Gray-faced Container House

A gray-faced container house generally refers to a container-style building that uses gray iron sheet as the main material or has a gray exterior. It is characterized by its sturdiness, durability, low cost, and high mobility, but attention must be paid to fire safety and compliance.

I. Material and Structural Characteristics

Gray iron sheet container houses are constructed using cold-rolled steel plates or galvanized iron sheets as the base material, which are connected through welding or bolts to form standardized box structures. Their core advantages include:

1. Structural Stability: They employ high-strength steel frames, offering superior wind and earthquake resistance compared to traditional prefabricated temporary buildings, and can withstand a uniformly distributed load of over 0.5 kN/㎡.
2. Sealing Performance: Automated welding processes ensure tight seams in the box structures, achieving a waterproof rating of IPX4 or higher, making them suitable for rainy climates.
3. Modular Design: They support multi-layer stacking (usually not exceeding 3 layers) and horizontal splicing, allowing for flexible space expansion. The standard dimensions of a single box are 20 feet (6.06×2.44×2.59 meters) or 40 feet (12.19×2.44×2.59 meters).

II. Application Scenarios and Limitations

1. Typical Uses:
   • Temporary dormitories and offices on construction sites
   • Warehousing and logistics transfer stations
   • Commercial exhibition spaces (such as container markets)
   • Emergency rescue command centers
2. Compliance Requirements:
   • They must comply with the "Interim Provisions on the Review and Acceptance of Fire Protection Design for Construction Projects," using non-combustible materials such as rock wool boards (Class A fire resistance) as the sandwich layer.
   • Residential container houses must be approved by the planning department, with a general usage period of no more than 2 years for a single building (which can be extended to 5 years in some regions).

III. Key Points of Fire Safety

1. Material Risks:
   • Polystyrene (EPS) and polyurethane (PU) sandwich panels can drip molten material when burning, with a fire spread rate of up to 4 m/min.
   • Case: In 2020, a container fire in Langfang was caused by an electrical switch circuit fault igniting weeds, with a burned area of 20㎡, highlighting the requirement for electrical wiring to be protected by metal conduits.
2. Fire Prevention Measures:
   • Spacing requirements: Maintain a fire separation distance of ≥6 meters between boxes or install firewalls (with a fire resistance limit of ≥3 hours).
   • Fire protection facilities: Equip every 100㎡ with 2 4kg dry powder fire extinguishers and ensure evacuation corridors are ≥1.1 meters wide.
   • Electrical safety: Use explosion-proof lighting fixtures and install 30mA leakage protectors on socket circuits.

IV. Economic and Environmental Benefits

1. Cost Composition:
   • New container purchase price: Approximately 12,000-19,000 yuan for a 20-foot standard container and 23,000-40,000 yuan for a 40-foot container.
   • Rental cost: 6 yuan/day per container (reference price in Beijing), including basic transportation and installation services.
2. Environmental Advantages:
   • The steel recycling rate exceeds 90%, and the amount of construction waste generated after dismantling is reduced by 65% compared to traditional concrete structures.
   • The factory prefabrication model shortens on-site construction time by 70% and reduces energy consumption by 50%.