What is the Thickness of Prefabricated House Slabs?

The common thicknesses of prefabricated house slabs are 120mm and 150mm. Here is a detailed explanation:

1. Standard Thickness: 120mm
120mm is the standard thickness for prefabricated house slabs, suitable for the floor structures of most ordinary residential buildings. This thickness can meet regular load requirements, such as daily use scenarios like human activities and furniture placement. Its design is based on the principles of structural mechanics, ensuring structural safety while considering material economy and construction convenience. Prefabricated slabs with a thickness of 120mm are widely used in multi-story residential buildings, office buildings, and other structures, representing a standardized choice formed through long-term practice in the construction industry.

2. Thickness for Special Requirements: 150mm
When prefabricated slabs need to embed water pipes, electrical wires, and other pipelines, a thickness of 150mm becomes necessary. The reasons are as follows:

• Pipeline Space Requirements: The diameters of water and electrical pipelines typically range from 20-50mm. After adding insulation or protective layers, an additional 30-50mm of slab thickness space is required. A thickness of 150mm ensures that the thickness of the concrete protective layer meets regulatory requirements (generally not less than 15mm), avoiding safety hazards caused by exposed pipelines.
• Structural Strength Compensation: Pipeline trenching weakens the local cross-section of the prefabricated slab. A thickness of 150mm effectively compensates for the loss of structural strength caused by trenching by increasing the amount of concrete, maintaining the overall load-bearing capacity of the floor.
• Construction Feasibility: A thicker slab body provides more flexible path options for pipeline layout, reducing pipeline cross-conflicts caused by insufficient space and improving construction efficiency.

3. Basis for Thickness Selection
The determination of prefabricated slab thickness requires comprehensive consideration of the following factors:

• Building Function: Different uses, such as residential and commercial buildings, have varying load requirements for floors, directly affecting thickness selection.
• Pipeline Complexity: The more complex the design of the water and electrical systems, the greater the required slab thickness.
• Regulatory Standards: Compliance with national standards such as the "Code for Design of Concrete Structures" (GB50010) regarding the minimum thickness of floors and the thickness of protective layers is necessary.
• Economy: Under the premise of meeting safety and functionality, priority is given to selecting the standard thickness with lower costs.

In actual engineering projects, designers will perform structural calculations based on specific needs to ultimately determine the thickness of the prefabricated slabs. For example, in ordinary residential buildings without pipeline embedding, a thickness of 120mm can meet the requirements; while in kitchen and bathroom areas that require centralized layout of water and electrical pipelines, a thickness of 150mm is necessary to ensure quality.