Quality Standards for Prefabricated Houses

The quality standards for prefabricated houses encompass national standards, export standards, prefabricated construction standards, and core regulatory frameworks, as detailed below:

I. Compliance with National and Industry Standards
According to the Product Quality Law of the People's Republic of China, prefabricated houses must meet national and industry standards that ensure human health, personal safety, and property security, covering structural safety, living comfort, and the integrity of equipment and facilities. For example, prefabricated components must undergo load tests to verify their load-bearing capacity, ensuring that the designed live load is not less than 200 kilograms per square meter, and the dead load includes the self-weight of the slab and the weight of the finishing layer.

II. Export Standards for Prefabricated Houses

1. Domestic Compulsory Standards: Export products must pass relevant domestic inspections and meet compulsory standard requirements.
2. International Trade Standards: If there are differences between the destination country's standards and domestic standards, priority should be given to meeting the destination country's compulsory requirements for safety, health, and environmental protection; when the destination country's standards are unclear, refer to foreign standards designated by the national commodity inspection department.
3. Contractually Agreed Standards: When standards are explicitly agreed upon in the contract, both parties must strictly adhere to them; in the absence of such agreement, the destination country's compulsory standards take precedence.

III. Prefabricated House Construction Standards

1. Precision Control of Prefabricated Components:
   • Geometric Dimensions: The length, width, and thickness deviations of wall panels and floor slabs should be ≤ ±3mm, with diagonal errors ≤ 5mm.
   • Position of Embedded Parts: The positioning deviations of sleeves and reinforcing bars should be ≤ ±2mm.
   • Surface Flatness: The deviation should be < 3mm/2m, detected using total stations and 3D scanners.
2. On-site Installation Quality Acceptance:
   • Verticality: The verticality deviation of components should be < H/1000 (where H is the height) and ≤ 10mm.
   • Grout Fullness: The fullness of grout in sleeves should be ≥ 95%, with a grouting pressure of 0.2-0.4MPa.
   • Levelness: The cumulative deviation in the levelness of each floor slab should be ≤ 10mm.
   • Concealed Works: Inspect the wear of embedded lifting rings and the rust treatment of exposed reinforcing bars.

IV. Core Regulatory Framework

1. Structural Safety: The span of ordinary prefabricated slabs should be 3-6 meters, with special calculations required for spans exceeding this range; the resting length should be ≥ 10cm to ensure effective connection at supports.
2. Seismic Performance: Energy-dissipating devices or redundant constraints should be installed at joint connections, with overall integrity calculations conducted.
3. Sound and Thermal Insulation: The sound insulation level of party walls should be ≥ 50 decibels, and the impact sound pressure level of floor slabs should be ≤ 65 decibels.
4. Service Life: The design life should be 50 years in ordinary climatic regions, shortened by 20-30% in coastal or freeze-thaw regions; the thickness of anti-corrosion coatings should be ≥ 30mm.
5. Fire Safety Regulations: The fire resistance limit of load-bearing walls should be 3 hours, steel structures require fire protection, and fire separation zones should be established in kitchens and bathrooms.