Another Ditra Discussion

[cx]

Originally Posted by FP

Make sure he uses a uncoupling membrane. If the house moves the tiles won't crack.

FP, you'll need to come up with some justification for that claim. There is no ceramic tile industry standard for such "uncoupling" membranes at all. They're required to stick to the floor. Nothing else. They may or may not be as good as or better than a CBU for protecting the tile installation "if the house moves," eh?

[traderfjp]

Took this off the Schluter site. Are you saying this is BS: Schluter®-DITRA membranes provide uncoupling through free space, which allows for in-plane movement that effectively neutralizes the differential movement stresses between the substrate and the tile, thus eliminating the major cause of cracking and delaminating of the tiled surface.

Looking at the tiles. The discoloration is not haze. I can see some haze but try the solution for kicks. Let us know how you make out.

[ss3964spd]

FP, while Schluter does make that claim, what I have read here is that there is no tile industry independent test available to prove, or disprove, that claim.

Keep in mind, too, that Schluter specifically states "in-plane" movement. Think of a concrete slab with a hairline crack in it, but the surface on either side of the crack is not higher than the other. If that crack only widens Schluter says Ditra can absorb that in-plane movement (to some degree). But if one side rises above the other it, presumably, can't absorb that out of plane movement.

Schluter's products are highly regarded everywhere, including here, and I'm inclined to believe their claim. But without independent, standardized testing there's no way to prove it.

[traderfjp]

I've seen a lot of cracked tile over the years and there are many reasons why. I understand what you are saying and while Ditra isn't perfect in every situation - it may be better than nothing at all. It does raise the floor height which could be problematic.

[jeffnc]

>while Schluter does make that claim, what I have read here is that there is no >tile industry independent test available to prove, or disprove, that claim

It's intuitively obvious. In any case there are many versions of crack isolation membranes and uncoupling membranes that are all accepted to work perfectly fine and are accepted industry standards. No different in concept from adding expansion joints to large expanses of floor tile. This is not controversial, it's just not relevant to this discussion so I'm not sure why the comments are even here other than someone wanted to muddy the waters by showing what they know.

[cx]

Originally Posted by Jeff

It's intuitively obvious. In any case there are many versions of crack isolation membranes and uncoupling membranes that are all accepted to work perfectly fine and are accepted industry standards.

Really a discusssion for the Hangout, but if it were that obvious, Jeff, someone would have figured out how to test the theory. No one has. It's a theory.

And while there is a published method for the use of uncoupling membranes in the TCNA Handbook, that was put in there - entirely incorrectly in my opinion - when there was only a single product available that met the description. Now there are many products claiming to be uncoupling membranes and some of them of very different construction than the original Schluter product. All make the same claims. None have ever been verified. There is no industry standard for "uncoupling" membranes!

There is, on the other hand, an industry standard for crack isolation products (ANSI A118.12), and appropriate and standardized testing therefore. Whole different concept.

My opinion; worth price charged.

[traderfjp]

Interesting. Laticrete sells a mat. I believe it's tested since it has an ansi rating. Meets ANSI A118.12 specifications. Would this provide protection, in your opinion?

[jeffnc]

Originally Posted by cx

It's a theory.

And while there is a published method for the use of uncoupling membranes in the TCNA Handbook, that was put in there - entirely incorrectly in my opinion - when there was only a single product available that met the description. Now there are many products claiming to be uncoupling membranes and some of them of very different construction than the original Schluter product. All make the same claims. None have ever been verified. There is no industry standard for "uncoupling" membranes!

There is, on the other hand, an industry standard for crack isolation products (ANSI A118.12), and appropriate and standardized testing therefore. Whole different concept.

It's not just a theory, it's obvious. I'm not talking talking about ANSI, I'm talking about basic materials science concepts that anyone can understand. Bend, don't break. Same idea as caulking changes in plane or other gaps. If a material can bend or stretch or flex rather than cracking, then that obviously helps avoid cracking. It's not rocket science and it doesn't need to be "verified".

Do you really have to argue every tiny detail? Rather than trying to figure out some way to read a comment and figure out how it's wrong, maybe try to figure out how it may be right. Your constant haranguing gets old.

[cx]

It's not a tiny detail, Jeff, it's a substantial consideration. Ask the members of all the technical committees who have been grappling with it for years.

[jadnashua]

The whole floor on a Ditra installation is characterized by Schluter as emulating a tile installation on a sand bed which has been used for centuries in Europe. The tile (and the thinset holding it to the membrane by a purely mechanical connection that is flexible) can move independently of the material underneath.

As mentioned, it has little to no effect on vertical movement, and the vast majority of the effect is on horizontal movement. The air filled ridges can easily flex. https://youtu.be/z4agCG9QZzA

In the industry, they use the Robison floor test to determine strength and reliability of the tile installation. Their ratings go from light to extra heavy duty. Ditra does well in all of their tests. You can read more here: https://resources.schluter.com/media...20Handbook.pdf

That test does not account for cracks or the subflooring moving, though, only the ability of the assembly to keep the tile bonded without fracturing from the weight applied.

[jeffnc]

Originally Posted by cx

It's not a tiny detail

And once again, you've succeeded in avoiding understanding my point so as to continue submitting yours.

[cx]

Some of these threads are read decades after the fact, Jeff, and it's important to have accurate information in them. Again, this discussion was better suited to the Hangout, but it wants to be accurate there, too.

[jeffnc]

The information I posted was accurate unless you're inflexible in your interpretation. Rather than telling people how wrong they are all the time, if it's important to you then just ask a question to clarify what was meant.

[cx]

OK, Jeff, I've moved our discussion from the Visitor's unrelated project thread to the Hangout where it should have been in the first place and I take full responsibility for having derailed her thread.

Perhaps we'll even get our new Schluter rep to weigh in here with us.

Originally Posted by Jeff

It's not just a theory, it's obvious. I'm not talking talking about ANSI, I'm talking about basic materials science concepts that anyone can understand.

Once was a time when it was pretty obvious that the earth was flat, too.

I've opined for many years here that I think the theory behind the Ditra sounds feasible and I think it probably helps in some fashion. But without any repeatable testing to determine just what it will and will not do, the tile industry cannot establish a standard for such products. Been people, including Schluter I would think, trying to come up with a test for the theory for decades now. No luck.

Originally Posted by FP

Make sure he uses a uncoupling membrane. If the house moves the tiles won't crack.

As for being picky about details, I accept that criticism, but we can't let statements such as the one FP made without at least a bit of explanation. We owe it to our visitors on their DIY projects to provide the best and most accurate information we can.

[jeffnc]

Originally Posted by cx

Once was a time when it was pretty obvious that the earth was flat, too.

Oh brother. I mean honestly, if you can't figure out how caulk and expansion joiints work, nothing I can say will help.