Disadvantages of Prefabricated Concrete Houses
The disadvantages of prefabricated concrete houses are mainly reflected in structural stability, sound and thermal insulation, durability, transportation and installation, design flexibility, environmental protection, and quality risks, as detailed below:
1. Insufficient Structural Stability and Seismic Performance
Prefabricated concrete houses are assembled using modular components, and the overall structural strength highly depends on the treatment of connection nodes. If construction does not strictly follow specifications for reinforcement (e.g., insufficient steel reinforcement ratios or welding defects), their seismic performance is significantly lower than that of cast-in-place concrete buildings. In seismic zones with intensities above 8 degrees, the risk of crack propagation is higher, potentially threatening building safety.
2. Poor Sound and Thermal Insulation
The sound insulation of prefabricated houses typically reaches only 30-40 decibels, far below the standard for ordinary residential buildings (≥50 decibels). This is mainly due to the high thermal conductivity of concrete (approximately 1.5 W/(m·K)), insufficient thickness of prefabricated panels, and the presence of long circular holes in the middle, which further reduce sound insulation capacity. Additionally, without added insulation layers, indoor heat loss in winter can be 1.3 times that of cast-in-place buildings, and gaps between panel joints can easily lead to water leakage.
3. Low Durability and High Maintenance Costs
When exposed to humid environments for extended periods, joints are prone to water seepage, causing steel reinforcement corrosion. Without anti-corrosion treatment, maintenance costs after 10 years of use may account for 20%-30% of the initial construction cost, far exceeding the 5%-10% for brick-and-mortar structures. Some cases show that repair costs after 5 years can even reach a quarter of the original construction cost.
4. Significant Limitations in Transportation and Installation
Each unit weighs 19-31 tons, requiring specialized flatbed trucks for transportation. In remote areas, logistics costs may exceed 15% of material costs, with transportation fees accounting for up to 5% of the total cost. On-site lifting requires at least a 50-ton crane, making implementation difficult in mountainous areas or other confined spaces, thus limiting their application scope.
5. Limited Design Flexibility
Most prefabricated houses are standard modules, with custom production cycles lasting 5-14 days. Later modifications, such as adding windows or rerouting pipelines, require cutting into the main structure, potentially damaging the embedded steel reinforcement network. Currently, they can only be used to construct buildings up to two stories high, and their facades are prone to color discrepancies, with the proportion of color differences possibly reaching 15%-20% after 5 years.
6. Prominent Environmental Issues
The recycling rate of mold waste (e.g., steel scrap) generated during prefabrication is only 60%-70%. Some small factories use non-environmentally friendly release agents, which may contaminate the soil and cause long-term impacts on the ecological environment.
7. High Quality Risks
When construction is not carried out according to specifications, there is a 7% probability of foundation settlement or wall cracks within 5 years. Construction in low-temperature environments is more prone to material shrinkage issues, affecting the building's service life.
