We had to do a little cutting of blocks here and there.   As we stack the blocks higher and higher some of the debris can be seen at the bottom of the blocks.   I'm kicking around ideas of connecting a vacuum cleaner to a pvc pipe and sucking up the garbage down there.   Someone I work with said not to worry.   In the grand scheme of things that little bit of chunks and shards of styrofoam won't do anything. 

What effect, if any, can some styrofoam cut residue have on concrete at the bottom of ICF blocks?    Is it worth the hassle of trying to clean up?   Will it affect the way the concrete bonds to the foundation/slab?

As long as there are not huge pieces of foam sitting down there, I wouldn't worry about it. Small pieces of styrofoam sitting down there will not effect the strength of the structure. The wall is kept on top of the foundation by the rebar sticking out of the foundation. That is what ties the wall to the foundation.

What's more important is making sure that the concrete consolidation is met. You don't want to have voids.

All those little beads and shredded pieces tend to collect at an end or in corners where they can build up to a great enough level to cause a cold joint or a void in the wall section. At the very least, you might consider sucking it out of those pockets and not worrying too much about the how the rest gets around a little.

This is why you don't cut the block while it's over the wall

If you have lots it will move to the corners and as Hybrid said it could be enough to cause a void, look at vacuuming it out or cut holes on the corners and run a garden house in there and flush it out, patch the holes with scrap wood when done.

Don't be embarrassed by this, the first wall I ever poured has a sharpie marker as part of it's structure and I've heard stories of tape measures, hammers, etc being part of walls...I'd love to be the demo guy in a couple hundred years and see how they look coming out!!!

Also, off topic, Lego in Europe takes all their molds when there done and instead of discarding them in the dump they are on their property encased in concrete so no one can take them to produce their blocks

You can use a gas powered leaf blower and push the debris under a window blockout and then suck it out with a shop vac. I have a lot of crap from the oak trees around my house that ended up in the walls.

Another reason I do mono-pours

It's easy to say that the foam or leaf bebris  is no problem. As an ICF contractor I can't technicaly make that claim. I can guess biased on my experience, but I'm not an engineer.

We've had this with both foam bead and leaf's. One inspector required us to wash each and every foam bead from the bottom of the wall. There was no cutting on this wall, all panels were cut on a chop saw.

I have found that a 4”x4” holes work well and if pour  around a 6” slump a small amount of concrete will flow out, but only a couple shovels or so. Then just cut it flat with the icf surface.

Some inspectors require you remove foam for a positive connection between the concrete wall and floor anyway.

Some inspectors require you remove foam for a positive connection between the concrete wall and floor anyway

Foam debris or are you talking about at the base of the ICF wall so the floor slabs actually contact the concrete in the ICF wall?

Yea, just for direct contact between the floor and wall. We had 2 inspectosr that required that. No big deal.
Even with a 1.5 oztec in use, not alot of mud came out the hole.
But nearly all the foam bead freely flowed out.

The spring oak tree catkins were heavy this year at my place. This is the stuff I have been dealing with in my ICF walls (example pictures grabbed via google):

http://www.flickr.com/photos/joelgillespie/6831796016/

http://www.flickr.com/photos/christ...526805631/

> Foam debris or are you talking about at the base of the ICF wall

Debris as in trash.  Created by cutting blocks and interlocking teeth falling off.   I used IntegraSpec blocks which have tiny fragile teeth about 1/4" square. 

Yea, just for direct contact between the floor and wall. We had 2 inspectosr that required that.

Is that code required?
Doesn't that short circuit any slab insulation you might have?

No, it was not required by code. However the inspector seen it, in one of the books and he required it.  Just one of those things man.