What is the Appropriate Thickness of Steel Plate for Prefabricated Houses

The selection of the thickness of steel plates for prefabricated houses should be determined based on specific uses and scenarios. There is no unified standard, but the commonly used range is between 3mm and 25mm, which should be comprehensively judged in combination with structural requirements, usage scenarios, material properties, and regulatory requirements.

1. Thickness Selection of Steel Plates for Building Structures

In prefabricated houses, if steel plates are used for building structures (such as frames and supports of light-gauge steel structure houses), the commonly used thickness range is from 3mm to 25mm, with 6mm, 8mm, and 10mm being the most common.

• Light-gauge steel structure houses: Thinner steel plates (such as 6mm or 8mm) are usually chosen to meet basic load-bearing requirements while controlling costs and self-weight.
• Heavy concrete structures or large-span houses: Thicker steel plates (such as 10mm to 25mm) are required to ensure structural stability and resist greater loads (such as wind pressure and seismic forces).
• Material properties and budget: Increasing the thickness of steel plates enhances strength and durability but also increases material costs and construction difficulty. A balance between performance and economy needs to be struck.

2. Thickness Selection of Steel Formwork (for Concrete Pouring)

If steel plates are used as formwork for concrete pouring (such as for cast-in-place floors and bridge beams), the thickness should be determined based on the type of project and load requirements:

• Civil building cast-in-place structures: Ordinary floor and beam formwork often uses 2.75mm or 3mm thick cold-rolled steel plates; frame column formwork, which needs to withstand greater lateral pressure, commonly uses 3.5mm or 4mm thick steel plates.
• Bridge engineering: Prefabricated box girders and T-beams generally use 6mm or 8mm thick hot-rolled steel plates, while large-span heavy-load beams may use 10mm thick steel plates; bridge pier formwork often uses 5mm or 6mm thick steel plates.
• Tunnel lining: The core lining formwork panels usually use 6mm or 8mm thick hot-rolled steel plates, and deep-buried tunnels or high-stress surrounding rock sections may use 10mm thick steel plates to enhance deformation resistance.

3. Regulatory and Construction Requirements

Current regulations (such as the Technical Code for Composite Steel Formwork GB/T 50214-2013) have clear constraints on the selection of steel plate thickness. In actual construction, the specific thickness should be determined in combination with the following factors:

• Design drawing requirements: Select the thickness based on structural calculation results to ensure compliance with load-bearing capacity and deformation control standards.
• Construction loads: Consider the lateral pressure and vibration loads during concrete pouring to avoid formwork deformation or bursting.
• Number of turnovers: If the formwork needs to be used multiple times, the thickness should be appropriately increased to improve wear resistance and fatigue resistance, and the thickness should not be arbitrarily reduced.