So this time I went through the hallway.
Used a stud finder, measured for the hallway trim, cut away the drywall and what did I find?
A whole mess of plaster stuff.
Yes, it seems that our plumber really
laid in the durabond nice & thick around the outside of the tub after it was installed, which is of course why it doesn't creak around the outside rim of the tub, just inside that rim.
I thought I could chip away at the mortared in rim, but I had even less room to maneuver than from the closet.
We just couldn't chip through it.
The the DH has a flash of brilliance. Remember the speaker installation? Well HE did. The second speaker we cut into the ceiling was a bummer because we ran into the plumbing. The plumbing for the... wait for it... yes! The Bathtub.
Hell, we already had a hole cut and everything.
So we took the speaker back down, poked and prodded with a wire coat hanger and made sure we had enough room to poke some foam in there. It looked good, so I made a similar 'apparatus' and taped the clear tube to the wire hanger, stuck both into the hole, and then attached the can of foam. (*This time we used uber-expanding foam just in case.)
That white plastic thing behind the PVC (with the fins) is the bottom of the tub.
I stuck the tube and the wire all the way in and basically let it empty itself. When I thought the can was about 1/4 full, I started pulling the tube out of the hole.
The thought is this: if it over expands, it will run out of the sides and towards the edges of the surround, and there's lots of space under the tub wall that faces into the bathroom (the side that you step over to get into the tub.) At least that's the plan....
I'll let you know how it goes after it cures overnight.