Container House Roof Collapsed

The roof of a container house has collapsed, which may be caused by various factors such as material hazards, construction violations, excessive loads, and weather impacts. Details are as follows:

Material hazards are one of the important causes. To save costs, some container houses use flammable materials such as polystyrene and polyurethane foam for their core materials. These materials have poor fire resistance and safety, and can be ignited by electrical welding sparks or cigarette butts. Moreover, once flammable and combustible sandwich materials catch fire, they burn rapidly. At 80℃, they melt, deform, and drip. The drippings can trigger more severe combustion, spreading the fire wherever they land, and the combustion products are highly toxic. At the same time, after a fire breaks out, the flames spread extremely quickly, easily leading to a collapse accident in a short period. After the collapse, the container houses are wrapped in iron sheets, making it difficult for firefighting water cannons to shoot water inside, greatly increasing the difficulty of firefighting and rescue work.

Construction violations may also cause roof collapses. For example, during the construction process, if insulation building materials are illegally stacked on the roof, and affected by rainfall, the materials absorb water and gain weight, increasing the load on the roof, which may trigger a collapse. The roof collapse accident of the gymnasium at the No. 34 Middle School in Qiqihar is an example. The construction unit illegally stacked perlite on the roof of the gymnasium, and due to rainfall, the perlite absorbed water and gained weight, increasing the load on the roof and causing the collapse.

Excessive loads cannot be ignored either. Buildings such as gymnasiums are generally relatively "hollow", with few columns supporting the roof, and their own bearing capacity is not strong. Placing heavy objects on the roof can be very dangerous. If the roof undergoes multiple repairs that significantly increase the load or heavy objects are stacked on it, under the combined effects, the grid structure may become severely overloaded and deformed, easily leading to an instant roof collapse.

Weather impacts may also cause roof collapses. Container houses are modular temporary buildings with poorer waterproof performance compared to permanent buildings. Continuous heavy rainfall may cause continuous water seepage through the joints, damaging the roof and even causing it to collapse.