When decorating a new house, many people will find that their bathroom is a deep pit, dozens of centimeters lower than the living room, why is this?
Nowadays, there are two kinds of toilets, one is sunken and the other is ordinary (no sinking). This kind of deep pit refers to the sunken toilet, which is to sink the toilet structure layer partially or as a whole from the corresponding floor at a certain height (generally 40cm) when the main body is built, so that the horizontal drainage pipe of the toilet can be buried in it.
The sunken bathroom can be decorated with a toilet or a squatting pit, and the bathroom plane will not be higher than the living room after the installation of the squatting pit. The position of the squatting pit, toilet and washbasin can be changed according to the design to achieve a reasonable space arrangement. Since there is this pit, it needs to be filled in so that the subsequent decoration work can be carried out.
If there is no sunken bathroom, you can only install the toilet, and the position of the toilet cannot be moved during decoration. If you really want to install a squatting pit, you can only start the platform, so there is no problem of backfilling in ordinary toilets.
First, the backfill volume of the sunken toilet is still relatively large, and lightweight backfill materials must be used from the safety of the floor slab. So how to backfill the sunken toilet, what materials are used to backfill, and what points should be paid attention to in the construction in order to reduce the quality of water leakage in the later stage?
1.Do a good job of waterproofing.
The waterproof height of the wall should be more than 40cm higher than the original horizontal ground to ensure that the upper layer of water seepage will not expand to the periphery, and the floor drain should also be slightly lower to avoid poor drainage, resulting in peculiar smell.
2.Brick partition walls.
The red brick partition is used as the overhead, and the sinking part is divided into several lattices of about 40cm and 40cm, and with such a load-bearing partition, the concrete cushion can be laid on it.
3.Backfill. 
Choose the right backfill material, give priority to the use of ceramsite or coal ash slag, do not press too tightly, naturally, because it is not load-bearing, only to absorb water vapor and fill. The material of the backfill must be good, the money must not be saved, and you must also pay attention not to let the black-hearted construction team backfill the construction waste for you.
4.Arrange the reinforcement and pour the cushion.
After the backfill is completed, a layer of 20cm 20cm steel mesh is laid above the filler to improve the mechanical performance of the concrete cushion, and the quality of steel bar processing and installation and pouring of the cushion is very important.
Second, if you don't want to backfill, is there any other way?
Of course, in addition to this backfill construction process, there are also many people who choose the overhead method. The so-called overhead, as the name suggests, is not to fill the material, directly do a secondary drainage, and then cover the cement board.
The advantage of using overhead is that it can reduce the bearing capacity of the bathroom, and it is also convenient for maintenance, and this practice is more economical. Choose the overhead way to decorate, the bottom of the waterproof must be done, otherwise once the ground seepage or pipeline leakage, the overhead layer will become a water tank.
In particular, pay attention not to forget to install a secondary drainage pipe, through which the water in the pit can be removed (equivalent to a floor drain).
If you don't do secondary drainage, once there is a water leak, it will cause the caisson to accumulate water, and in the long run, it will damage the water pipe and the ground, causing seepage and leakage, and it is very troublesome to maintain.
After doing the above steps, you can normally construct the bathroom waterproof and floor tiles, although the bathroom is a small space, but it is very important, once the construction is improper, it will leave the hidden danger of water leakage, redecoration, compensation for the loss of downstairs, think about it is a headache. If you have any questions, you can leave a message in the comment area! Decoration