Thinset/Dryset combination for Ditra

[H-man1]

Thanks again, guys. I got a good jump on setting the floor this weekend. Below is a picture of where we left it last night. I think it is turning out very nicely.

[v4Brad]

Floor looks great Homer. So did you find a premium dryset or did you use Versabond?

[H-man1]

I called all over, and no one in our area carries a premium dryset. One of the major manufacturers of mortar actually has their world headquarters not far from where I live, but they don't answer their phone (useless). So, I used versabond, and let it set for a week before grouting. It came out great.

[organic_donna]

Trask,
You said, "I used Ditra set with additive under the matt". What additive are you talking about. I don't mean to ask such a ignorant question. I'm new to tile installation.
Donna

[Brian in San Diego]

Donna,

Don't know if Trask will see your question or not since his repy to this thread was two months ago. I can tell you what he means. The "additive" he refers to is a latex mixture that is sold by the various thinset manufacturers. Laticrete makes one called Admix 333. Lowe's carries a similar Laticrete product called Megabond additive. It is used in lieu of water to mix the thinset. It turns and unmodified thinset into a modified one.

Brian

[organic_donna]

Thanks so much Brian for always answering my never ending questions. That information is really helpful.
Donna

[organic_donna]

Brian,
Just to be sure....Ditraset with additive goes UNDER the matt and Ditraset with water goes on top of the matt.
Donna

[Brian in San Diego]

Donna,

It depends on the substrate. If you are installing over a wood floor, then the additive is called for. If you are installing Ditra over concrete, Ditra Set would be mixed with water only both under the Ditra and on top of the Ditra. Please take the time to go to the Schluter site and download the Ditra Handbook. It should answer all of your questions.

Brian

[organic_donna]

Brian,
It's over concrete and I have already given the instructions to my contractor. So...just plain Ditraset mixed with water both under and over?
Donna

[Brian in San Diego]

Yes. If you have additional questions regarding your project...take them back to your thread we're cluttering up H-Man's thread with your project questions.

Brian

[organic_donna]

Sorry, H-man1

[H-man1]

I thought I would resurrect this thread from the long lost bygone era just to report back. As I recall, I followed the suggestions here and added 1/2" plywood over the 7/8" particle board subfloor that was in the building when bought (yes, I checked the load bearing calculations for the spacing of the 2x10's and steel beams under the floor). I used Versabond over a plywood subfloor, mixed thin per instructions to set the Ditra on top. I looked all over for a dryset as "required" by Schluter, with no joy. I went back and bought Versabond gray to use over the Ditra, knowing it would void my warranty, but others had good luck with it. The floor sat for over one week between laying and grouting . . . some sat as long as 3 weeks from laying to grout time.

Here I am two years later, and there is not a single crack or problem with the floor. This was my first sizable tile job, and you guys gave me the knowledge and comfort level to do it! 1000 square foot of slate flooring, and a lot of mortar mixing (my craftsman drill is still working!) and elbow grease, and this floor still looks like a million bucks!

Total materials cost: about $4,000 (tile price was $1.25 per square foot at the time, the rest was mud, Ditra, plywood, screws, sealer, and tools. We got the grout on sale for $1 per bag as they were clearing out a gray and a muted green "tea leaf" color that dries to look basically gray).
Total time from laying subfloor to sealing: 7 weekends working 12+ hour days, with one helper about 1/3 of that time. (probably 150 man-hours).
Lesson to be learned: It's doable by almost anyone, but not for the faint of heart.

Thanks again for all the help!

[bbcamp]

Glad to hear your project went well, Homer! Got any pics you want to share?

[Dobri]

Homer, I have to give you credit for doing such an expensive on materials and labor job against the Ditra warranty. I personally would never do anything against manufacturer recommendations!

[H-man1]

Bob, I'll try to take some pics, but no promises on getting them uploaded soon. Dobri, I didn't feel like it was such a risk after reading many of the threads from professional installers that had used the Versabond over the Ditra . . . and my update was to confirm that following their guidance had worked and stood up to two years worth of commercial traffic.

While it is nice to follow mfg. instructions, and that is my standard motto (notice that I did read all documentation, including the warranty, then posted this thread to enquire) it works better when the retailers offer the materials that would allow you to follow the instructions and do a decent job.

If you can't buy a decent dry set locally, how are you supposed to follow those instructions on a tight schedule? If I followed your mantra and never did anything that would void the mfg. warranty, I would have never completed this project in time to meet the deadline.

As with everything, opinions and experiences differ, but I wanted to report back so that this experience with using Versabond over Ditra was completely documented with a follow-up on the long-term result, as I searched a lot of threads before executing on this project. Hopefully this thread will help someone else who is considering a project. If my floor was going to crack due to lack of curing, it would have happenned by now.