Marc wrote:

From all the the advice I've received on this forum and others, I've
pretty much decided to give up the idea of wood on the ceiling. I think
I'll just go ahead and tile it with the same 16' X 16' slate I'll be
using for the floor.

I've also had someone else suggested using western cedar but leaving it
unfinished or oiled so that it can breath. Apparently cedar can absorb
and release moisture fast enough to prevent mold....but who knows....

In a shower???? NO way!