[Bud Cline]

Is there any support under that seam in the plywood? Doesn't appear to be looking from here. I think I would first use some PL adhesive in an effort to join the two plywoods together, then I would agree a good "stop-gap" temporary repair would be to use 100% silicone as suggested.

But...no more than two years then you have to take it all out and do it the right way - the clock is ticking. Promise?

By the way...that is also the wrong mesh tape that was used tere.

 

[Bud Cline]

Pl adhesive?

"PL" adhesive is a premiere construction adhesive, basically the same as Liquid Nails but in my opinion a better product. The label will say PL-200, or PL-400 or something like that. Try to force some in the crack between the two plywood's then smear some on top of the plywood bridging the crack. After that dries...tile it using 100% silicone.

 

[Bud Cline]

Dat'l work!