why is my bathroom floor leaking?

[kally]

It leaks into the downstairs bathroom and the ceiling in there is about to fall down, or at least we will have to replace some of the drywall.

Upstairs the leaks start when the floor gets wet, not flooded, but just a clumsy kind of water spill. Then it goes through.

We have those big rough slate tiles on that bathroom floor. Could the grout be leaking or something?

[Mrs-M]

DH said you have to (first) start by troubleshooting the problem area and hone in on the location of the leak. He said it could be the base fitting on the tub, the shower pan drain, a faulty toilet seal, or even a pinhole leak from one of the main water pipes feeding your upstairs bath. Unfortunately (according to DH), sometimes you have to open up areas of the drywall in order to ascertain where the moisture is coming from.