It's the windy season here on the high plains in Arizona. We started to build a small house with EZ Block ICFs in early December but between bad weather and me needing a hip replacement we are just now getting back to it. We had the basement walls up 3 blocks high (3 feet) and when we came back to it to continue we found there was close to 1/2" of dirt blown inside the walls at the bottom over the winter. Painstakingly vacuumed it out (NOT easy with the rebar in the way!) Then before we could put more block up, another wind storm hit, and the dirt is back! It will take at least two days to vacuum again... I'm filling every nook and cranny with foam to keep more out, but laying plastic sheeting or tarps over the top of the walls is a waste of time when the 60+ winds hit. Any suggestions or am I worrying about the dirt too much?

Where in Arizona are you building?

It is a good idea to clean out the bottom where the ICF meets the footings since you want a good concrete bond between the wall and footing. A little dirt won't hurt but if it's 1/2 inch thick then it's good idea to clean it out.

Cold joints are always the weakest spot with concrete so minimizing dirt and even EPS dust on the footing to wall area is a good idea.

That's what I was thinking, and the reason I posted here was in the tiny hope someone would say "nah, it happens ask the time" lol... It's really difficult to vacuum it out, and just about the time we're done another windy day or two will come along... We're out between Snowflake and St John's. North of the White Mountains. 5400' grasslands and cattle country, not much to stop the winds.

The wind blew it in, perhaps a leaf blower would blow it out.

If it were me what I would seriously consider doing is this. About every 20 or 30 feet or so, cut a hole in the foam against the footing. Clean the dirt out on one side and make a foam dam. Then get your garden hose or pressure washer and wash the dirt along the wall and out the hole. This will be faster than vacuuming, I think, and get the footing cleaner. When you're ready to pour remove the dams, plug the holes with can foam or a piece of block foam, reinforce with some scabbing, and smile.

As for keeping the dust out it's worth trying to do that. I would cut some strips of OSB and nail cleats on them that fit snug inside the block. Lay them on top of the blocks and place some weight on them to hold them down. I don't think the wind will blow them away unless it's really strong.

Can you lift the wall a half inch and blow it out from underneath? Strap a 2x4 to the wall and pry it up.

Tend to agree with dmaceld that washing out the sand may be more effective than a vacuum. Wind blown sand is usually pretty fine and should flow out from underneath the block/footing interface pretty easily. Or make some pathways for it to move out, as suggested.

Is it not possible to use some plastic sheeting, cut to cover the top and over the two sides enough to use 1x strapping attached to the webs to keep the dust out? Seems that would tie everything together, and if the block can withstand the wind this little cover could too.

Good ideas, but there's always a caveat... E-Z block is air entrained concrete screen grid block, each 4 foot long block weighs less than 36 pounds. It's not foam so there is zero chance of raising a wall. I'm glad I posted here, the idea of washing it out is very appealing. We just have to go buy a pressure washer, lol. We will cut the block at the bottom for openings and wash out now, then again right before the pour. I appreciate the help!

I would try washing it out the cracks at the bottom before cutting bottoms. It may just wash out....Good Luck...

+1 on Washing it out. That is what I did before our pour. In my case, Fox block teeth leave the bottom edge of the block 1/2" above the footing so no cutting was necessary. You might want more water volume than a garden hose can provide to push the debris along, especially when you get the block stack higher. I used 5 gallon buckets to pour larger volumes of water into the wall, about 1 bucket every 5-6' of wall.

Posted By azbuddy on 03 Apr 2016 01:31 PM
Good ideas, but there's always a caveat... E-Z block is air entrained concrete screen grid block, each 4 foot long block weighs less than 36 pounds. It's not foam so there is zero chance of raising a wall. I'm glad I posted here, the idea of washing it out is very appealing. We just have to go buy a pressure washer, lol. We will cut the block at the bottom for openings and wash out now, then again right before the pour. I appreciate the help!

Is EZ Block the honeycomb CMU (Concrete Masonry Unit) design?

CMU is basically air entrapped concrete.

What is the R-Value since it's heavy on concrete and thermal bridging? Is it R-15?

E-Z BLOCK IS R -18, but with the high mass walls acts like R- 47, "according to the company".

I can tell you I talked to the owner of an auto repair shop built 21 feet high with E-Z Block and he said in the winter in St George Utah they could leave it Friday afternoon and come back Monday morning and the temp would still be in the mid 50's with the heat off...
http://e-zblock.com/ It's foamed concrete with very fine fibers mixed in.