How to Renovate the Toilet in a Prefabricated Slab House

Renovating the toilet in a prefabricated slab house requires meticulous planning, focusing on key aspects such as waterproofing, pipe installation, wall construction, and paying attention to safety and material selection.

1. Waterproofing

1. Slab Surface Treatment: Apply a permeable leveling compound on the surface of the prefabricated slab to ensure it is flat and permeable. This step fills minor cracks on the slab surface and enhances the adhesion of the waterproof layer.
2. Waterproof Layer Application: Choose polyurethane waterproof coating and apply it evenly 2-3 times to form a continuous waterproof membrane. Avoid using membrane or polymer waterproof layers as the numerous joints in prefabricated slabs make membranes prone to cracking due to substrate deformation.
3. Water Test: After the waterproof layer has cured, seal the floor drain and fill the floor to its highest point with water, maintaining it for 72 hours. Observe the ceiling or walls below for any leakage and proceed to the next step only after confirming no issues.

2. Pipe Installation and Water Testing

1. Drain Pipe Installation: Position the drain pipes according to the design, prioritizing the use of PVC-U pipes and sealing connections with special adhesive. If the toilet is far from the main sewage pipe, install a sewage lift pump to ensure smooth drainage.
2. Water Supply Pipe Installation: Use PPR pipes with hot-melt connections to prevent leaks. Maintain a 15cm distance between hot and cold water pipes to prevent loosening of connections due to thermal expansion and contraction.
3. Pipe Water Testing: After sealing all pipe connections, open the water source and check each section. Fill the drain pipes to the trap and observe for 10 minutes for any leakage; maintain a pressure of 0.6MPa in the water supply pipes for 30 minutes, with a pressure drop of ≤0.05MPa considered acceptable.

3. Wall Construction

1. Material Selection: Use aerated concrete blocks or light steel frame gypsum boards, with a wall thickness of ≤120mm, to reduce the load on the prefabricated slab.
2. Construction Points: Lay steel wire mesh (width ≥30cm) at the junction of new and old walls and smooth it with cement mortar to prevent cracks due to differential settlement.

4. Other Considerations

1. Safety Regulations: Turn off the main water and electricity switches before construction, wear insulating gloves when using electric tools, and set up scaffolding for high-altitude work.
2. Material Durability: Waterproof coatings must comply with the GB/T 19250 standard and have an E1-level environmental rating; pipes must pass national water-saving certification.
3. Environmental Control: Maintain humidity ≤85% and temperature ≥5℃ during construction. If it rains, cover the uncured waterproof layer with plastic film.