The sound insulation performance of steel-structured container houses is constrained by multiple structural factors, with the core being the synergistic effect of material properties, structural design, and construction techniques. As a building form using steel as a framework and containers as modules, its sound insulation performance depends not only on the acoustic properties of the steel itself but also on the combination of components such as walls, floors, doors, and windows.
Steel, as the main load-bearing structure, has high density and rigidity, offering good blocking of high-frequency noise but limited attenuation of low-frequency noise. This is because low-frequency sound waves have longer wavelengths and easily transmit energy through structural vibrations. For example, when external traffic noise or equipment vibrations reach the building, the steel frame may act as a sound bridge due to resonance, directly transmitting noise into the room. Furthermore, the thermal conductivity and sound transmission properties of steel are related; without sound insulation measures, steel beams and columns may become "invisible channels" for sound propagation, weakening the overall sound insulation effect.
Wall construction is a key factor affecting sound insulation performance. Traditional container houses typically have walls made of thin steel plates with low surface density, making them ineffective at blocking sound waves. To improve sound insulation, sound-absorbing materials such as glass wool, rock wool, or sound-absorbing felt need to be added to the inside of the steel plates. These porous materials significantly reduce noise penetration by absorbing sound energy and dissipating vibration energy. Simultaneously, the walls should have a double-layer structure with an air layer or sound-absorbing material in between, utilizing the elasticity of air to buffer sound wave impact. If there are gaps or poor joints in the walls, sound waves can seep through, so sealant or elastic gaskets must be used to seal the joints.
Floor design significantly impacts sound insulation between floors. Ordinary container houses often have floors made of a composite structure of steel plates and wood panels. Insufficient thickness can easily cause resonance, making footsteps and falling objects from upstairs clearly audible. Improvement solutions include increasing floor thickness, laying high-density sound-absorbing mats, or using a "floating floor" structure. Floating floors, using flexible supports to separate the floor slab from the main structure, cut off sound bridges and effectively reduce the transmission of impact noise. Furthermore, the choice of floor surface material is crucial; wood flooring, due to its porous fibrous structure, has sound-absorbing properties and is more effective at sound insulation than ceramic tiles.
The door and window system is a weak point in sound insulation. Ordinary container houses often use thin steel plates or aluminum alloys for doors and windows, resulting in poor sealing and a lack of soundproof glass, allowing external noise to easily intrude through gaps. Improvements include using double-glazed windows, adding sealing strips, and using casement windows (rather than sliding windows) to reduce gaps. For houses with high sound insulation requirements, soundproof curtains or sound-absorbing panels can be added to the inside of doors and windows to further block noise.
The roof structure's role in isolating rain noise and airborne sound cannot be ignored. Container houses often have corrugated steel roofs, which generate high-frequency noise when raindrops hit them. Without sound-absorbing treatment, significant rain noise will form inside the house. Improvement solutions include laying sound-absorbing cotton on the inside of the roof, installing soundproof ceilings, or using composite roof structures (such as steel plates + sound-absorbing layers + waterproof layers). In addition, the joints between the roof and walls must be properly sealed to prevent sound waves from seeping in through gaps.
The impact of structural connection methods on sound insulation is often overlooked. Modules in steel container houses are often connected by bolts or welding. If gaps exist at the joints or vibration isolation is not implemented, sound waves will be directly transmitted through the metal components. For example, if the steel beams of adjacent containers are not isolated with elastic gaskets, vibrations will be transmitted along the beams, forming sound bridges. Therefore, flexible vibration isolation materials, such as rubber pads or spring supports, must be used at module joints to cut off the vibration propagation path.
The precision of the construction process directly determines the stability of the sound insulation effect. If the sound insulation material in the walls is not densely packed, the floor slab elastic supports are installed incorrectly, or the sealing strips for doors and windows are not applied, the sound insulation performance will decrease. Therefore, strict quality control is required during construction to ensure that each process meets the sound insulation design requirements. For example, when filling glass wool, it is necessary to ensure that the material is evenly distributed and without gaps; when installing doors and windows, it is necessary to repeatedly adjust the fit of the sealing strips to ensure that there is no light or air leakage.
