Container House 25

If a container house uses brand-new shipping container materials and is regularly maintained, it can typically be used for 25-30 years; if hot-dip galvanized main frame steel is used, its design life can reach 50 years.

I. Core Factors Affecting Service Life

1. Material Type

   • Steel Selection: The main frame steel of container houses is divided into hot-dip galvanized and cold-dip galvanized types. Hot-dip galvanized steel forms a physical barrier through the zinc coating, offering stronger corrosion resistance and a design life of up to 50 years; cold-dip galvanized steel has lower costs but weaker durability, typically lasting about 25 years.
   • Container Source: If modified from a brand-new shipping container, its original design life is 10-12 years (in a high-salt marine environment). However, after retirement, through inspection and maintenance (such as replacing corner fittings and repairing beams and columns), its lifespan can be extended to 25-30 years. For second-hand containers, it is necessary to confirm whether they are inspection-qualified boxes according to the GB/T12418 standard and whether all 8 corner fittings are intact and reliable.

2. Maintenance Frequency

   • Regularly inspect the rusting of corner fittings and beams and columns, and promptly replace aging components;
   • Apply anti-rust treatment to welded parts to prevent a decrease in structural strength due to cracks;
   • Clean the drainage system to prevent water accumulation from accelerating steel corrosion.

II. Lifespan Differences in Different Scenarios

1. Temporary Housing (such as construction site dormitories and field operation houses)
   • Usually, cold-dip galvanized steel or second-hand containers are used, with a design life of 10-15 years, mainly meeting short-term use needs and having a low maintenance frequency.
2. Permanent Residential/Commercial Buildings
   • Hot-dip galvanized steel or brand-new containers need to be used, and they must comply with the standard of a "design service life of 50 years (≥1.0)" in the Technical Regulations for Modular Combined Houses. The structure needs to pass restrictions such as seismic fortification (≤8 degrees), number of floors (≤6 floors), and height (≤24 m).

III. Key Measures to Extend Lifespan

1. Fire Protection Treatment: Use A-grade rock wool/glass wool to fill the enclosure structure, avoid flammable materials such as polystyrene, and reduce the risk of fire.
2. Anti-Corrosion Coating: Apply epoxy zinc-rich primer on the surface of steel to enhance weather resistance.
3. Structural Reinforcement: For special combined forms such as overhangs and misalignments, additional diagonal braces need to be added, and the opening of holes in the overhanging sections should be restricted to prevent local stress concentration.