How to Renovate Indoor Mobile Toilets

The renovation of indoor mobile toilets should be selected based on the drainage method (same-floor drainage or inter-floor drainage), as detailed below:

I. Renovation of Same-Floor Drainage (Sunken Bathroom)

Same-floor drainage allows for greater flexibility in renovation since the pipes are buried within the sunken area of the floor in your own home. You can directly relocate and adjust the position of the drainage pipes without damaging the floor structure or needing to coordinate with the downstairs owner. During construction, pay attention to the following:

1. Pipe Slope Control: Ensure that the slope of the new pipes meets the standard of 1%-3% to avoid poor drainage or unpleasant odors.
2. Sunken Area Waterproofing: After renovation, perform secondary waterproofing on the sunken area and install a secondary drainage outlet to prevent water accumulation and leakage to the downstairs.
3. Backfill Material Selection: Prioritize the use of lightweight materials such as ceramsite or foamed cement for backfilling to reduce the load on the floor and lower the risk of cracking.

II. Renovation Solutions for Inter-Floor Drainage

Inter-floor drainage pipes are located on the ceiling of the downstairs unit, requiring coordination with neighbors and careful construction during renovation. Common methods include:

1. Pipe Displacement Device Method

   • Applicable Scenarios: Small-scale, short-distance relocation (10-40 cm).
   • Construction Points: Reserve a drainage slope of 1%-3%, but be aware that the flushing effect may decrease and the risk of blockage may increase due to insufficient pipe bending radius. It is recommended to use a straight-flush toilet and regularly clear the pipes.

2. Floor Elevation Method

   • Applicable Scenarios: When a larger relocation distance is required.
   • Construction Points: Elevate the floor by building a platform or using lightweight bricks, with the height covering the slope requirements of the new pipes (usually 10-15 cm). Note the following:
     • The floor slope should be uniform to avoid local water accumulation;
     • Round off the edges and lay anti-slip tiles to reduce the risk of falls;
     • Reserve inspection ports for easy maintenance later.

3. Wall-Hung Toilet (Back-to-Wall Toilet)

   • Applicable Scenarios: When the pipe position is close to the wall.
   • Construction Points: The water tank and drainage pipes need to be embedded in the wall, which involves a large amount of work and requires damaging part of the wall. Note the following:
     • Confirm that the wall is non-load-bearing or use a special steel frame for reinforcement;
     • Use rubber sealing rings at pipe connections to reduce the risk of leakage;
     • The floor still needs to be partially elevated (about 5-8 cm) to hide the drainage elbow.

4. Re-drilling Holes in the Floor for Relocation

   • Applicable Scenarios: When other solutions are not feasible.
   • Construction Points: Coordinate with the downstairs owner to re-drill holes in the floor, lay new drainage pipes, and perform formwork work (use cement mortar or foaming glue to seal the holes). This solution is difficult to construct, costly, and may affect the structural safety of the floor, making it difficult to implement in most cases.

III. Key Considerations

1. Drainage Slope Priority: For inter-floor drainage renovation, strictly calculate the slope to avoid poor drainage due to pipe bending or increased length.
2. Neighbor Coordination: When construction involves the ceiling of the downstairs unit, communicate in advance and sign a written agreement to clarify the division of responsibilities.
3. Compliance Check: Before renovation, confirm whether it violates property regulations or building codes to avoid later rectification.
4. Long-Term Cost Assessment: Large-distance relocation may increase the risks of pipe blockage and unpleasant odors. It is recommended to prioritize solutions that have the least impact on daily life.