Young Black Haired Girl Naked On The Floor

Subfloor construction
The subfloor provides the strength of a floor. Many floors have no separate floor covering on top. The subfloor may also provide services like underfloor heating or ducts for air conditioning.
A ground-level floor can be an earthen floor made of soil, or be solid ground floors made of concrete slab. Floors above may be built on beams or joists or use structures like hollow core slabs.