Multi-story concrete slab construction

A system and method of constructing multi-story buildings having poured-in-place concrete floors for the upper floors, wherein a set of lower posts is erected, the lower posts having horizontal upper plates on their upper ends each with a centrally disposed aperture. Decking is supported by horizontal beams and defines a form to receive the concrete. The upper plates are masked and concrete is poured and screeded using the upper plates as screed guides, such that the upper surface of the concrete is generally flush with the upper surface of the upper plates. After removal of the masking, a set of upper posts having lower plates with centrally disposed pins are mounted atop the lower posts with the pins inserted into the apertures. The lower plates and upper plates are then welded to joint the lower and upper posts. The cycle is repeated for additional floors.