Out of total stupidity, doing a first ICF job, the dripdown concrete slop at the tops of walls was not cleaned when fresh.  Now we have a lot of drooled areas of cured 'crete, all on the outside of walls.

We want to finish these walls in a stucco look, but when we clean the cured 'crete drools, the 'crete is stuck to the EPS and pulls chunks out when pried off, and we end up with tearout areas that need fill to get things back to level.

What would you use to do the leveling, and then what would you use for the parged stucco-like finish?

Gene,

This is not a big deal. Simply use your spray foam to fill the void. Let the foam cure at least 24 hours then use a hack saw blade or something similar to carefully shave the excess foam off. Now you are ready to rasp the area. Voila you are ready for parging.

ICF Contractor

I have used the spray foam for filling voids under the soon to be stucco it all looked smooth at first but as the moisture from the stucco product absorbed into the foam it expanded what a mess, I would suggest using a thickened stucco material it can be thickened with silica sand to create a paste and then apply it just like filling screw dents in dry wall let it cure 24 hrs and start your scratch coat and then your finish coat.

The cement paste fill sounds good, Bill.  Thanks.

We are leaning toward doing the cover finish using diamond lath, then a two-coat real cement stucco over that.

Any experience with that?  If so, what is a good way of fastening the lath?  Are washers needed with the screws?

Gene,

If you are using a true stucco you do not need to fill the divits. The metal lathe will bridge them without a problem. One thing my stucco guy always preaches is that the ICF house is already weather tight so what ever you do to the outside is done only to protect the integrity of the stucco itself. That being said we either put a double layer of tar paper down first or a rain shield behind the stucco with weep holes. This allows any moisture behind the stucco to evacuate. Because your dew point will be behind the stucco and you will create moisture behind it from dew. Yes you will need to use screws and fender washers. We opt for stainless steel typically on a 16" grid. This may vary depending on the ICF you chose because the durability of the webs in ICFs vary greatly.

ICF Contractor

Gene I agree with icfcontractor if you are usin a true cement coat you do not need to pre fill the tearouts, Install the lath and appply the cement coat layers . The lathe can be attached with a product from Wind lock called lathe lock it is a galvanized washer with some small teeth on it to really hold things in place.

I have been using a spray on / trowel in acrylic product that I am happy with because it is not as labor intense as the true stucco trowel on's. The advice I gave above was for that type product.