Bathroom in Prefabricated Slab Houses

The design and construction of bathrooms in prefabricated slab houses should focus on waterproofing and structural safety, with specific attention to the following key points:

1. Thorough waterproofing is essential, especially addressing the issue of water leakage through slab joints
The joints between prefabricated floor slabs are natural channels for water leakage. If waterproofing is inadequate, water can seep through these joints to the floor below or into the walls. Taking old residential areas in Chengdu as an example, bathroom waterproofing requires double treatment on both walls and floors: the floor waterproofing layer should extend at least 30 centimeters up the walls, and the wall waterproofing layer should be at least 1.8 meters high, forming a continuous and closed waterproof barrier. During construction, it is necessary to first clean the slab joints and the base layer to ensure they are free of dust and oil, then apply waterproof coating, focusing on weak areas such as slab joints, wall corners, and pipe roots to avoid omissions.

2. When adding a new toilet, reduce structural load by prioritizing lightweight materials
If adding a bathroom on a prefabricated slab, the weight of wall materials must be strictly controlled. It is recommended to use lightweight partition walls (such as aerated concrete blocks, light steel keel gypsum boards, etc.), with a wall thickness not exceeding 120 millimeters to reduce the concentrated load on the prefabricated slab. Avoid using heavy materials like solid bricks and concrete to prevent slab cracking or deformation due to excessive load. Before construction, assess the load-bearing capacity of the prefabricated slab and perform structural reinforcement if necessary.

3. Waterproof layer construction should be layered, avoiding materials prone to cracking
The waterproof layer construction should follow the process of "penetration leveling → polyurethane waterproof layer → waterproof coating":

• Penetration leveling compound: First apply a penetrating leveling material to fill small pores in the slab joints and base layer, enhancing the adhesion of the waterproof layer;
• Polyurethane waterproof layer: Apply polyurethane waterproof coating to form a flexible and durable waterproof membrane that can accommodate slight deformations of the prefabricated slab;
• Waterproof coating edge finishing: Strengthen treatment with waterproof coating at wall corners and pipe roots to prevent leakage caused by improper joint treatment of membrane or polymer waterproof layers.
  The use of membrane waterproofing is strictly prohibited due to its rigidity, which makes it prone to cracking due to deformations in the prefabricated slab.

4. A 72-hour closed water test must be conducted to verify waterproofing effectiveness
After the waterproof layer construction is completed, close the floor drains and drainage outlets, fill the bathroom floor with water (at a height of not less than 2 centimeters), and observe for 72 hours whether there is any leakage on the ceiling or walls of the floor below. If leakage is found, immediate rework and repair are required until the test passes. The closed water test is a crucial step in verifying waterproofing quality and should not be omitted or shortened.

Summary: The core of bathrooms in prefabricated slab houses lies in "waterproof sealing" and "structural load reduction". By implementing double waterproofing, lightweight walls, layered construction, and rigorous testing, the risk of leakage can be effectively reduced, ensuring safe use.