Concrete Pour

The Full Picture

A pour is the unit of concrete work in the field. Crews set forms and reinforcing, the concrete arrives by truck and is placed by chute, pump or bucket, then consolidated, screeded and finished. The drawings and the specs divide the structure into pours through construction and control joints, and the contractor's sequence decides which sections go together on a given day.

Sequence and size matter because concrete begins to set as it is placed. If new concrete is placed against concrete that has already set, a cold joint can form with weak bond, which is why large pours depend on truck spacing, crew size, pump capacity and mix set time. Typical limits come from the spec and the weather, so no single time applies. Placement is also tied to safety rules: OSHA requires that formwork drawings be kept at the site and that shoring be inspected before, during and after concrete placement, and that forms and shores stay until the concrete is strong enough to support its loads.

In takeoff the pour is quantified as volume. Length x width x thickness gives cubic feet, divided by 27 for CY. Footings, walls, slabs, columns and beams are taken off separately because they have different forms and different finishing. Reinforcing, formwork, embeds, finishing, curing and any pumping are carried as their own items. Estimators usually add a modest allowance for overage and uneven grade; the percentage varies by element and should not be treated as a standard.

Pricing pitfalls come from what is left out of the unit price. Short-load charges, minimum loads, extra trucks for long pours, a pump versus a chute, winter or hot-weather protection, and overtime for a long finishing day can each be missed. Another common mistake is measuring the concrete from the structural plan but not from the architectural or civil sheets, which add slab depressions, housekeeping pads and thickened edges.