Placing Concrete in the ICF Foundation
All hands on deck and a cool, cloudy day make for a successful foundation pour.
I gathered a few friends to help out with the pour. Though it only takes a couple people to handle the concrete pump discharge others are needed to vibrate the forms, keep an eye out for blow-outs, screed off the top and place the anchor bolts.
We made 3 passes with the concrete pump around the forms, each time bringing the concrete up about 1/3 the way up. Doing this avoids applying too much pressure inside the forms at once. And if there is a blow-out we can make a repair easier without fighting several feet of concrete above the break.
I don’t like watering down the concrete so we poured it as stiff as possible so rodding and vibrating are important steps to consolidate the mix as each pass is made. I used a 1×3 to jam into the second and third passes to mix with the layer below.
At the same time another worker followed a few feet behind vibrating the ICFs with an ICF Wallbrator (AKA Arkie Wall Banger) – a large plastic device that chucks onto a drill. The internal gearing provides low-impact vibration.
The pour went quick – less than 2 hours and we were onto the basement slab. With the pump already paid for a half-day we took advantage and had the operator spread the concrete between screed pipes reducing the amount of dragging we had to do.
About 38 yards of concrete placed and floated with 5 workers in about 3 1/2 hours. No blowouts and no rain to ruin the slab finish so all-in-all a good day.