Best thinset over Kerdi and Ditra

[tiffanp]

What would be the best thinset for the two materials. The floor is concrete and the shower walls are kerdi. Both are followed by travertine limestone. I was going to use Custom Building Products versabond. I used the versabond for the kerdi install and it seemed like it worked well. I also was curious about a product from protecto wrap which is also an AFM.

[Jaz]

You are supposed to use unmodified thinset to install tile over Ditra and Kerdi. You were not supposed to use VersaBond to install Kerdi if it was over commonly used backers for showers. Best bet is to find Ditra-Set thinset if available where you live.

Jaz

[tiffanp]

I read that Versabond was OK to use in the Kerdi book on this website because it has very little modifier in it.

[Jaz]

Yes OK. John is worried that Kerdi may not stick good enough, and he is also worried that porcelain tiles will not bond good enough to Kerdi or Ditra. No argument from me really, just try to let everything dry a little longer before going to the next step. I used high quality modified thinsets to set tiles over Ditra for 2-3 years before the rep told me I was wasting money.

Schluter however does not recommend the use of modified under Kerdi and over both products.

Jaz

[tiffanp]

When you say if using Versabond let it dry longer. How much time should I wait?

Thanks for your help!!

[Jaz]

Well.......I don't think anyone knows? You see modified thinset require air to dry whereas unmodified thinsets dry by chemical reaction. Generally we just wing-it and suggest and extra day or so if possible.

I remember moving refrigerators back onto newly installed tile floors just after grouting, which means at least part of the tiles had been set the day before. That was when I was using the high quality modified I mentioned before, usually it was Tec's FullFlex. So, you should be fine, but give it an extra day if you can.

Jaz

[cx]

Originally Posted by Patrick

I read that Versabond was OK to use in the Kerdi book on this website because it has very little modifier in it.

There's also a disclaimer in that book saying that Schluter does not condone the use of that modified thinset, Patrick.

I use it. It works. I don't wait any extra time, but I'm real slow anyway.

You got real big tiles you might wanna wait longer than for smaller tiles, as Jaz suggests. I wouldn't move a refrigerator over my new floor installation right after grouting no matter how I'd set the tiles. Just wouldn't wanna take the chance. But I might walk on it.

My opinion; worth price charged.

[LatCSRNC]

I would opt for rapid set thinset over ditra and kerdi. You get the latex modified you need with porcelain tiles and you get the quick drying time you ned also.

Gary

[sandbagger]

a high-quality dry-set works just fine, especially if you take a little extra time to back-butter the tiles. I tried a couple and settled on Kerabond.

I think I saw somewhere that one of the reasons that dry-set works well here is actually the lack of air what with the thinset sandwiched between plastic and porcelain. The point was that there is much less drying effect and more curing. allowing the curing process to run its full course created a much stronger finished product. Kinda made sense to me.