Vapor barrier behind pre -fab shower surround?

[TerryT]

I have recieved a few responses in my earlier posts on tub surrounds. I appreciate all of who helped. But, some say put a vapor barrier up. I know this is used behind cement board before tiling, but I'm using the large surround kit which is water proof already. So, is there indeed a need for the VB, or is it overkill? If it is needed will it run down the wall over the tub flange? If so, since this area will be caulked either way, how would any possible moisture get passed the bottom of the vb and allowed to escape in the tub if it is caulked? Hope this makes sense. Thanks, TerryT

[Randyj]

I'm sure everyone on this forum has his/her own approach to every project. So far I've done really well at simply following instructions that come with tub/shower kits. I've never put a moisture barrier behind a plastic/fiberglass surround...only tile...and have never had to go back to repair any mistakes in the 30+ years I've been piddling with this stuff. However, a piece of plastic or roofing felt is mighty cheap insurance.