First Time Tiler Using DITRA and VersaBond (Maybe???)

[ChadErway]

Long time reader, first time poster. First off, thanks to all the great contributions from everyone. I've learned quite a bit scrolling through all these great threads. I know my question has been, more or less answered, on a couple of threads, but I couldn't find any solid information on dry time. I know many have mentioned that they use Versabond over DITRA without issue, but I couldn't find any drying times and I didn't know if using Versabond-LFT (since I'm installing LFT tiles) made a difference.

I am not a tile professional, I'm just a regular Joe that needs to tile his kitchen. I have purchase the DITRA membrane and after reading over all the information I was planning on using Versabond to adhere the DITRA to my OSB subfloor and then Versabond-LFT to install my Daltile 12x24 ceramic tile.

I just wanted to confirm that would work out okay and find out what the drying time would be since on this kind of installation.

I know there are a LOT of other, better materials out there, but I'm locked into using what's available at Home Depot and am just trying to make the best of my limited options and not ruin everything .

I appreciate any help or advice anyone wants to give. Thanks in advance.

[jadnashua]

You can tile over Ditra immediately after installation. If you're not going to do that, you should wait at least overnight and you'll find you may want to use something to spread your weight out like a small square of plywood while kneeling on it the next day. Before you grout the tile, you'll want to wait at least overnight, and a day or two is probably better...check to see if the grout has any stipulations on it...some may want more time. Before you apply any significant loads (setting your toilet, installing the vanity), you'll want to wait at least a few days, and a week wouldn't be bad.

There are at least four classes of things that can be used as modifiers. Many of them are stable while still wet. Latex, the original and still used with some, needs to dry to be come stable. The cement cures without drying, but if the stuff around it isn't stable, the curing cement can be fractured, preventing it from keeping a good bond.

The industry spec sheets don't make it evident what type of modifier is used in the US. Schluter knows an unmodified works on top of Ditra...they do not know if the modifier will. In Europe, the DIN specs do differentiate those features, so it's easy to list specs, and not have to test all brands and models like they'd have to do in the USA, especially if they ever changed the configuration, so they list ones they know will work.

It is critical to get the fleece bonded to the plywood, and that takes a modified. It is not critical on top of the sheet since thinset does NOT bond to the sheet, only to the tile. https://youtu.be/aubjjQ9DkiY As a result, there's very little stress on the bond...the towers of thinset transmit vertical forces to the floor through the mat that is bonded to the floor, but with the grid, the whole floor acts more like a floating one than one that is bonded to it.

[ChadErway]

Thanks for the feedback, that's a big help.

I'm starting to get a pretty good understanding of how the modified and unmodified works and your explanation sheds a good deal more light on the matter.

My main concern is how long it will take the Versabond-LFT between the DITRA and the tile to dry. It's a couple days then grout, and a week for light to standard use, then that's cool. I've just heard some concerns from folks that the Versabond-LFT would take "a while" to dry, but I don't know if "a while" means an extra day, or an extra two weeks .

[ss3964spd]

I can't imagine that V-LFT takes any longer to cure/dry than does regular Versabond, Chad.

FWIW, I did my entire bathroom floor with Versabond; Ditra (Heat) to plywood, tile (12X24's) to Ditra. I stayed off any newly installed tiles for 24 hours, then only foot/knee traffic for another day. Grouting it quickly wasn't an issue for me (as I'm embarrassingly slow) But I'd want to let the mortar cure for at least two days before grouting.

Inna kitchen, where I imagine you'll be moving appliances about, I'd wanna wait a week after grouting before rolling your Sub Zero across the new floor. And even then I'd probably want to lay down some masonite panels to protect the floor.

[Kman]

With mortar between two almost-impervious surfaces, I'd wait a couple of days. If you need to walk across a traffic area, lay a sheet of plywood over it the next day to walk on. (At $60-70 a sheet, I'd not wear shoes when walking on it, and I'd return it soon after. )

The larger the tile, the longer the drying time.

And if you happen to be using a light-colored grout, you'll want to use white mortar instead of gray.

[John Bridge]

Hi Chad,

The term we use is "cure" when it comes to mortars. In any case, VersaBond LFT will work just fine. Wait overnight after putting the Ditra down, and wait a couple days after installing the tile. Then grout.

Jim's idea of using a piece of plywood as a knee board over the Ditra is a good one. I even move a small piece of two by four around to rest my hand on. It prevents Ditra hand.

[ChadErway]

Thanks for all the great info everyone! It's very much appreciated.

[Shady at Best]

Chad, If you are still wondering. I use versabond a lot when installing ditra on both cement and wood foundations. I think it might be my preferred ditra/kerdi installation thinset although it completely voids the non existent warranty. I will install a row of ditra and then go back and fill it in with a thicker mix of versabond. Then install the next section of ditra and back fill the lugs. I am tall and have no problem reaching across 3 feet and filling it in. I feel confidant walking on it the next morning when I can be done no later than 2pm the previous day. That gives it roughly 17-18 hours to dry before I am walking on it and setting tile. It also holds down the edges and keeps them from curling up.
Good luck