Prefabrication Methods for Light Steel Houses

The prefabrication methods for light steel houses combine industrial precision manufacturing with standardized design, with the core process divided into four stages: design deepening, factory manufacturing, quality control, and packaging and transportation.

I. Design and Deepening Stage

1. Structural Calculation and Disassembly: Professional software such as PKPM and TEKLA are used for mechanical simulations to determine parameters like wind and snow loads, constructing a load-bearing system. The house is disassembled into thousands of individual components (such as steel beams, columns, and connectors), each assigned a unique number and processing drawing to ensure precise alignment in subsequent production.
2. Pipeline Pre-design: In the 3D model, the routing of electrical circuits and water supply and drainage pipes is planned simultaneously, with standardized interface positions reserved. For example, pipeline channels are embedded in wall modules in advance to avoid on-site excavation that could damage the structure, improving construction efficiency and safety.

II. Factory Automated Manufacturing Stage

1. Raw Material Preparation and Inspection: High-strength steel coils with hot-dip galvanized or aluminized-zinc coatings (such as G550 and Q235) are selected, with a yield strength of ≥550MPa and a zinc coating weight of ≥150g/㎡. Chemical composition and mechanical properties are tested before entering the factory to ensure the materials meet anti-corrosion and load-bearing requirements.
2. Cold Bending Forming: Steel coils pass through a fully automated production line, where they are rolled into C-shaped, U-shaped, L-shaped, and other cross-sectional shapes by multiple sets of rollers, achieving a forming accuracy of ±1mm. The production line speed ranges from 20 to 40 meters per minute, meeting large-scale production demands.
3. Automatic Punching and Cutting: Based on the deepened design data, bolt connection holes and pipeline passage holes are precisely punched into the components, which are then cut by hydraulic shears to avoid errors and structural damage caused by secondary punching on-site.
4. Modular Production: Walls, floors, roof trusses, etc., are broken down into independent modules, each integrating a skeleton frame, insulation layer, waterproof layer, and pre-installed pipelines, with a weight controlled within 200kg for easy subsequent lifting and assembly.

III. Quality Control Process

1. Dimensional Accuracy Inspection: Laser rangefinders or vernier calipers are used to spot-check the length, cross-sectional dimensions, and hole position deviations of components to ensure compliance with the Technical Specification for Low-rise Cold-formed Thin-wall Steel House Construction (JGJ 227) standard.
2. Coating Thickness Inspection: A coating thickness gauge is used to verify the thickness of the galvanized layer on the steel to prevent corrosion due to insufficient coating, extending the house's service life.
3. Welding Quality Inspection (if required): Non-destructive testing (such as magnetic particle inspection) is performed on pre-welded joints to ensure the welds are free from cracks, pores, and other defects, guaranteeing structural safety.

IV. Packaging and Transportation Components that pass inspection are packaged by number, accompanied by detailed installation drawings and lists, and transported to the construction site. The prefabrication error in the factory is ≤2mm, and the on-site assembly error is ≤5mm, reducing material waste; the steel structure has a recycling rate of 92%, meeting the requirements of LEED green building certification, and is suitable for scenarios such as rural self-built houses and tourist resort villas.