using diameters is VERY old. Since diameters is a linear dimension, and the rebar area required is a square dimension, it really doesn't come out right. It's usually fine for small bars, but not for larger bars. ACI 318 has the formulae; and the CRSI manual has tables. Unfortunately the ACI design for lap length has become unreasonably, and unnecessarily, complex.
Tex: I've stuck my foot in it before, so I'll preceed this with the fact that I don't know everything in all of the codes. But where does the ACI state that wet-setting is OK. I've only known it to be forbidden. And with these rebar in the most critical area, it's not a good idea (IMHO).

Jerry - I don't have a copy here but i am believe its ACI 318-99, Section 12.14.2.3 --- allows some tolerance in having non-contact splices (deemed to have the same strength due to twice the steel) - bars must be spaced not farther apart than 1/5 of the splice length or not to exceed 6 inches. i will check but need to know cause that's what i teach in the installers class and if it's wrong i need to correct. BTW -- i do know that regardless of what ACI says in the end-game its what the engineer says that matters Regards.

P.S. $%#%^ we are certainly held to incredible standards - how can you have a cold joint between every couple of CMU and get away with it?

Right, the distance is fine, but the bars have to be secured in place at the time the concrete goes in. If an engineer is doing very many things contrary to any code without some good backup, he probably won't be an insured, licensed engineer for very long. Unless bars were to be stabbed in within minutes of final placement, and vibrated well, it's not going to bond well.  I've often seen someone pounding them in with a hammer an hour or 2 after placing.
Yep. CMU has their own codes, and IMHO, not sufficient. But I'm still waiting for someone to come and ask me my opinion at code publishing time... But to answer your question. They have to have the required reinforcing across the joint. Unreinforced (or underreinforced) walls are no longer allowed, and have pretty strict Special Inspection guidelines per IBC, which most people ignore.