Building a Bathroom on Prefabricated Slabs in Rural Houses

When building a bathroom on prefabricated slabs in rural houses, it is essential to focus on key aspects such as wall setup, waterproofing, and pipe installation. The specific operations are as follows:

I. Wall Setup: Lightweight Materials to Reduce Load

The load-bearing capacity of prefabricated slabs is limited, so lightweight walls are needed to distribute the pressure. It is recommended to choose lightweight materials with a thickness not exceeding 120 millimeters (such as aerated concrete blocks, light steel keel gypsum boards, etc.), avoiding the use of heavy materials like solid bricks. The walls need to be firmly connected to the prefabricated slabs, which can be achieved using rebar planting or chemical bolts to ensure structural stability. If the bathroom space is large, structural columns or ring beams can be added within the walls to further enhance overall rigidity.

II. Waterproofing: Multi-Layer Protection to Prevent Leakage

Waterproofing is the core aspect of bathroom construction and should follow the process of 'base treatment → waterproof layer application → closed water test'.

1. Base Treatment: The surface of the prefabricated slab should be flat and crack-free. If there are any irregularities, they should be repaired with permeable leveling grout to enhance the adhesion between the base and the waterproof layer.
2. Waterproof Layer Application: Polyurethane waterproof coating is preferred due to its good elongation and aging resistance, which can cover easily leaking areas such as pipe roots and wall-floor junctions. The application should be done in 2-3 coats, with each coat's thickness controlled between 0.5-1 millimeter, and the total thickness should not be less than 1.5 millimeters. Avoid using membrane or polymer waterproof layers, as membrane seams are prone to cracking, and polymer waterproof layers have poor water resistance and tend to fail when exposed to moisture for long periods.
3. Closed Water Test: After the waterproof layer is completely dry, a 72-hour closed water test should be conducted, with the water level covering at least 20 millimeters above the highest point on the floor. If any leakage is observed during this period, the location should be marked and repaired, and the test should be repeated until it passes.

III. Pipe Installation: Double Water Testing to Ensure Safety

Drainage and water supply pipes should be tested independently to avoid rework later.

1. Pipe Water Testing: Before installation, conduct a water flow test on the drainage pipes (such as PVC pipes) to check for leaks at the joints; the water supply pipes (such as PPR pipes) should undergo a pressure test (pressure of 0.8 MPa, held for 30 minutes), with a pressure drop not exceeding 0.05 MPa considered as passing.
2. Sealing Treatment: After the pipes are fixed, use cement mortar or waterproof mortar to seal the holes through the walls to prevent moisture from penetrating along the pipes.
3. Second Closed Water Test: After the waterproof layers on the bathroom floor and walls, as well as the pipes, are all completed, a second 24-hour closed water test should be conducted to confirm no leakage before proceeding with subsequent work such as tiling.

Summary: When building a bathroom on prefabricated slabs, the principles of 'light load, waterproofing, and water testing' should be followed. By using lightweight walls to distribute the load, applying multi-layer waterproofing treatments, and conducting strict water testing procedures, the structural safety and functionality of the bathroom can be effectively ensured.