What defines a flat slab floor system in construction?

A flat slab floor system in construction is characterized by its flat, thick concrete slab that is directly supported by columns without the use of beams or girders. This design allows for optimal use of vertical space, providing a minimal ceiling-to-floor dimension. Because the slab is thinner compared to traditional systems that incorporate beams, it often results in a lower overall building height while still maintaining structural integrity.

This attribute is especially beneficial in commercial buildings where maximizing usable height is crucial for various spaces, blending functionality with aesthetics. The absence of beams allows for uninterrupted ceiling heights and can facilitate easier installation of mechanical systems, which further enhances the system's efficiency and versatility.

In this context, the other options do not accurately represent the distinct features of a flat slab system. While thick concrete slabs resting on short walls relate to other structural systems, they do not capture the essence of flat slabs. Beams and girders are typically not present in a true flat slab design, and while radiant heating may be incorporated into various flooring systems, it does not specifically define the structural characteristics of a flat slab.