How to Assemble Prefabricated Houses

The assembly methods for prefabricated houses are divided into three main categories based on material and structural differences: concrete, modular, and wooden structures. The specific assembly methods are as follows:

I. Concrete Prefabricated Component Assembly

1. Wet Connection Method

   • Key Points: Reserve a 50-100mm cast-in-place zone at the joints of prefabricated slabs, arrange connecting reinforcement, and pour micro-expansion concrete with a strength grade of C30 or higher. Curing is required for 28 days to reach the design strength.
   • Critical Details: The bonding surface between new and old concrete must be roughened (roughness ≥ 3mm) and coated with an interface agent to enhance adhesion. Seismic reinforcement must be provided at the joints (e.g., three Φ8 continuous bars for a 2400mm long slab), with a load-bearing capacity not less than 80% of the component itself.

2. Dry Connection Method

   • Bolt Connection: High-strength bolts (M16-M24) are embedded at the edges of prefabricated slabs and mechanically fixed using steel connectors, with torque controlled between 120-150 N·m.
   • Welding Connection: Suitable for galvanized steel floor slabs, with a 20mm welding margin reserved at the slab edges. CO₂ gas shielded welding is used, with a weld height of not less than 6mm.

3. Hybrid Connection System
   Combines prestressed steel strand tensioning (controlled stress at 0.7fptk) with cast-in-place zones, balancing the speed of dry construction with the integrity of wet construction, suitable for scenarios with high structural performance requirements.

II. Modular Building Assembly

The building is disassembled into independent modules (e.g., ceilings, floors, plumbing, and electrical systems), manufactured in a factory, and then transported to the site for assembly. Modules are connected using welding robots or highly automated methods, reducing construction time by over 60%. For example, a public housing project in Shenzhen was assembled from 6028 concrete modules, reducing the completion and delivery time from 2.5-3 years to just 1 year.

III. Wooden Structure Prefabricated Component Assembly

Components are assembled in sequence from bottom to top and from inside to outside according to design drawings, using screws, nails, wooden dowels, and other connectors to ensure firmness.

• Key Points: Align components before fixing, ensuring tight and flat joints. Hidden gaps can be beautified with sealant or decorative strips.
• Quality Control: After assembly, a comprehensive inspection of structural stability and appearance quality is required to ensure no looseness or deformation.

Key Common Requirements:

• Waterproofing: Joints must meet Class II waterproofing standards, such as laying specialized sealing tape (with an overlap width of ≥ 50mm).
• Compliance with Standards: All assembly methods must meet industry standards to ensure joint load-bearing capacity, seismic performance, and durability are up to standard.