"Don Task" wrote in message
om...
"3GCPO" wrote in message
...

We have an 12'x16' room/add-on that was built off the back of our
house (not part of the original construction), over a well ventilated
dirt floor crawl space. The floor construction of this room is 1"
plywood on 2x8 joist, 16" centers. My wife wants me to ceramic tile
the area.


lots of deflection with this span and framing.

I give it 1 thumb down
to this project as you describe it.

Okay... the other, less favorable approach (more trouble to me anyway)
is to forget the whole plywood, backer board idea... and go with a 1
1/2 to 2" wire reinforced mudbed.



Now you're talking!
I knew you would figure it out.






This would certainly eliminate any
flex concerns. Anyone know of any negative aspects with this approach
(in this application?)
Don

only 1 concern,
the transition to the adjoining room.
I would install a marble or granite threshold.