How to Damp-Proof Prefabricated Slab Houses

Damp-proofing for prefabricated slab houses can be achieved through the elevated slab damp-proofing method. This approach involves constructing an elevated layer to block the upward movement of moisture and incorporating ventilation design to maintain air circulation, thereby achieving the goal of damp-proofing.

I. Construction Process

1. Foundation Construction: First, lay the ground beams, which serve as the foundational support structure for the house and must ensure stability. Above the ground beams, build brickwork and install ventilation pipes. These pipes are used to guide air circulation and provide the basic conditions for subsequent damp-proofing.
2. Prefabricated Slab Installation: Place the prefabricated slabs on the brickwork structure. In some projects, a steel mesh is placed on the slabs, followed by pouring approximately 6 centimeters of reinforced concrete to enhance the overall structural strength. Surrounding brickwork can further secure the position of the slabs and prevent displacement.
3. Joint Sealing: After adjusting the position of the slabs to avoid misalignment, use concrete to seal the gaps between the slabs. This ensures the airtightness of the elevated layer and prevents moisture from seeping in through the gaps.

II. Ventilation Opening Setup

1. Location and Quantity: Reserve ventilation openings at the diagonal positions of the elevated layer to ensure air convection and improve air exchange efficiency. The ventilation openings must be directly connected to the outdoors to ensure an unobstructed air circulation path.
2. Size Adjustment: Adjust the size of the ventilation openings according to actual needs. During humid seasons, the area of the ventilation openings can be expanded to accelerate air circulation and reduce the humidity of the elevated layer. During dry seasons, the area can be appropriately reduced to prevent excessively low indoor humidity.
3. Elevation Control: The elevated layer of the prefabricated slabs is generally 30 to 50 centimeters above the ground, or determined to be around 45 centimeters according to the design elevation of plus or minus zero. Before laying, ensure that each room has ventilation openings and that their elevations are consistent to avoid affecting ventilation efficiency due to height differences.

III. Effects and Advantages

1. Damp-Proofing and Pest Prevention: The elevated layer physically blocks the upward movement of moisture, while the ventilation openings accelerate air circulation, effectively reducing indoor humidity and preventing the breeding of insects and ants.
2. Durability: This method is highly durable, with a single construction allowing for long-term use and reducing later maintenance costs.
3. Construction Convenience: Compared to earth backfilling, constructing an elevated layer reduces labor and material consumption. Additionally, subsequent floor pouring elevation and leveling are more convenient, avoiding ground subsidence caused by uneven backfilling.
4. Cost-Effectiveness: Although the initial cost is slightly higher than that of earth backfilling, in the long run, its damp-proofing effect and construction convenience make it the optimal choice when the budget allows.