Shower & Bathtub leaking through the ceiling

The Problem: After long showers water flows into our kitchen below. Recently my young son took a bath in the corner tub (right next to the shower), running water again for a long time, and then water also began pouring into the kitchen below.

What I see so far:
I've cut open the ceiling of my kitchen and observed the leak coming through the subfloor above. There are several water spots that have appeared on the kitchen ceiling as far as 10-15 feet away from the "pour through" spot.

The spot where the water comes through is located under our tile bathroom floor approximately 2 feet from the tub drain and 3 feet from the shower. We have no evidence of water in the floor of the bathroom. I reached through the tub's jet's motor ventilation door and could touch the floor and it was not wet.

Need: To find the leak and fix it!! Thanks for your help.

It sounds like a drain, but you need to rule out the water supply side as a possibility. You can remove the flanges or escutcheons around the valve handle and the shower heads. Use a flashlight, run the water and look for signs of a leak.

Assuming it is the drain, you are going to have to open up more ceiling. Water travels along subfloor and along joists, which is why you have it appearing in many places. The most likely leaks will be directly under the tub or shower drains. At these locations, there should be an opening in the subfloor, so if you open the ceiling at that spot, you should be able to see something.

One last idea: do these leaks appear during a shower or mostly connected with a bath? If anyone is in the habit of filling the tub above the overflow plate, there is a gasket here on the back of the tub. Check this out.

Thanks. We are going to follow your advice now and will let you know how it goes.

We have eliminated the incoming lines as possibilities.
If it is the shower pan, how would water get to the shower pan? caulk or drain pipe leak or something else?
Thanks.

You can use a long party balloon and plug up the drain on your shower. Push it down the drain (you have to unscrew or pull off the grate first, obviously) and blow it up. Then get a bucket or hose, fill the shower up to just below the curb - don't use the shower to fill the pan up (you're trying to see if the pan is leaking so you don't want the spray or plumbing supply to possibly contribute to it). Let it sit for at least several hours, maybe overnight, and if you don't see any leaks, it is not the shower pan that is leaking. You can put a pencil mark on the wall to show the original height of the water...check it occassionally to see if the water level is dropping. The reason you need a long thing to block the drain, is that (if installed properly) there are weep holes under the surface to allow water that gets through the top surface, but above the waterproof liner to weep out the drain. If you don't get a seal down low enough, then the water will go out the weep holes (slowly).

A pan can leak for many reasons. If it does, then it is usually rebuild time.

Thank you. I'm off to the party section of the grocery store. I'll post follow up in the morning. Also, now I have several sections of my kitchen/great room ceiling that is missing - any tips or top sites regarding my repairing them?
Many thanks.

I am not a plumber but we had this type of problem in our last house - jacuzzi tub was leaking to basement when you took a shower - the culprit = the tile grout was not sealed and basically acted as a sieve and water was entering the basement (from behind the jacuzzi, through the subfloor to the unfinished basement). How I caused this? Cleaning midlrew with the Clorox Bleach Pen - caused eroding/decay of grout. My husband's solution - sealed grout with clear silicone. No more leaking.