Adjust the toilet ceiling and have residual water

Since the water pipe is a factor of age and water pressure. The upstairs bathroom has not been used, which may also lead to water leakage in the water pipe joint, which is generally caused by the upstairs waterproofing is not done well, resulting in water leakage and water seepage. Considering the water seepage of the upstairs water pipe, in this case, the upper part of the bathroom must be dry, because the upstairs water pipe is buried underneath, and the water leakage will penetrate downward.

You can test the water pressure upstairs, if the water pressure drops significantly, there must be a leak in the water pipe or joint.

The main consideration is the water leakage problem caused by the upstairs waterproofing. You can remove your own ceiling gusset. Check to see if the top of the bathroom is damp.

If this is the case, it will be a bit troublesome, and you have to communicate with the upstairs and ask the upstairs owner to come down to see the situation or take pictures for him to see and discuss the solution. If it is really a leak in the upstairs water pipe joint, it is generally necessary to dig the upstairs bathroom and re-do the waterproofing. If the upstairs owner can't communicate, you can contact the property to help solve it and let the property go to them to solve it.

If it's not water seepage upstairs, then it may be that the bathroom exhaust fan doesn't have an air outlet, resulting in a large amount of water vapor condensing on it when taking a shower, in this case, you only need to deal with the air vent of the exhaust fan. In short, don't be irritated when you encounter such a problem, find out the problem, and solve the problem is the key.

It should be caused by water leakage upstairs, it is recommended to find the property as soon as possible!