Concrete Slab Placement (Pouring Slab)
Following completion of any foundation inspection requirements and receiving an approved form survey, the slab is ready for placement.
Any equipment required for concrete placement should be provided by the contractor(s). Advance coordination with the concrete supplier and the concrete finishing contractor ensures timely arrival and placement of concrete with minimal delays and confusion. When ordering concrete (two or three days in advance – recommended) specify:
- The quantity needed (remember – order less than calculated per slab)
- The concrete mix desired (no admixes)
- Time of delivery
- The number and spacing between trucks (typically 8 to 10 minutes between trucks)
concrete foundation placement
Schedule a representative from the slab engineering firm to be present at the time of concrete placement. It is up to you to determine if water should be added to the mix (not to exceed the amount needed to obtain a 4″ slump, or 15 gallons–whichever is achieved first). It is the sole responsibility of the concrete supplier to get the concrete to the slab. It should not be your responsibility for any tractor work or winch trucks required to get trucks unstuck. When doubts arise concerning the ability of getting trucks to a form, get a concrete representative to verify accessibility.
The concrete finishing contractor directs the flow of concrete from the chute. He is responsible for making sure no cables are displaced and no concrete should escape under the form. The sides of the form must be vibrated to prevent honeycombs. The concrete (once placed in the forms) is leveled first by shovels and come-alongs, then by bull floats, and finally using a 15 foot metal screed. Checking the slab surface for level is critical. It can be checked by screeds, string line, and eyeball. The concrete finisher must be reminded of his responsibility for backcharges if latex float is needed (in excess of 2 bags typically) to level slab areas receiving vinyl, tile, or wood floor coverings. Make sure float forms are not pulled before the concrete has had sufficient time to set up. The entire slab surface must be completely troweled to the required finish and the edges of garage beams, entries, and thresholds are to be sponge floated to give a consistent rough finish. Garage surfaces should finished the same as the living area.
