Disadvantages of Cement-Reinforced Prefabricated Houses
The disadvantages of cement-reinforced prefabricated houses are mainly reflected in aspects such as quality, performance, renovation, environmental protection, and construction dependency, as detailed below:
1. High Quality Risks
The quality of prefabricated houses is significantly influenced by construction standards. If the foundation is improperly treated or construction occurs in low-temperature environments, foundation settlement or wall cracks may occur within 5 years, with some cases showing repair costs reaching 25% of the original construction cost after 5 years. Low temperatures reduce concrete strength, leading to decreased structural stability and increased long-term maintenance costs.
2. Inadequate Sound Insulation and Waterproofing
Due to modular design, prefabricated panels offer weaker sound insulation compared to traditional buildings, with joint leakage rates nearly double those of cast-in-place structures. Regular waterproofing treatments are necessary; otherwise, rainwater can easily infiltrate through gaps, affecting living comfort.
3. Limited Spatial Layout
Modular design results in fixed functional area dimensions, making personalized adjustments difficult. These houses are currently mostly used for buildings up to two stories high. The exterior facade is prone to color variations due to material batch differences, with color differences reaching 15%-20% after 5 years, requiring frequent maintenance to maintain aesthetics.
4. Poor Connection Stability and Thermal Insulation
Prefabricated components are assembled by splicing, making joints prone to cracking and posing safety risks for buildings over three stories high. Additionally, concrete has a high thermal conductivity coefficient, causing indoor temperatures to rise in summer due to heat absorption and drop rapidly in winter due to heat dissipation, necessitating additional insulation layers or air conditioning systems for temperature regulation.
5. Difficult Renovation
Once reinforced concrete structures are formed, renovations requiring steel bar cutting are not only costly but may also compromise overall structural stability. For example, adding doors/windows or adjusting wall positions requires professional assessment; otherwise, safety hazards may arise.
6. Poor Environmental Adaptability
In humid regions, concrete easily absorbs moisture, leading to wall efflorescence and steel bar corrosion, shortening the building's lifespan. Measures such as waterproof coatings or ventilation designs are needed to mitigate these issues, but they increase initial costs.
7. Prominent Ecological and Environmental Issues
Cement production accounts for 8% of global CO2 emissions, and prefabricated components generate large amounts of non-degradable construction waste upon demolition. Compared to wooden or steel structures, their full lifecycle carbon footprint is higher, inconsistent with green building trends.
8. Seismic Performance Dependent on Construction Quality
If steel bars are not securely tied or concrete is not densely poured, brittle failure may occur during earthquakes, leading to structural collapse. Strict construction process control is required, but actual quality varies due to workers' skill differences.
9. Ventilation Design Requires Manual Intervention
The airtight concrete structure has poor natural ventilation, promoting mold growth. Additional mechanical ventilation systems are necessary; otherwise, long-term residence may trigger respiratory diseases and increase energy consumption.
