The recommended thickness for a concrete slab depends on its intended use and load requirements:

• Standard residential slabs and driveways typically require a minimum thickness of 100mm (4 inches) , which is sufficient for passenger vehicles and typical residential loads

• For heavier loads , such as trucks, RVs, or commercial vehicles, the slab thickness should be increased to 150mm to 200mm (6 to 8 inches) to prevent cracking and settling

• Garage slabs and slabs supporting heavy machinery are often recommended to be at least 6 inches thick , with some advice suggesting up to 8 inches for added durability

• For second-floor concrete slabs , thickness varies by area use, with main living areas typically requiring about 12 cm (4.7 inches) , support areas 10-12 cm, and complementary areas 8-10 cm

• Concrete patios generally follow the 4-inch thickness standard, but soil quality and expected weight influence this recommendation

In summary, a typical concrete slab thickness is around 4 inches for light residential use, increasing to 6-8 inches for heavier loads or commercial applications. For specialized uses, such as second floors or heavy equipment, thickness and reinforcement should be adjusted accordingly