I should also add there is tile 31" up surrounding the tub. I will obviously have to remove this.

You would have to make a small hole next to the tile to see if it is cbu or drywall. Most probably it is drywall because the wall around the tub is more like a backsplash in a kitchen versus a shower in a bathroom.

The most important thing is does the tub have a tile flange? If so, then you are in luck. When tubs do not have an integral tile flange, then you install a separate tile flange with silicon caulk, adhesive, screws, etc per manufacturer instructions. The cbu is installed a fraction of an inch above the flange. Nowdays, a surface moisture barrier is installed on the cbu - either a topical paint type (Red Guard, Hydroban) or Kerdi (plastic fabric installed like wallpaper with thinset). The gap between the cbu and the tub is filled with caulk - folks like to use Kerdifix. Then the tile is installed on the wall to where it hangs right over the cbu/caulk gap but doesn't quite touch the tub. Then that gap is filled with colored silicon caulk that matches the tub or tile, and it must be maintained for the life of the tub. Same installation is done for shower pans.

You are going to have to tear out the existing tile. The issue is that if the tub does not have a tile flange, can you add one to it . Maybe you can detach the tub from the studs, install the tile flange, and then reinstall the tub. Then install your cbu.

If you choose to use Kerdi, you do not have to tear out the sheet rock above the tile because Kerdi can also be installed on drywall.

If all else fails and you really need a full shower, it may be better to buy a new tub. A soaker tub is cheaper than a whirlpool. If you don't mind the fab walls, Sterling has some nice tub/shower wall sets. Or you can install a handshower to your existing tub. Many times I wash my hair in my tub with my handshower when I have time to take a bath in the mornings.

So do some light digging at the edge of your tub to see if it has a tile flange. Also, look up your tub's specs on the internet and/or call the manufacturer.

Acrylic tub walls are usually specifically made to go with their matching brand of tubs because of their lock and fit mechanisms.

Search this forum and the John Bridge forum for more specifics and details whether you DIY or hire the work out.

This post was edited by Anna_in_TX on Sat, Dec 7, 13 at 15:21

Are you talking about tiling the walls to make a shower? Or putting an acrylic surround on the walls? If you're doing the latter, then all the waterproofing isn't needed because plastic is pretty impermeable.

Post a photo of your current tub and we can weigh in further.

OK, I misunderstood. Poster wants to install shower surround on existing tub. Some of the acrylic surrounds are nailed directly to the framing. Some are glued to cbu. Cultured marble surrounds and solid surface like swanstone are glued also. But to be safe long term, the tub really needs to have a lip or tiling flange.