It's not a matter of slippage. It's a matter that moisture will reemulsify the mastic, and once that happens, your bond is lost permanently, and the only thing holding the tile in place is the grout.

There's been cases where the way the homeowner found out that this had happened was that a piece of grout would come loose at the bottom of the wall, and the mastic would start drooling through the missing grout. In atleast one such case, when the tile was removed, the wallboard behind the tile was clean as a whistle.

So there are no special techniques or tips/materials to help make this bond as water tight as possible? If I'm using a non-sanded grout can I still seal that? Does the sealing help with water absorption? Just looking for something I might do to make it the best situation I can...

Tara

So there are no special techniques or tips/materials to help make this bond as water tight as possible?

Well, you could go over all the tile with Kerdi! :-)

If I'm using a non-sanded grout can I still seal that?

You can, but it still won't be watertight.

Just looking for something I might do to make it the best situation I can...

Well, let me put it this way-- what you heard? The part about "posts saying they've done it several times and it's lasted years with no slippage"-- that is true. You're playing russian roulette with it, but you could go ahead and finish it off and just live with it as long as it lasts.

Thanks Bill!

Unless Kerdi has chocolate in it...don't think I'll try it! :)

I think my best solution is to tell my girls that this is a bath only bathroom...never to splash water and to enjoy the soak! :) If they want to go wild with bubbles, they can do it in my soaker tub! :) Luckily we have 4 bathrooms...the other two bathtubs were tiled directly onto what looks like drywall board to me...they've lasted 9 years...so let's hope in 5 years I'm not replacing 5 bathtub surrounds! :)

Thanks for your help and I'll be back in 5 years to give a report! :)
Tara

I'll most likely still be here. :-)

" put Mapelastic on my blue board before tiling...adding hardibacker or durock would have removed any lip at all on the tub...
lip has nothing to do with what you put behind it.. i don't think you know what "lippage" actually is. Lippage is one tile setting "taller" than the one right next to it.. creating a "lip" taller than it.
Why are you using mastic in a wet area instead of thinset that is made for wet areas? And if you aren't doing this yourself and having it hired, then why are you letting the guy you hired do that?

cindy...it's pretty simple...like I explained...I went to 5 tile stores...they ALL said to use the mastic on the tub surround tiles...I told them I was tiling a tub surround and what would they recommend ....they ALL said MASTIC!! Now, when I go to a auto shop and ask 5 mechanics what I should use to fix something and I get the same 5 answers...do I go searching the internet?? No...I trust them. Like I said, it's been done MANY MANY times this way so I was hoping someone here had some tips on how to help make it work...if a cake has been baked 100x..surely some baker knows an extra tip or two to making it come out better...

Lip does have somethign to do with what you put behind it...I'm not a professional tiler..I'm not versed on the "proper" verbage but when trying to describe the amount of tub "shelf" left after building out the wall that tile is to be set on...Lip sounded pretty good to me...what would you use maybe the word "reveal??" I just happened to choose lip so don't shoot the homeowner...I've done more than 50 % of this remodel...I've been praised for the tile work I've done and that it beats many people they've known who say they know how to set tile...

I just can't believe that no one here has anything encouraging to say in the least...thanks guys.

Tara

Tara, you want me to stroke you or give you accurate information? I've gone alot further than I'm normally willing to go with what I've said to this point, only because I really feel for your situation.

I think mastic is the scourge of this industry, and quite frankly, should be pulled from the market. There are thinsets out now that will give you all the same advantages that mastic gives you (other than being premixed), and none of the disadvantages, with all the strength of a latex modified thinset. Do I think your tile is going to come down any time soon? Hopefully not. I WOULD, however, wager that your bath won't last as long as it would if it were put together properly.

That's my final word on this thread.

Bill...I wasn't looking for another comment from you...I greatly appreciate your position and experience...what is frustrating is that I put this post out looking for SUGGESTIONS not simply affirmation that my findings of what has been done is not the best way...the mastic itself does state that it can be used in tub surround applications...

You didn't have to come and post a final word...this post was not sent for opinions on my misuse of tile terminology or confirmation that the tile has been set in a sub-par manner...it was simply to see if anyone out there who has used this method may have some pointers or tips on what may help..

For instance, would epoxy grout be a better application than the non-sanded acrylic grout...is there a sealant product that would be better to use with this situation..I'm not looking for a stroke of "it'll be okay"..I'm just trying to find tips on the best approach from here on out...

Not one time have I heard anything that would be construed as a suggestion...if you don't have a suggestion on how to make the grouting/sealing/finish of this situation better...than how are you helping me? I came here for help...even asked that the homeowner not be shot and that's pretty much all I've gotten...

I hired the guy who is tiling it (with 30 years exp.) because the tub surround would kill my back...I was injured in a car accident many years ago and I can't do certain positions...tiling a tub surround is not the same as the floors...I am doing the grout because I have to save money...and I take pride in doing a project myself and showing my kids how to do things and be self-reliant...so I came here with the knowledge that mastic has a bad reputation esp. since the removal of VOC's but also with the knowledge that it is still used in MANY tub surround applications and that someone who has used it might share their experience/knowledge on making the grouting the best I can..I thought I was clear on this in the first post...

I've got a house to move, another floor to tile and am sorry if I've offended those who came to offer critique and opinion rather than be helpful.

Tara

I even helped myself today..I read my caulk tube for applications and it said for it not to be used in wet areas...so even a simple...maybe you should use XYZ brand of caulk for a better application would have been nice...I'm not a tile person I didn't know the difference between caulks...that's all I'm asking for is a little help..

Tara

You're upset at me because I've offered my expert opinion, rather than be helpful. Tell me when this makes sense.

I saw your posts earlier but I wasn't going to bother answering you. Unfortunately this has been eating at me for the last few hours.

I told you-- if you want to play russian roulette, leave it up. If it were me, and I didn't know anything about tile, that's probab ly the course I'd take, only because if it comes back down, I've lost it, anyway.

But then on top of it, you want me to give you a way to make it last longer. I don't know of any. You asked me questions, and I tried to answer them as honestly and completely as possible. But that's not good enough for you, You want me to go ahead and stroke you, and then a few months down the road, I'll have someone else in here saying "Well, Bill Vincent said it's okay to do this!"

Sorry, Tara, but that's not going to happen, and for the first time in just over three years of being in here, if I've offended you, I don't apologise.

Bill..of course you've offended me...you continually come on to this post griping about the poor installation and how it will fail...I simply only asked for help from anyone who might have help...you have none..so it would be best for you not to post...

If I read a post and they're asking for help (nowhere do I ask for stroking)...but I really don't know of any help to give I don't add to their frustration by reminding them that they're screwed. I'm sorry you hate mastic...but 8 out of 10 tilers have used it on tub surrounds...those are the ones I'm appealing to..you don't use it so you wouldn't have a suggestion..which is all I've been asking for..

Not commentary.

Tara

Tara, Using mastic in a wet area is against industry standard. I am sorry that the tilers in your area don't care about providing quality installations. We are lucky to have Bill here giving us information on the right way to do things. Hopefully this thread will help someone else avoid making the same mistake. That said, perhaps if you use a epoxy grout and dry the shower completely after each use you will have many years of use out of this shower.
And just so you know, I speak from experience having once installed shower tile using mastic which eventually failed.

I go with Bill's advice...he has the years of experience, plus informs us of the industry's standard. how can you argue with what a manufacturer says their product can or cannot do? don't think the manufacturer hasn't tested the mastic with moisture...if it could handle it, they'd sell even more!!!

those look like expensive pretty tiles...i vote for you to take em down, scrape em, and reinstall (or have someone reinstall). it looks like you're only halfway done anyway. you have all the time in the world, from my perspective, because you have three other bathrooms!! we tiled a bathroom wainscot with mastic, on the advice of the tile store, but not the surround. my hubby, not an expert, always insists on sticky silicone between wall and tub and between tub and floor. of course, he's right, but i hate it that we don't have the skills to make a neat silicone bead. i have removed several 50+ tile walls, regretfully usually because the wall failed not the tile. the skills used to put these in made it possible to install using whatever adhesive on whatever surface and have it remain waterproof for many years. those skills are rarely found anymore...i sure don't have em...so we stick with thinset, sanded grout, and silicone...
you are not the first DIY with egg on your face, trust me.

kren

Bill..of course you've offended me...you continually come on to this post griping about the poor installation and how it will fail...I simply only asked for help from anyone who might have help...you have none..so it would be best for you not to post...

Tara, when you start a topic people are free to chime in. If I begin a thread, I'm happy when any pro will comment! We are here to learn, and often we learn from other's mistakes. I'm tired of incorrect information from tile stores/contractors -- I want someone to answer my question who has no designs on my money.

Sometimes there is no way to make it better. Bill told you that you could take your chances on it...and that might be the most helpful thing to say.

Susan

I thought I read that another reason that mastic should not beused in wet areas is because it re-emulsifies (from the moisture) and therefore can cause mold. I wonder if this is true.

kren...thanks so much...I'm hoping egg is a moisturizing agent and will make me age beautifully through this remodel! :) I don't know how it happened but I am gifted at caulking....it just goes on perfect...I think it's all in the cut of the tip and the continuous flow...no bumps as you pull it across! :) I know I must look silly while doing it, but it goes on like butter! :)

Susan, I told him I appreciated his experience...but I did not come here to ask for a professional to restate exactly what I had already stated...just no need in it and while I may be an expert in other fields if someone is asking for help and I really don't have any I don't go restating the problem...he could have easily told me about a caulk that has special additives to prevent mold...never knew about those because I've never dealt with tub surrounds before...that would have been helpful..or he could have recommened a top notch sealer as mentioned below in comments I found on John Bridge's site...these people tried to help and I appreciate that...I just don't see any help in restating the problem...I think I did that well enough.

I just won't accept there is nothing to do when it's been done time and time again and the Mapei mastic says it can be used in wet areas except where there is standing water like a shower pan floor...so I did some more researching...and here is some good info for anyone else in my situation..I won't be the last I'm sure..and I'd like to see someone get more help when they go looking..this one deals with a shower surround which to me is much more a risk than a tub surround that is used for baths...my girls don't like showering in a tub...

Seriously, mastic can be made to work in a shower. Mastic simply cannot be allowed to remain wet. If it does, it re-emulsifies and the tiles come off. Keep the shower dry and the grout well sealed, and you can delay that for a long time. Also, bear in mind that the bottom 2 feet of the shower are the most at risk. You could reset those, or wait for the problem to emerge, then reset them.

I wouldn't tear is down just because it might not last as long as real thinset. It could easily last for a long time. I tear out older mastic showers all the time that are still sound, only the homeowner wanted a different look. You may be a lot older when it needs to be re-done, and you may want a different look by then.

Also, I tore out a 15 year old tub shower a few weeks ago that was set with Mapei Mastic.Other than the fact that the grout was milewing due to no vapor barrier,this thing was perfect.The Mastics have been improved even more since then.

klark I think squeegin' is good, but IMHO sealing the grout is much more important. You can almost (almost) completely seal out water with a good sealer if you maintain it on a regualr basis. With a little diligence I think you can make that shower last as long as you are in the house.

First off,be absolutly Thankful that it was a Mapei product you used and not something else.
I have used many Pallets of Mapei Mastic commercially and it is the best out there bar none ,no exceptions!!

All those help me...I don't mind being diligent with sealer..so I'm off to find a better product for sealing and will diligently keep it applied...to me that's much easier than redoing the tile..my back can't handle it and my bank account is handling two mortgages right now...so a $5 bottle of sealer a couple times a year will do me just fine..

Tara