Concrete slabs of ceilings are popular building material. The production uses high -strength wire with a diameter of 5 mm for reinforcement. The main material in the manufacture is heavy concrete. For concrete, the cement mixture has a constant composition, and concrete has a high density. And also taken into account the aggregate of concrete and its size. Typically, for concrete slabs, crushed stone is used, which provides high weight, low cost and good quality. Such plates are highly spent and withstand evenly distributed loads from 300 to 2400 kgf/m. For the convenience of operation in such products, longitudinal voids are made. In the main floor slabs — six voids that provide ventilation well, and also protect against moisture and freezing in winter. The main cable is laid in these concrete slabs, which diverges throughout the room.