Once you spot the bathroom leak to downstairs ceiling, it’s best to check the areas you can access easily first, such as the water supply lines to the commode and to the sink, the wax ring underneath the commode, and the sink trap. Typically, the leak occurs at the plumbing connection at connector joins located in drainpipes or where your water supply lines attach.
If the water leaking from second floor bathroom comes from water supply, figure out which one is damp by running the fingers over the supply lines. Meanwhile, for trap leaks, check the drain trap underneath for drips and turn on the water in your bathroom sink while doing so.
If bathroom leak to downstairs ceiling comes from the leaking wax toilet ring, it may not be spotted on your bathroom floor. Even so, you don’t need to worry at all since fixing this problem really is easy.
Meanwhile, if you can’t spot the bathroom leak to downstairs ceiling elsewhere, simply pull the commode and then replace the wax ring. Once the commode is removed, you may find any sign of dampness around your toilet flange if the leaking wax ring is the cause behind your bathroom leak.