Houston, We Have A Problem

I don't think Houston can help, but we DO have a problem.

We have two bathrooms upstairs, the master and a second one. They back up to each other with the pipes/faucets in the common wall. The second bath is your typical one of bathtub width with the toilet right next to it. Over the last several weeks, it's been evident to Nick and I (Marty uses the master one so wouldn't know if we didn't tell him) that something's very wrong! The floor in front of the toilet, and perpendicular to the bathtub has had a bulge developing...as if a 2x4 were beginning to protrude. Yesterday, we decided it was time to determine why. I had/have all these horror images from a recent episode of "Disaster House" where the tub falls through the floor to the bathroom below. Also of note, is that when standing in certain areas of the tub, it's begun to squeak when you move around - this can't be a good sign.

Marty grabbed his tools and first thing removed the toilet, setting out into the hallway (with it's 20+ year old carpet-I'll come back to this) and then started pulling up the linoleum. This is how it looks. The faucet end of the tub is at the right, and toilet location is obvious. I had him cut the linoleum straight across from the edge of the sink cabinet. That's plain old ordinary plywood that was under that linoleum, and it's wet, very wet. Yeah, probably a bit of mold too but I don't panic over such things. Under the plywood, is the original (1966) ?asbestos?-laden tiles. Marty removed the bit of plywood that was around the toilet area and has ruled out any leaking from the toilet. So....where else could the water be coming from? A) the pipes in the bathrooms' common wall could be leaking and seeping under the tub. The floor does slant just a little so would be pooling on that left side. B) the bathtub drain could be eroded and leaking. The floor was still too wet this morning before Nick & I showered to determine if any new water added to the area after we showered...but interestingly, right along the side of the tub for a very evenly spaced 6-or-so inches it is wetter than when you get out further...but it's like someone set a ruler down and drew a line - straight across! C) on the other side of the left wall is my craft room. The back/exterior wall has a ~5' window 4' from the floor. It has leaked in the rain since we had vinyl windows put in 10? years ago, but I didn't think it ran down the wall...until last year when we had really heavy rains and I moved Marty's mom's old sewing machine (in it's carrier) and it was stuck to the carpet and underneath all black. We didn't investigate that further, just pulled the machine away and used towels at the window to sop up the water until Marty could go out and see if the window needed some caulking. With that in mind, did more water pour in some how within the walls and find it's path through to and under the tub? Seems a little much for me to think possible. There has also been two 2-drawer file cabinets in that corner of the craft room and moisture has been under them. I've moved them out of the corner and this is what I find.
(I don't know why Blogger turned this sideways :S ) If you tilt your head to the left, that would be the correct orientation with the common wall with the bathroom on your right. Or you can pretend you're looking over my desk and the common wall is to the back/top of the pic. Only in the very corner is there still some dampness. The black stain is where the old sewing machine had been. It may not be mold, but the black color of the cabinet dye that has leached off.

If it's the C option, then there's also the possibility that from wherever the water is entering to get into my craft room it's entering and traveling both down the exterior wall, and across the ceiling exiting near the ceiling light causing that ceiling leak! Hmmmm, perhaps we've narrowed the long-pursued ceiling leak cause. Would sure hate to tear out all the bathroom tile, tub etc, to find out it's a roof-related issue.

I wonder if any/all of this should be an insurance issue? And if we can't figure out where it's coming from, who do we call? A plumber? Roofer? I'm clueless at this point. We will likely have to remove the wallboard from the craft room side (so long design wall - for now) as it would be the least expensive for of 'de-struction' for now. We would at least be able to see if the water's from the exterior side, or from the bathroom side.

Oh, I almost forgot. That toilet having been set on the carpet in the hallway...well, Marty had flushed it prior to removing it and after turning the valve off, but it still had quite a bit of water in the tank, so having sat on the carpet, that water drained into the bowl and then drained onto the carpet, so the carpet was very wet, and there's a toilet-base shape from the gunk around the bottom of the toilet - nope, no one thought to protect the carpet. Good thing the carpet is so old I don't care, but ... even so...