Hello,

I'm new here and am in need of some serious help, and I hope I'm posting in the correct place. Ill start this of by saying I'm not a professional at the work I’m doing on my home but I have been told my work is very good, and not by my mother, questionable but good or works. I am in the military up here in Alaska, I bought a home 2 years ago and have been doing upgrades to it. I am having trouble with the kitchen floor, here's where it gets all jacked up.

The sub floor is plywood with a 16” on center joists give or take a little, its also over a crawl space, warm and dry under the house. What I had to do to get this floor level is another story. I put durock over it with thin-set screwed in and taped the joints, some are not taped now.

Then I bought Ditra-XL/175 and tried to install it last week and had to take it back out the next day, It did not stick at all It came up way to easy. I think the thin set (unmodified) was old, as it had been in the garage for a year, so it may have had moisture in it. When it dried I could break it like a cookie, and smash it into powder. I did the lift the corner test on the Ditra and had very good coverage, I used the float to push the Ditra into the thins set. The thin set was moist and a little thinner then peanut putter but able to leave the troul marks. I spent the next few days cleaning the dried up thin-set off the Ditra, it looks like new Ditra again so it cleaned up well and easy, telling me even more that the thin set failed ( I think?).

So round two I got new Thin-set from Home depot, around 7 dollars a bag so I need feed back on this thin-set too that sounds too cheap to me? Name brand of thin set is LATICRETE / Floor adhesive economy grade and it meets ANSI A118.1. So before I go through all that hell again I want to make sure its going to work, so I took a small piece of Ditra and mixed a small amount of the new Thin-set and put in on the floor. Again the same thing happened almost 24 hours later It pulled up like it had nothing holding onto it? I have watched and read many forums and videos and so on on how to install and am a fan of Mike Holmes T.V show. I know this post is as long as a book but I am pulling my hair out and the kitchen needs to get done soon, as its been in shambles for over a year.

Please help.. Im going to try and post pics...

Michael J.

Hi Michael,

First of all......thanks for your service.

Several things......

1st. There was no need to install Durock since you're going premium with Ditra. But OK.

2nd. Although all unmodified thin sets out there meet A118.1, some are just too cheap to trust. Schluter wants you to use a "premium" thin set. $7 a bag is not premium. Also make sure you mix it a little runny, probably thinner than you did. You also need to dampen the Durock so it doesn't suck as much water from the thin set. What type/size trowel did you use?

Thin set and most Portland products, have a shelf life of about 12 months from date of manufacturing IF un opened and kept in a conditioned space.



How did you determine it came up too easy? If you pulled on a corner, that's wrong. That method applies many x's the stress it'll ever see in real life use. Don't do that!

What other type/brands of thin set can you find there? Laticrete is a world-class company, but the good stuff isn't $7.

Jaz

Thanks for the post Jaz,

I used a 1/4 Square Trowel. Im going to return the thinset back to home depot and buy Modified from them Im sure the Modified from them is ok its around 27$ a bag. Im going to use this thinset to set the Ditra in and then set the tile in and be done with it....
I hope.

And the Durock was a mess up ive been told that a few times now and the thing is I knew better, I dont know what I was thinking at the time..

I see you posted at JB's too. You'll get lots of good answers there too.

1/4x1/4 square notch trowel is kinda too much, but will still work. Hold it at a low angle. On the other hand, that trowel may be too small for the tiles. I don't recall you mentioned much about the tiles.

On the thin set, if your selection is poor, go ahead with an economical modified then. Not sure which one your HD carries there. You do not have to spend $27 a bad when Ditra is involved. Should be under $15, even in AK. Schluter will not back you if you use modified, in case you cared about a warranty. I don't.

Jaz

here I go again, LOL...

I have listened to all and appreciate all the response. I once again put down a small piece of Ditra for a test, and have let it sit for over 48 hours and pulled it up with ease, when I say pulled I mean with no resistance. I know if I had laid tile in that amount of time I would have had a hard time getting it up.

I know once its down it wont have that kind of wear and tear as far as someone pulling up on the product, but over time with that kind of stick I would think it would work it self up with traffic pushing down? When I inspected the piece of Ditra on the cloth side it had residue of the thin-set then I pulled the cloth away on part of it to see if it pushed thru the cloth, it did not, it look the the other side of the Ditra nice and clean.

Again I did read what you all told me about don’t pull and stop pulling but I had a second test running. Now maybe I’m not tracking how this stuff works put I thought that the thin-set had to make its way thru the cloth and fill in the waffle like surface to a point, am I wrong on this? Is the thing set just supposed to grab a hold of the cloth?

And again, at no way am I questioning any one of your knowledge on this product or your field of work, just don't want to mess this up and want to make sure I’m doing the correct procedure as to putting the Ditra down. I have way to much time and money into this kitchen and I have plenty of time on my side just not the money. I'm going to try and post pics of this kitchen and also a small bathroom I did for your opinions.

ok here are a few pics...

the floor...



new cabinet I put in, sorry about the mess...



the ditra I had to clean..



the fridge will fill that space one day ...




the small bathroom I did ..



the roof of shower..



trim in the shower..

Here is the Test sample of Detra..






A close up, I hope you all can see my consern I'm having,If you look at it close it looks just dirty, and no thinset went thru the cloth.

I'm wondering if the thinset may have skinned over before the Ditra went down. Some parts look like you had good contact, some don't.

Schluter recommends that you dampen the subfloor with a sponge immediately before apply thinset. This keeps the moisture from being drawn out of the thinset before it's covered. Also, keep your thinset a little on the loose side to keep it from drying too soon.

I use a wood float and go over every square inch of the floor with some good pressure to make sure the fleece is fully engaged. Thinset does not need to work it's way through the fleece into the waffles, that's not how it's not designed to work.

From the pics I think you are not applying enough thin set on the floor before you spread it with the trowel. Even though your trowel's notches are too large, there isn't enough material to get an even amount.

As Kevin said the thin set is NOT supposed to go thru and fill the back of Ditra. If that happened, Ditra could not do it's thing which is to move horizontally <--> to relieve the stresses in the floor system, and you'd have a failure.

I can't clearly see the edges of those tiles installed in #1, (is that what I'm seeing there?), but it doesn't look like you used enough thin set under the tiles. (are those tiles?). Which trowel did you use? Did you first spread the thin set with the flat side of the trowel? Then applied more and notched it with the proper notched trowel? Do you remember me telling you I thought 1/4x1/4 was too small for the tiles?

Jaz

Kman thanks for your response,

It could have skinned over, but I don't think so, I mixed it loose and only spreed the thin set the width and length of the area I needed, the longest was 13ft by the width of the Ditra 40''. I did not wet the Durock, how ever I did use a grout float to push the Ditra into the thinset and a ¼ by ¼ by ¼ square trowel to spreed the thin set on. I did the check to see if I had good coverage and it was good.

Jaz thank you for your response also,

In pic #1 Jaz that tile is not set in any thing, it was just there to see how high the floor would be. Also you asked what trowel I used, It was a ¼ by ¼ by ¼ square trowel that I used to put the Ditra down not the tile, as I'm not at that point yet, wish I was. So this is my plan with the help and tips from all of you + I did call the Ditra people to pic thier minds too.

Step #1 - With the new water bottle I just bought from HD will wet the Durock

Step #2 - With the new proper Trowel (¼ by 3/16 V Notched) I just bought from HD I will first spread the thinset with the flat side of the trowel like Jaz stated, then apply more thinset with the V Notched side of the trowel.

Step #2 ½ - This is a maybe, upon your opinions, I was thinking of using that spray bottle to lightly spray the cloth side of the Ditra to moisten it, not dripping wet, but just enough to get it damp. I do live in Alaska and it is dry in the house. Just a thought.

Step #3 - Lay down the ditra and use the Grout Float to press the Ditra in to the thinset.

Step #4 - Pull a corner up and check for thinset coverage. Set it back in the thin set let it dry for more than 24 hours.

Step #5 – PRAY.

I would skip step 2 1/2. The moisture might interfere with the bond. The fleece will not draw excessive moisture out of the thinset, so adding moisture would be of no benefit.

If the Durock is dry when thinset is applied, then it will immediately start drawing out the moisture. Then you have the natural drying action from the top side. Hopefully you don't have any air movement that will accelerate the drying.

Another step I would take, considering the length of the run (13') is to do 1/2 the run at a time. Lay the Ditra out the full length, then roll it up halfway, dampen the floor, and apply the thinset. Unroll the ditra, push it down to engage the fleece, then repeat for the other half. If you look at Schluter's website, they have a video that demonstrates this process.
http://www.schluter.com/7214.htm

The first section he lays out is done all at once, but the second one is done in two sections as I described above.

Thanks again Kman,

Yes I seen that video. ok Im going to skip Step#2 1/2 lol and I thought I was on to something. One thing I see in that Video that makes me think of yet another Question .. How soon after I set the Ditra down can I start laying tile? In the Vid he did it after he was down setting the Ditra, but would think thats not a good Idea, am I wrong again?

You can set tile immediately, however, the only potential problem is if you have to pull up a freshly set tile to level it, or for whatever reason, it's likely that you'll pull the Ditra off the floor in the process. The way around that is to slide the tile horizontally a few inches to break the suction created by the thinset, then lift the tile. If you're pulling up a tile that already has tile set around it, that can be more difficult.

Unless it's a very small room, like a bathroom or entry, I prefer to let it set overnight. Your call, though.

Step #5 can't hurt!.

I do NOT recommend the 1/4x3/16" V trowel, too small. Long story short......I never thought that was enough. After the first job I made the groves large and all was good. After a few years Schluter decided oh yea...you can also use a 5/16" V. What? That's a big diff.

A few years ago they came out with a Ditra trowel which is 11/64" square. (confused yet?) That's about 3/16" square. In the end even the one you just bought may work ok, depends on how you mixed the thin set and the angle you hold the trowel.

Go ahead and sponge or mist the Durock, leave the Ditra alone. If you do all those things you're wasting too much time. And OH.........use a wooden float, NOT a grout float. Rubber doesn't slide so good.

Jaz

Question? what size spacers should be used with the tile I'm going to use, the sises are 12x12 - 6x12 and 6x6 I was thinking 1/4 spacers but not sure if there is a recommended size that should be used or is it on preference...


thanks again...

1/4 is pretty big for the 3 sizes your using.
1/8 to 3/16 may look better. Really depends on what the edges of the tile look like. IE: chiselled, slightly rounded, square etc.

You may also be limited depending on the variations in tile sizes. I would dry-lay some on the floor and see how they work out. You don't want to find out after 1/3 of the job is done that you can't keep a straight line because the tiles vary too much.

I don't think you have a choice how wide the joints are gonna be. Two 6" tiles have to equal one 12". No choice with most patterns I can think of.

Jaz