Is the smell of the bathroom the cause of the upstairs residents?

The biggest possibility is that your downstairs neighbor's bathroom is not equipped with a water trap, causing the smell to run up from the sewer pipe, or from the floor drain up, causing them to feel very smelly, under normal circumstances, your house sewer pipe is not leaking if it is not your business.

It is possible that the drainage slope of the drainage pipe is not enough, resulting in the water flow being too slow and the sewage retention time being too long. Or the water flow is too rapid, and the water pressure in the pipe is too high, causing the water level of the backwater bend to be too low and lose its effect. It can also be caused by poor pipe sealing.

Check whether your basin has a trap, my original basin does not have a trap, I think it will be okay to put the water on the top of the lid to die, it will be good to have a smell for a long time and finally add a trap. Originally, there was a small hole in the top of the basin for draining.

The code stipulates that the sewage pipe must be installed more than 2 meters above the sky, so that the smell will run from the sky, not from the home.

There are many reasons for this.

1.The stench of the floor drain came out.

2.There is no water storage elbow in the basin.

3.Clogged toilets.

4.The downspout is cracked.

5.Could it be a leak on the upstairs floor or a dead rat on the ceiling?