What material is good for toilet backfill? Do you have to use ceramsite?

Ceramsite is an artificial lightweight aggregate (lightweight aggregate) with a hard shell, a waterproof and gas-proof glaze layer on the surface and a microporous ceramic body inside. It has good physical, chemical and hydraulic characteristics, large specific surface area, high porosity and strong adsorption and retention capacity. Its surface is porous, angular and rough. It is precisely because of these characteristics that ceramsite is often used to backfill the sunken basement: first, it is light in weight: the thickness of the sunken bathroom is generally 400mm ~ 450mm；; If the material is heavy, it will cause the floor to crack, which is not conducive to waterproofing. The use of ceramsite makes full use of its light weight. Second, moisture absorption: there are microporous ceramic bodies in ceramsite, which can absorb moisture, which is undoubtedly beneficial to the bathroom environment. Third, easy maintenance: because it is easy to dig, it is more convenient to construct when maintaining than filling with other materials. 4. In addition, ceramsite has strong adsorption and interception ability, and good physical, chemical and hydraulic characteristics, which are all suitable for the specific environment of toilet.