Help with tub conversion...

[Sisyphus]

I have taken on another project that I have questions about, this one is a bathroom. I can't seem to upload a picture but the tub is a jaccuzi style without the jets or holes. It sits on a green rectangular lip of counter top material that butts up to three walls of an alcove. The average horizontal distance from the tub perimeter to a wall is 3". The height from green lip to the uppermost part of the tub perimeters top surface is about 1.5". The appearance is that of a channel running around three sides if the tub-no good if a shower is going in there. I built this myself for only tub use but now have to change it to deal with shower spray. We want to tile the walls and tub surround. My options seem to be:

1) Build up the green lip horizontally so that the tiling would come flush with tubs top surface. Would the ensuing water puddling from showers be a problem? How should I build the surfaces to minimize potential water leakage (overlap sequence) and I assume there should be silicone caulk between the dissimilar tile and fiberglass tub materials to allow movement. The lip is robust and I would use 3/4" plywood under Hardyboard with a plastic liner somewhere in the mix but I don't quite know where.

2) The above but with the build-up surface sloped toward the tub to permit some water shedding. I think this would not look very attractive and probably harder to do.

3) Build a vertical false wall up to the tub edge and tile directly onto that. The tile would make a right angle with the tub upper surface. This would generate a shelf up where the tile stops at the top.

This was a bit long but I wanted to get all the issues out at once. There is also a window which the tile would have to go around but that only gets a bit scary with option 3. If anyone has some ideas or experience with this I would much appreciate some wisdom thrown my way.

Thanks.

[hj]

Those tubs are not really designed for a shower installation, but if you insist the only proper way is to build the deck up to a point level with the tub rim with a slight slope towards the tub. Then tile over the rim of the tub using a bullnose, or corner, tile to give a finished edge to it.

[jadnashua]

I'd build the walls out so that you could tile new ones so they overlap onto the flange. www.schluter.com has a trim piece that you could use as an expansion joint that would not require any visible caulking - Dilex. The manufacturer of the tub may sell, or there are some generic versions of a glue-on tiling flange for this type of tub. You could use Kerdi on the walls and use Kerdifix (a urethane adhesive sold by Schluter for their stuff) to adhere it to the tub surface which should prevent moisture from getting into the walls. Kerdi is a surface applied water-proof membrane that you can tile to. The combination should keep things watertight. Kerdi goes up sort of like wallpaper, except you overlap the seams and you use thinset rather than wallpaper paste to apply it to the wall.

Check out www.johnbridge.com for help on tiling.

With the change to a tub/shower, the valve probably will need to be upgraded to the current code which requires anti-scald technology in it.

[Sisyphus]

Oh yes it will definitely have a pressure balance valve but will feed through the existing dual valve hot/cold tub hardware-just to keep up appearances. So I take it that a level build up will hold water too long and that a slope is needed, or I should just go vertical with the tile. Well that should be interesting.
Any other advice is always welcome, this will take a while.

Sis

[hj]

Oh yes it will definitely have a pressure balance valve but will feed through the existing dual valve hot/cold tub hardware

What does that mean? I hope it means you will use a "remote" pressure balancing unit ahead of the existing valve, but you should know that most of them have very small ports and thus give fairly low flow rates.

[Sisyphus]

Yes it means a new valve as in new plumbing. What I think I can do is instead of plumbing the tub water to a single faucet without an intervening H/C valve, as in modern setups, I can plumb to the existing faucet which has H/C handles but just have the mixed water come through one permanently open valve. Yes it seems too much, maybe silly, but the intent is to have an old looking bathroom with the modern anti-scald plumbing. I think it will work fine and will satisfy the missus as well as safety.
My house is a 1909 arts and crafts which I have been re-habbing for over 10 years. So far I have been successful at hand crafting wood and plaster repairs and replacements to make the house look kept-up-old, fooling many visitors into thinking the woodwork was original. I want to keep that going with the bathroom.

Still can't upload a picture. Oh well.

[Sisyphus]

Been a while as money dried up but now getting back to it. Bought fixtures and a balance valve. Finally decided with a local rep/pro to build up deck with plywood to just above flush with tub lip. I heard all the advice; cement, SCHLUTER foam, shouldn't be done this way or that way...sounded like my asking advice on insulating my knee wall attic. Five pros gave five ways to do it, all saying theirs was THE way to go.
I'm holding my nose and going ahead with my best instincts. I tend to over-kill on things I'm not comfortable with so I think it'll be good.
Left is before the big work, right is the balance valve with hammer absorbers roughed in.

[jadnashua]

While you've got the wall open, why not put in real hammer arrestors? Those will quickly fill up with water and the only way to clear them is shut th ewater off and hope.

[hj]

Are you still going to pipe that valve to the old tub filler? If so, you should completely disable the old valve so it cannot be shut off. Otherwise your next question to us will be why you cannot get either hot or cold water to the other faucets. And, unless you put the cartridge or bypass plug in your new valve, you will be asking that same question sooner.

[Sisyphus]

To Jad... are these not real? Were you referring to the larger version? And don't they all fill at some point?

And to HJ... Bypass plug? Per the wifes wishes, and I don't see why it shouldn't work, the H/C pipes from the basement branch just after shutoffs, one set (shown) go to the mixer the other to the previous tub filler hardware;valves and faucet. My complaint was that the mixer is out of the tub pathway and may allow the dreaded scald if a toilet is flushed. I was out-voted. But even this set up has all the necessary components to work it seems to me.
I ended up deciding to level-up the deck to the tub with glued layers of plywood. It is rock-solid that way and will only need the thin-set/membrane/thin-set/tile to finish it off.

[Sisyphus]

Slowly but surely. Decided on Schluter-Kerdi product to proceed. HardiBacker is up over insulated walls and plumbing is mostly done. Found a neat device to plug supply pipes during pressure/leak testing. Just pushes on like a cap but can be removed with plastic collar and pipe end is suitable for sweating. Came in handy as I could not complete deck faucet install until tiles in which would come last and space was tight. So I just lined everything up for later, capped the pipes, checked for leaks, and will finish the faucet when the tiling is done.
Pictures of HardiBacker and plywood filler around tub on top of old, now sanded, green deck with top beveled to shed water into tub.