Thickness Requirements for Prefabricated House Slabs

The common thicknesses of prefabricated house slabs are 120mm and 150mm. For large-scale civil construction projects, the thickness can reach 20 - 30 centimeters, while rural self-built houses commonly use 12 - 15 centimeters. The specific thickness needs to be determined based on factors such as purpose, span, load, and material structure.

Common Thickness Ranges

According to the standard GB/T 16727-2023 for prefabricated concrete slabs, there are differences in slab thickness for civil buildings: Specialized projects such as large commercial complexes and industrial plants typically have slab thicknesses concentrated in the 20 - 30 centimeter range. In the residential sector, 120mm and 150mm are the mainstream specifications. Rural self-built houses usually directly select 12-centimeter standard slabs, with special areas like kitchens and bathrooms requiring thickening to about 15 centimeters, and roof slabs are recommended to be 12 - 15 centimeters thick.

Thickness Selection for Different Purposes

• General Residential Buildings: There is no clear classification of slab thickness corresponding to live load levels, but common specifications of 120mm and 150mm can meet daily living needs.
• Brick Formwork Engineering: Thickness specifications include 90mm, 100mm, 120mm, 200mm, etc., and need to be comprehensively determined based on project scale, structural form, and load conditions. For example, small brick formworks may select 90mm or 100mm, while large projects or high-load scenarios require the use of 200mm.
• Rural Self-Built Houses: The standard floor prefabricated slab thickness is 12 centimeters. Kitchens and bathrooms, due to the need for waterproofing and load-bearing, are usually thickened to 15 centimeters. Roof slabs, due to the need to withstand wind and snow loads, are recommended to be 12 - 15 centimeters thick.

Factors Influencing Thickness Selection

• Span: The span is positively correlated with the thickness. For every 1-meter increase in span, the thickness needs to increase by 3 - 5 centimeters. For example, the maximum span of commonly used prefabricated slabs in residential buildings is 4.2 meters, and custom-made thickened slabs are required for spans exceeding this length.
• Load: The greater the load, the higher the thickness requirement. Taking a gym as an example, its floor needs to bear a load of 500kg/㎡, and the thickness is increased by 5 - 8 centimeters compared to an ordinary bedroom.
• Material and Structure: Prefabricated slabs using new-type ceramsite concrete have a 40% increase in strength at a standard thickness of 18 centimeters. A double-layer bidirectional steel bar mesh structure can reduce the thickness by 2 - 3 centimeters, but the cost increases by 25%.