My plans to build my house using arxx icf (for all floors) consisted of constructing the foundation this Summer, and continuing with the first and second floors next Spring. I'd planned on completing the foundation (full basement) and capping it and winterizing it so that I'd begin next Spring with that much less to accomplish for the completion of the house in 2011.

A friend that regularly builds with icf's tells me that this is a bad idea pointing out that the cold joint will be problematic and that the last course of forms may change enough over the next few seasons making the fit between it and the new courses potentially disastrous.

As a Stone Mason contractor I'm familiar with the weak bonding properties of concrete to concrete but I figured that by ending with a rough finished half course and plenty of dowels this wouldn't be be a problem. The fitting of this year's forms to next year's seems more challenging.

Am I opening a can of worms by proceeding this way, or are these factors that are fairly readily surmountable obstacles? 

I think your friend was reffering to "shrinkage" if I understand correctly. Once the blocks are poured shrinkage is not something I"d be conrcerned with and the cold joint will happen no matter what since you have to build one floor at a time. Hope this helps.
Cheers!

Delprete,

You might want to look at using a bonding agent to connect the two concrete placements.  Depending upon the width of the wall, it may be possible to include a keyway in the first placement to help lock the upper wall in place.

Honestly, I don't think you have anything to worry about.
The biggest problem would be to make sure that the top of the concrete and the tops of the forms stay clean and undamaged over the winter. Adding extra short dowels will help the cold joint, but it is not a big problem if you don't use them.

Thanks for the replies. I also spoke with an Arxx rep.and he reiterated the responses here.

Mark,

I like a week minimum which usually corresponds to about 70% of ordered mix design (e.g. 70% of 3000 psi, etc.) Every now and then all the planets are aligned and we have to wait a few days to make sure we aren't getting ahead of ourselves. However, this is usually not a problem because you have to take down braces and erect the next floor -- often you will need to wait for the framer to complete a floor. That said, a more important "wait" is to make sure the slab is ready for the first loading. On commerical work which is where I spend a lot of time, this problem is handled for you. Typcially, they (the general contractor) wants to load the wall (e.g. weld to the embeds in the ICF) as soon as possible. They will do a 3 day or 5 day etc. break test on the concrete to see if it is ready to load or not. The engineer will say go or no go. Regards.

Mark,

Not being from Maine, I need to ask you what do you mean when you say your Ranch style home will be sitting on a foundation.  Does this mean you will be sitting on basement walls.  If so, then if the walls are buried, I would suggest that you price 4000 PSI mix with a good slump instead of 3000 PSI.  The higher PSI will make the concrete less porous with everything else being equal.

Thanks for the replies.

I'm not from Maine yet and hope to be there soon. My definition of a ranch is a single story, retangular shaped house. In my plan I have 3 rooms side by side, long axis of house is 90' perpendicualr to due south. The house will sit on a full basement, not slab or crawl space.

Mark