Hey Everyone,

I am hoping to get some opinions on a fundamental tiling question, my situation, as well as my plan.

I have an old cast iron tub in a second floor bathroom that I would like to keep. The tub does not have much of a tile flange (maybe a quarter of an inch at most) and it did leak past a 3-piece plastic surround (but I blame that more on the surround).

Anyway, I would like to tile around it and have read about different ways of dealing with the lack of much of a flange. My plan, if I can, is to put sheet metal down behind the tub on the three wall sides rising up 6 - 8 inches above the tub and then caulk between the tub and the metal. I then plan to use tar paper and asphalt roofing cement to create a vapor barrier which is sealed to the tub itself and then rises up the wall. Next would go the Durok (with an eigth or quarter of an inch of space left between it and the tub and then the tiles with a final bead of caulk seperating the tub from those materials.

My questions are: How does that sound? Has anyone had experience with this method? Is the metal a good idea? Is it necessary? Is it even wise to try and use a tub like this on the second floor given the difficulties the mini-flange presents?

The fundamental question I have about tiling is in regards to the vapor barrier placed behind the Durok. My understanding is that it is designed to catch any wayward moisture and direct it back towards the tub. What I don't understand is: If you caulk the space between the Durok / tile and the tub itself, how does the moisture get back to the tub? Logic tells me that keeping moisture in the tub is also going to keep it out. I don't understand where that moisture is supposed to go.

I appreciate your time and insights.

John