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Construction · The Big DayICF Pour Day:
ICF Pour Day:
What Happens, and the Checklist Before the Pump Arrives
Pour day is when a stack of foam becomes a concrete house. It is also the day mistakes become permanent. Here is what happens, who does what, and the checklist we run before the pump truck rolls in.
The Short Answer
On pour day a concrete pump places the mix into the walls in lifts of about 2 to 4 feet, working around the building, while the crew vibrates the concrete, watches for bulges, keeps the walls plumb and straight with the bracing, and sets anchors in the top. Before the pump arrives, the steel must be inspected, every sleeve and buck braced, and the concrete mix and quantity confirmed. A typical house basement pours in one day.
The Checklist Before the Pour
- Steel inspected. Building inspector and, where required, the engineer have signed off.
- Bracing checked. Every brace tight, walls straight and plumb, corners and T-walls extra braced.
- Bucks braced. Window and door bucks cross-braced and vent holes in wide bottoms.
- Sleeves in. Every penetration on the list is in place. See wiring and plumbing in ICF.
- Anchors ready. J-bolts, straps and ledger connectors on hand, with a layout.
- Spare foam, screws and plywood on site for patching a bulge.
- Access. Room for the pump and trucks, overhead wires clear, neighbours warned.
- Weather. Cold-weather plan if needed. See pouring ICF in winter.
The Concrete
ICF mixes usually use smaller stone, often 3/8 inch, so the concrete flows around the webs and steel. Strength is set by the drawings, typically 20 to 30 MPa for residential walls. The slump is high enough to flow but not so wet that it blows the forms. The ready-mix plant should know it is an ICF pour; good suppliers have a standard ICF mix.
Order the quantity from the wall areas and core size, plus a margin. A 6-inch core takes about 1.4 cubic metres (m³) per 100 sq ft of wall; an 8-inch core about 1.9 m³. Running short with half a wall poured is not a fun phone call.
Get a Real Number for Your Project
Send us your plans or a rough sketch. We price the ICF work from real wall areas, not guesses, and tell you straight if ICF is not the right fit.
During the Pour
- Start at a corner away from openings, filling the bottom lift all the way around.
- Go around again for the next lift, giving the lower concrete time to stiffen.
- Fill under window bucks from both sides until concrete shows at the vent holes.
- Vibrate to remove voids, without over-vibrating near the forms.
- Watch and listen for bulges; fix them immediately with plywood and screws.
- Check plumb and straightness as the wall fills, adjusting the bracing.
- Strike off the top and set anchors at the marked locations.
After the Pour
Clean concrete off the forms and bracing before it sets. Cover the top in cold or hot weather. Leave the bracing on until the concrete has gained strength, usually a day or more, and do not backfill until the floor is on or the wall is braced, as the drawings require.
What Owners Should Do
Come and watch. It is a good day. Bring coffee for the crew; it is cheaper than a change order and twice as effective. Take photos of the steel before it disappears, and stay out of the way of the boom.
Get a Real Number for Your Project
Send us your plans or a rough sketch. We price the ICF work from real wall areas, not guesses, and tell you straight if ICF is not the right fit.
Questions We Get
How long does an ICF pour take?+
A typical house basement is poured in one day. Large or multi-storey jobs may pour in stages over several days.
What concrete mix is used for ICF?+
Usually a mix with small stone, often 3/8 inch, at the strength called for on the drawings, typically 20 to 30 MPa for houses. The supplier should know it is for ICF.
How much concrete does an ICF wall take?+
About 1.4 cubic metres per 100 sq ft of wall for a 6-inch core and about 1.9 for an 8-inch core.
What happens if an ICF wall bulges during the pour?+
The crew stops filling that spot, screws plywood over the bulge and pushes it back before the concrete sets. An experienced crew catches bulges early.
When can you backfill an ICF foundation?+
After the concrete has gained strength and the wall is supported by the floor system or bracing as the drawings require. Backfilling too early can crack or move the wall.