Prefabricated Slabs for Rural Houses

There are both advantages and disadvantages to using prefabricated slabs for rural houses, and careful consideration is required before making a choice.

Disadvantages

1. Insufficient Structural Stability
   Prefabricated slabs are fixed by overlapping their ends on the walls. Even if a ring beam is poured, their overall integrity is still weaker than that of cast-in-place floor slabs. Cast-in-place floor slabs are poured simultaneously with the ring beam, forming a continuous load-bearing structure, while the joints between prefabricated slabs can easily become stress concentration points, leading to cracking, deformation, and even affecting the overall stability of the house over long-term use.

2. Poor Waterproof Performance
   The joints between prefabricated slabs are weak points for waterproofing. If proper sealing measures are not taken during construction (such as not filling with waterproof mortar or not laying waterproof membranes), rainwater can easily seep into the interior through the gaps, causing problems such as moldy walls and floor slab leakage. This issue is particularly prominent in humid southern regions.

3. Inadequate Sound Insulation
   Prefabricated slabs are usually 12-15 centimeters thick and are either hollow or filled with lightweight aggregates inside, resulting in weak sound insulation against airborne noise. Sounds generated by normal activities upstairs (such as walking or moving furniture) can easily be transmitted downstairs, affecting living comfort.

4. Short Service Life
   The designed service life of prefabricated slabs is generally 30 years, but in actual use, problems such as cracking and leakage may occur prematurely due to material aging, construction defects, or overloading (such as illegal additional construction). Some cases show that low-quality prefabricated slabs may require repair within 10 years.

5. Poor Earthquake Resistance
   Prefabricated slabs are flexibly connected to the walls and are prone to detachment or displacement during earthquakes, causing secondary disasters. In contrast, cast-in-place floor slabs form an integral structure with the walls and beams through reinforcement bars, providing significantly stronger earthquake resistance.

Advantages

1. Low Cost
   Prefabricated slabs are produced in a standardized manner in factories, with lower material and labor costs compared to cast-in-place floor slabs, making them suitable for rural self-built houses with limited budgets.

2. Fast Construction Speed
   Prefabricated slabs can be produced in advance and then hoisted and assembled on-site. The installation of one floor slab only takes about 3 days, greatly shortening the construction period and reducing the impact of weather on construction.

Usage Recommendations

• Thickness Selection: Use 12-centimeter-thick slabs for ordinary rooms and at least 15-centimeter-thick slabs for the second floor or load-bearing areas (such as balconies).
• Length Limitation: The common length is 3-4.2 meters (increasing by 30 centimeters per increment). Customization is required for lengths exceeding 4.2 meters, but the transportation risk is high, and the slabs are prone to breakage.
• Construction Specifications: The joints should be filled with high-strength cement mortar and have waterproof treatment on the surface. Reinforcing bars should be added at the connections between the walls and the prefabricated slabs.