How to make a sunken toilet waterproof

The safest thing to do is:

Remove the cold oil waterproofing layer (that is, the black thing) (if any) made by the original building side, and roughly smooth out the uneven and convex sharp corners of the ground and sunken walls caused by the removal of cold oil.

Make a layer of screed with a thickness of less than 5 cm on the ground in the sinking area, pay attention to the slope of the ground towards the downstream, and then brush the waterproof paint twice in the sinking area, especially pay attention to the downstream.

After positioning and installing the water and sewage pipes and circuits (if you use a squatting toilet, you must first get the on-site positioning, and also inform the bricklayer), and then fill the sinking area with relatively small brick waste or slag (preferably slag, but this seems to have to spend money to buy) to a certain height (the height is mastered by the bricklayer), and then the whole bathroom is leveled and sloped (completed by the bricklayer), and then the overall wall and ground of the bathroom are waterproof paint 2 times. Then carry out the wrapping of the sewer pipe (the advantage of this is that even if the upstairs sewer pipe seeps into your bathroom in the future, it will penetrate directly into your sewer along the waterproof layer) and the wall and floor tiles are paved.

In doing so, it is equivalent to carrying out two waterproof constructions, each time brushing 2 times (horizontal brushing once and vertically, pay close attention to the drain and corners must be brushed in place, and be sure to wait for the previous time to dry thoroughly before brushing the second time), in this way, the labor cost will increase, the material cost will also increase, but it can be foolproof.

Sunken toilet waterproofing practice.