I should have read this before starting...

[aaronspang]

This site has a ton of info. Of course I found it a little too late for my first bathroom renovation last year. But I'm hoping that I can renov bathroom number 2 correctly now and go back to fix bathroom number 1.

I made the fatal (at least that is what it sounds like!) mistake in June of 06 of putting tile (9"x12") above my shower/tub in the bathroom overtop GREENBOARD using a pre-mixed thinset. I had reservations doing it, but got the word from 2 guys (carpenters that do lots of house work) that it would be fine. I know, I should have listended to my instincts. Anyway, 2 questions have come out of this for me:

1. Can I (and how) remove the tile from the greenboard and reuse it? How can that be done, and is there a way to remove the thinset off the tile if there is any left? I understand that I will have to sacrifice a few tiles in doing so, but if I can reuse the majority, I would be real happy.

2. I was thinking of putting up a 6mil vapor barrier, then 1/2 CBU for the tile to adhere to. Then I read about the RedGard method. Any thoughts on which is better? Since this is a tub and not a standard shower pan? Thanks!

[Rd Tile]

1. It's done already, leave it alone, unless you see problems, seal the grout and make sure the caulking is always kept up in good shape, redo it only if you have to.

2. For the second tub, either a barrier then CBU or CBU then the Redgard, don't use a barrier if using a waterproofing membrane over the CBU, it will be fine either way, but waterproofing it is always better.

Oh, and thinset this time eh.

[aaronspang]

thanks for the quick reply Rd. It almost hurts walking in and seeing the walls, even though they look pretty nice.

I did use Thinset, but it was pre-mixed. That's ok for shower walls, isn't it?

When I removed the old tile, there was mold on the stud and back of the closet wall behind. It needed done. I did quite a few things wrong as well that I hate to admit to, but I guess it helps to get things done correctly. Ok, here is the last BIG mistake I made.

I could not get a self leveling compound to level the floor correctly in the bathroom, mostly because I didn't know that you pour and leave, and I didn't block up all of the "holes" where the floor meets the wall. So I have 3/4"-1" of a concrete slab in the bathroom as the subfloor, and I tapcon'ed and thinset 2 pieces of 1/2" hardibacker to the slab to use as a substrate for the tile. OK, stop the laughing. I realize how stupid this was, but I was on a time line and I didn't have any other help, so I hurried things along. Should I:

a. remove the old tile, demo the floor and replace with 3/4" plywood?

b. remove the tile and try to use an SLC again but with dams around the room to prevent leakage into the ceiling below? The caveat here is that I have the toilet flange to take into consideration. Can't have the SLC create a floor higher than the toilet flange.

Thanks again for your help here. The second bathroom will be great! Because I screwed the first one up. Beauty of owning a house!

[Rd Tile]

Acually no, the pre-mixed isn't thinset at all, just a type of mastic with sand in it, shouldn't be used for anything, if you ask me, that said, inless you see or find any moisture getting to the substrate, leave it for now.

As for the floor, I assume tile already has been set here and if so, is it in good condition still or are there problems?

[aaronspang]

WOW, another huge mistake on my part (about the pre-mixed). Thanks RD. It shouldn't say Pre-Mixed Thinset if it really isn't. I guess everyone mixes their own thinset. Good to know. The floor is ok. It squeaks a little, but it looks great and really doens't have any problem. No cracking or anything, at least not yet. Probably should just leave it until I need to do something about it. Right? Thanks again.

[ddmoit]

Don't feel too bad about your mistake, Aaron. It's borderline fraudulent that those companies are calling their product premixed thinset. At the very least, it's an abuse of the language. I'm glad you found us.

[trecile]

The name "premixed thinset" is an oxymoron. You cannot premix something that sets up by process of a chemical reaction as real, cement based thinset does.

[MadisonRenovations]

Um, if it's sanded mastic (aka "pre-mixed thinset") then couldn't the tiles be cleaned by soaking in warm water?

---mike...

[jadnashua]

If you got the tile off without breaking it, then yes, you can soak and wash or scrape off the mastic. the longer it sits in the water and the hotter it is, the faster it softens up (great thing in a hot shower, now isn't it ).

[Bonus]

Have to say I'm a little concerned about a tile floor 'squeaking a little'. But until it fails enjoy it...

[cecicela]

what about this is bad? Is it that the hardibacker is nailed and thinsetted to the concrete slab? what should have been the correct method?

I could not get a self leveling compound to level the floor correctly in the bathroom, mostly because I didn't know that you pour and leave, and I didn't block up all of the "holes" where the floor meets the wall. So I have 3/4"-1" of a concrete slab in the bathroom as the subfloor, and I tapcon'ed and thinset 2 pieces of 1/2" hardibacker to the slab to use as a substrate for the tile.

[Brian in San Diego]

No hardibacker or other cbu on concrete slab.