How to Deal with the Sinking of Mobile Toilets

The treatment methods for the sinking of mobile toilets can refer to those for sunken bathrooms, mainly including backfilling and overhead installation.

Backfilling Treatment

• Ceramsite Backfilling: Ceramsite has a honeycomb structure, is lightweight, and imposes less burden on the floor slab. It also offers sound absorption, thermal insulation, and heat insulation effects, and can buffer the sound of flushing from upstairs and pipeline noise. However, ceramsite is prone to absorbing moisture when exposed to dampness for a long time. If the construction is not standardized, there may be odors, and even local settlement may occur due to internal looseness, which can damage the waterproof layer and pose hidden dangers. The standard practice is to first build a井-shaped (grid-shaped) structure on the ground with red bricks and then fill and level it in layers.
• Backfilling with Backfilling Treasure (Foamed Cement): Foamed cement has strong fluidity and can fill every corner during construction, including areas around corners and pipelines. After solidification, it forms an integral structure with no obvious voids, has a low probability of settlement, and excellent compressive performance, which is conducive to later tile laying and sanitary ware installation. However, it is relatively expensive, increasing the renovation budget, and when repairing pipelines later, the integral structure needs to be destroyed, increasing the construction difficulty and cost.
• Charcoal Residue Backfilling: Charcoal residue is cheap and lightweight and has certain water absorption and moisture-proof capabilities. However, there may be hidden dangers when used in the renovation of some old residential areas or those with tight budgets.

Overhead Installation Treatment

• Advantages:
  • Convenient construction. It only requires proper support for the overhead slab at the bottom of the sunken box, such as using bricks to build supports, and then laying tiles, binding steel bars, and pouring concrete to make the overhead slab, which saves time compared to backfilling.
  • Relatively low cost. It eliminates the step of material backfilling and saves on the cost of backfilling materials.
  • Avoid odors caused by water absorption of backfilling materials. If there are problems with waterproofing or pipelines that cause the backfilling materials to absorb water, strong odors will be produced over time.
  • Reduce the stress on the overhead bottom slab. For standard backfilling, ceramsite or cinder should be used, but many decoration companies directly backfill with construction waste to save money, making the backfilling material too heavy and possibly causing the bottom slab of the sunken bathroom to crack due to excessive stress.
  • Convenient maintenance. When the internal pipelines are damaged or leak, only the overhead slab needs to be removed for maintenance, while backfilling requires clearing out the backfilling materials for maintenance.
  • Avoid damage to the waterproofing inside the sunken box during backfilling, which can lead to water seepage on the inner walls of the sunken box. Overhead installation only involves making an overhead slab on the sunken box and does not damage the waterproofing on the inner walls and bottom slab of the sunken box. During backfilling, sharp objects may damage the waterproofing.
• Points to Note: The secondary drainage floor drain inside the sunken box must be installed and installed properly.