Rural House Blueprint: Precast Slab

The use of precast slabs in rural houses was common in the past, but it has many hidden dangers and has now been phased out. It is not recommended for use in newly built houses.

Basic Information about Precast Slabs

Precast slabs are commonly used floor slabs in early 20th-century construction. They are concrete precast components produced and processed in precast yards and directly transported to construction sites for installation. In rural areas, they are generally used for the roof of the first floor, floor intervals, and as floor and roof panels, serving as load-bearing slabs. In buildings with regular structures and a low number of floors, they can ensure a certain degree of safety.

Hidden Dangers of Precast Slabs

• Safety: Precast slabs are composed of individual slab units with gaps at the edges. In the event of a minor earthquake, the house may collapse. Low-quality precast slabs have a short service life and may cause house collapses and casualties without warning. Moreover, they have no restraining force on the walls and cannot form a unified whole with the house, lacking stability. When a disaster occurs, the house is prone to collapse due to slight settlement or tilting.
• Sound Insulation: The sound insulation effect is poor. On the one hand, there is not enough precast slab material, and sound has strong penetrating power. On the other hand, due to structural sound transmission, precast slabs are generally about 10 centimeters thick with long circular holes in the middle, acting as natural sound transmitters. Noise from neighboring rooms may even be amplified through these holes.
• Waterproofing: Water leakage is inevitable. There are gaps between each unit, and rainwater can easily seep in during the rainy season, corroding the steel bars and posing a risk of collapse. If the gaps are not properly treated during construction, irregular large cracks will be left. Over time, the gaps will become larger, and the house will leak severely when it rains.

Current Situation and Recommendations

Nowadays, some rural self-built houses adopt a method of using precast slabs on the first floor and cast-in-place concrete on the second floor, which can avoid the disadvantages of precast slabs preventing the house from forming a unified whole and causing repeated water leakage in the future. Some experts recommend demolishing all precast slab houses within 5 years. Nowadays, precast slab methods have been phased out in house construction, replaced by frame structures and reinforced concrete structures, further improving safety and quality.