I've heard some mixed things on this..  Pouring an ICF basement in WI in the winter -  what would be a minimum temp to be able to pour?

jerkylips,

Here in Virginia we have poured when it is below 32 degrees. You may need to cover the top of the wall, but if you can get it off the truck then you should be fine. Once finished we have seen the sides of the walls litterally sweat due to the heat coming off the finished wall.

renangle

15 degrees,with additive

we can still work with out add or heat at 35* but with add down to 15* hot water for icf will get it to start to cook just cover the top and good to go.

In Vermont we have two jobs going on right now. One person has to wait until the weather gets above I think 36 degrees, good luck, federal funded project. The other the guy will pour whenever the trucks are ready to deliver. We would ask the batch plant they are going to make the decision on whether the weather permits.

vermonticf;

federally funded specs ............. now youv'e entered the twilight zone!


we just worked on a Katrina fire station rebuild, FEMA funded, the impact glazing was 3 layers and an 1-5/8" thick! But don't worry about paying for it that will fall on our granchildren

are you referring to the 'high early strength' stuff?  I've heard bad things about that - tons of cracking because it sets up/cures too fast.  I'm going solely on what I've heard, I know nothing about concrete.

Pretty tricky timing doing this in Wi winter. The pros can do it but if this is DIY I'd wait till spring.

Reason being you need to catch the right gap in the weather to dig the hole, pour the footing, build and reinforce the icf wall, pour, build the first floor deck and backfill enough to protect the soil under the footing from freezing.

This pretty much has to be done bam bam bam in about two - three days (temporarily insulating the footing overnight) to keep the soil from freezing under the footing. Then you've still got to keep that from happening the rest of the winter by keeping the basement above 32.

Pros in northern climates that have experience at it can handle it but I'd never try it unless a long mild period was forecast.

referring to antifreeze stuff

not going to be a diy project.  the contractor does the ICFs and SIPs, and said that they have done many during the winter.  He said basically what you said--they do the whole thing in 2-3 days.  I think he said they usually dig the hole on day 1, pour footings & build the forms on day 2, pour at end of day 2, & backfill on day 3.  Does that sound right?

I'm assuming those are 2 different things, then? 

jerkylips,

To me that sounds a little agressive, especially if you are doing a full basement. I have yet to run into a subcontractor that would pour the footings and build the entire basement, brace it suitably, have it plumb and square, and pour it in one day. Then to backfill the next day could become problematic, especially depending on the amount of backfill, height, soil, etc. I understand wanting to get the footer covered with soil to insulate, but it would be pretty aggressive to me.

Also, when is waterproofing going to happen, after hours on day 2?

you may be right, I may have the days wrong.  I know he said that they have it done within 3 days, but that may not include the backfilling.  I'm assuming they know what they're doing, so I'm not too hung up on it...

Don't you know know what they say when you "assume" something?

If you have any height of backfill at all, I wouldn't backfill until the concrete has had sufficient cure time to at least achieve 50% of its rated strength.  And most if not all ICF manufacturers recommend that the flooring system be installed before you backfill against the walls; otherwise, you risk the wall toppling over with nothing to resist movement at the top of the wall.

And what about the perimeter footing drain system?  That (perforated pipe, clean gravel, geotextile cloth, or equivalent system) has to be installed before backfilling.  And the waterproofing over the ICF wall as previously mentioned.

And what about the strength of your freshly poured concrete footers?  At only ~1 day cured are they sufficiently strong enough to support the concrete ICF wall without distortion?  And cold wintertime temperatures slow the curing process even more.

Your contractor's proposed timeline seems overly aggressive even under ideal working conditions.

you're probably right, & like I said, I probably got the dates wrong somehow.  That whole conversation was about 3 minutes long - just to give me an idea of what/when/how they do things.  They have done a lot of ICF's, so my point was just that they know more than I do, & at this point I shouldn't second-guess.

With no intent on being flippant, the question is sorta like "How big is a rock?" There are a lot of variables, but it comes down to how important is it to you, and how much extra effort and money is worth it. They place concrete in permafrost. There are accellerators, antifreeze agents, heat generators, and external means of heating, and additional insulation. Good contractors know their limits of comfort. For DIYs, it's best to work during the warmer times.

Pouring concrete in below-freezing temps is quite do-able. Basics: 1)The higher the cement content, the lower the temps you can place at. 2) the larger the mass (wider walls), the lower the temps you can place at, 3) A min. temp of the mix of about 55F must be achieved to start the chemical reaction. Hot water helps a lot. DJB Quad-Lock T&TS

d'tech is right. Another thing; you only have to keep it from freezing long enough for it to reach about 500 psi. After that, it shouldn't have a detrimental affect. In cold weather, it *should* reach that within 1.5 to 2 days.

i did my own icf house, basement to truss 8" thick down and 4" up at the end of January 08, we got lucky that it was nice (30 and sunny) every time we poured but the same night and next couple day were always brutal below zero plus wind chills, but that is what is great about icf just cover the top to hold the heat in, we always covered with hay (farmers) i would go and check on it the next day and move a piece of hay and the concrete would be warm, so plenty of curing time, first time building a house and cant believe how easy icfs were, pour and leave or pour and done is what i think describes them best, jerkylips im in north central wi

We have poured on 10 degree, still days with warm concrete without a problem. But once got cold mud on a 15 degree day with wind, froze before we could screed the top of the wall.......Big problem $$$$$