House: Prefabricated or Cast-in-Place

It is generally better to use cast-in-place slabs for houses, but the choice should be based on specific needs and conditions. There are differences between cast-in-place slabs and prefabricated slabs in many aspects, and the following is a comparative analysis from different perspectives:

1. Earthquake Resistance
Cast-in-place slabs are poured integrally with the house frame. During an earthquake, the house structure works together, showing strong integrity and being less likely to collapse, especially suitable for high-rise buildings. Prefabricated slabs are installed by splicing, and their earthquake resistance at the joints is relatively weak, making them prone to cracking during earthquakes, with a more significant difference in high-rise buildings.

2. Waterproofing
Cast-in-place slabs are solid and hole-free structures, providing more reliable waterproofing performance when used in wet areas such as bathrooms and kitchens. Prefabricated slabs have honeycomb-shaped holes inside, and over long-term use, moisture can easily penetrate, causing the joints or the interior of the slab to become damp and increasing the risk of water leakage.

3. Cost and Construction Period
Prefabricated slabs have a lower cost, saving about half of the expenses, and have a fast construction speed and convenient installation. Cast-in-place slabs require on-site formwork erection, pouring, and curing. Just for the cement to dry completely, it takes more than 28 days, with high labor and material costs and a long construction period.

4. Renovation Space
Cast-in-place slabs allow flexible hole-cutting or installation of chandeliers, stairs, etc., with little impact on structural safety during renovation. Prefabricated slabs have limited load-bearing capacity, and random hole-cutting may damage the slab structure, causing safety hazards, with limited renovation space.

5. Overall Performance and Durability
Cast-in-place slabs are integrated with the overall building structure, having strong load-bearing capacity and a longer service life. They also perform excellently in terms of span, waterproofing, heat insulation, and sound insulation. Prefabricated slabs have a smaller span, and over long-term use, they may sink, causing roof leakage, with relatively weak overall performance and durability.

6. Identification Methods

• By Age: Houses built more than 15 years ago are mostly prefabricated slabs, while those built within the last 15 years are mostly cast-in-place slabs.
• By Pipe Laying Areas: If there are columns or reserved holes, it is a prefabricated slab; otherwise, it is a cast-in-place slab.
• Inside the House: If the walls have no beams and there are no columns at the intersections of walls, it is a prefabricated slab; if there are beams above the walls and columns at the intersections of walls, it is a cast-in-place slab.
• Drilling Test: Use an impact drill to make three holes 5 centimeters apart on the floor slab. If holes are drilled into empty spaces, it is a prefabricated slab; if not, it is a cast-in-place slab.

Summary: If you pursue earthquake resistance, waterproofing, renovation space, and overall performance, cast-in-place slabs are a better choice. If you have a limited budget and need fast construction, prefabricated slabs can meet basic needs. It is recommended to make a comprehensive decision based on the house's purpose, local earthquake resistance requirements, and long-term plans.