Replies

1. 
   calvin | Dec 10, 2009 08:00pm | #1

   First, find out if the tub maker has an add on tile flange.

   Second, if first is no.......dream one up. Much like flashing, you want to repel water.

   Like you wouldn't just put up cement board and expect it to not leak, you put up a "full" flashing behind it. That moisture barrier lips over the tile flange if there. If not, it must lip over something that is sealed to the tub surface.

   In the past I've used vicor to go down behind the cement board, or whatever sheeting behind solid surface as finish.

   Go down over the top of the tub stopping just short of where the finish will cover.

2. 
   Ingleton1 | Dec 14, 2009 11:24pm | #2

   If the manufacturer does have an add on lip for the back of the tub (it is usually just a plastic L-channel) Make sure that they also give you the recommended product to adhere this channel to the acrylic tub. I have tried silicone in the past and it failed to remain adhered to the tub after a year and started causing water leakage. If the manufacturer does just recommend silicone, make sure to scuff up the surface where the channel is to be stuck to using some fine sandpaper and make sure the surface is dry and clean before applying the silicone.

3. 
   DanH | Dec 15, 2009 07:22am | #3

   The old fashioned way is to caulk the joints. May give many here conniptions, but it worked for about 100 years, before they came up with flanged tubs.

   The main problem is that the joint must be tediously recaulked (after thorough cleaning) from time to time, but with modern caulks that's 15 years or so, vs the 5 with the old stuff.

   There's also the theoretical problem of moisture getting behind the tile and running down on the back side, but if that's a major issue then your grout job sux.