Thickness of Prefabricated Slabs in Multistory Buildings

The thickness of prefabricated slabs in multistory buildings is typically 8 - 12 centimeters or more, with the specific thickness varying depending on factors such as the type of floor slab, new national standard requirements, and whether there are pipelines running through it.

I. Classification by Floor Slab Type

• Solid Floor Slabs: Solid floor slabs have no internal holes and have a relatively simple structure. Their thickness is generally 8 centimeters. This type of floor slab was widely used in the construction of early multistory buildings and can meet basic load-bearing and space-separation needs. However, due to its relatively large self-weight, it has certain requirements for the load-bearing capacity of the overall building structure.
• Hollow Floor Slabs: Hollow floor slabs have a hole design in the middle. This structure not only ensures that the floor slab has a certain strength but also reduces the self-weight of the floor slab, which is beneficial for reducing the overall self-weight of the building and the pressure on the foundation. The thickness of hollow floor slabs is usually 12 centimeters. Compared with solid floor slabs, they are more economical in terms of material usage and also have certain advantages in sound insulation and heat insulation.

II. Considering New National Standard Requirements The new national standard in 2025 has set clear requirements for the thickness of floor slabs, stipulating that floor slabs should not be thinner than 10 centimeters. This is to ensure that the floor slabs have sufficient strength and durability to better withstand various loads during the use of the building and safeguard living safety. After the implementation of the new national standard, the selection of the thickness of prefabricated slabs in multistory buildings needs to comply with this standard. Even solid floor slabs originally designed to be 8 centimeters thick may need to be adjusted to meet the new requirements.

III. Adjustment Based on Whether There Are Pipelines In ordinary residential buildings, if water pipes, electrical wires, and other pipelines need to run through the floor slabs, the thickness of the floor slabs needs to be increased to more than 12 centimeters. This is because running pipelines requires cutting grooves in the floor slabs, which will weaken the structural strength of the floor slabs. Increasing the thickness of the floor slabs can to a certain extent compensate for the strength loss caused by the grooves and ensure the safety and stability of the floor slabs. At the same time, thicker floor slabs also provide more space for the layout of pipelines, facilitating construction and maintenance.