Basic concept of foundation slab

The foundation slab is a reinforced or simple concrete slab that extends over the ground to evenly distribute the loads of a structure. Its main function is to serve as a stable base and support for buildings, avoiding differential settlements that could compromise the stability of the building. This base acts as a load transfer element from the structure to the foundation ground.

This construction technique is especially used on land with low bearing capacity or when a uniform distribution of the load is required to avoid specific stresses on the ground. The slab can act as a shallow foundation, and depending on its design and thickness, it can cover large areas under the structure or function as a complementary element in more complex foundation systems.

Materials used in the foundation slab

The foundation slab is generally constructed of concrete, which can be simple or reinforced with reinforcing steel. Concrete provides compressive strength and durability against ground conditions and structural loads. To improve its behavior, reinforcing steel is incorporated to withstand tensile and bending forces induced by loads and ground movements.

In addition to concrete and steel, it is common to use a layer of compacted granular base under the slab to improve the leveling and bearing capacity of the soil. Depending on the project, additives can be used to improve specific properties such as impermeability or resistance to chemical attack of the soil.

In some cases, waterproofing membranes or barriers against harmful gases (such as radon) are included over the slab to protect the structure and occupants, ensuring a healthy indoor environment and preventing the entry of moisture or subfloor gases.

Typical dimensions and thicknesses

The thickness of the foundation slab varies depending on the loads to be supported, the characteristics of the terrain and the type of structure. Generally, thicknesses range between 10 and 30 centimeters for residential buildings, while in industrial works or with greater loads it can exceed 50 centimeters.