# Ditra Failures??



## jarvis design

Has anyone had any failures (or heard of any) when using Ditra? 
I have encountered 2 people here who had it installed and are having constant problems with grout and tile cracking. Both installations "seem" to fit Schluters criteria, however, since I didn't do the jobs, I have no idea what was used for mortar. 
In talking with a supplier (who doesn't sell Schluter), he says he sees it all the time - when ditra is installed on a single ply subfloor (5/8")

His explanation was that just because houses are "supposed" to have floors meeting deflection requirements, that doesn't mean they do!!

I have been using Kerdi for years - love it, and was starting to use ditra, but certainly don't want problems down the road.

Anyone else heard anything??


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## WarnerConstInc.

Tore some tile up once, they were stuck good to the ditra but, the ditra just pulled right up like carpet padding.


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## PrecisionFloors

The biggest reason for failure is not following directions. The thinset used to install the Dita must be modified and it must be mixed loose enough to ensure good saturation of the fleece. Then the Ditra must be embedded in the thinset with direct pressure. I use a wall paper roller, but a grout float, flat side of a trowel, drywall knife, etc. will work. The key to installing it is getting the fleece properly embedded in the thinset. Outside of that I know of no failures.


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## SLSTech

jarvis design said:


> Has anyone had any failures (or heard of any) when using Ditra?
> 
> ... when ditra is installed on a *single ply subfloor (5/8")*
> 
> ... but certainly don't want problems down the road.


If you don't want problems down the road - no single layer of 5/8 plywood only, I can't think where that would meet any deflection standard 

I could almost guarantee that you would have the same problems with regular backer board.


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## JazMan

I don't see a scenario where Ditra can be blamed for a tile failure. If it doesn't stick to the floor, it's the fault of the installer for using the wrong thinset or not applying it correctly. Another reason would of course be too much deflection in the subfloor or bad prep. Ditra can not cause a problem, it can only prevent them. 

Yes 5/8" plywood single layer subfloor is very scary and I would not recommend going over it unless the joists are at 12" o.c. or less. Manufacturers might tell you 5/8" will work, BUT they also ALWAYS tell you the floor must meet L360 deflection and IRC code. Sometimes this info is not highlighted so not to scare off potential customers.

Jaz


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## JJC

Schluter does say it has to be T&G plywood!!!


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## Bud Cline

DITRA when installed properly is warranted over a 5/8" plywood T&G subfloor. I too am not convinced that's enough subfloor thickness. In a lot of areas the 5/8" subfloor is the minimum building code so I suppose that is why Schluter has chosen to warranty their product over 5/8". The cost of the DITRA along with the need to add additional subfloor thickness would push them out of the market in a lot of cases.

Many builders either build to the absolute minimum to save money or they just simply don't know what to do.

I recently inspected a tile installation over DITRA where the installer was blaming the DITRA for the failure. This case went to court. It was my finding after an invasive inspection that the DITRA had not been properly adhered to the substrate. All other criteria surpassed minimums.

There were areas that the DITRA backing had never been saturated with thinset. The thinset was there but it didn't get absorbed into the DITRA fabric. A 1/4" notched trowel had been used to install the DITRA and of course it was obvious the thinset had been applied too thick. In an effort to spread the thinset under the DITRA mounds of thinset developed creating humps in the DITRA and resulting in tile lippage.

I know of no DITRA failures anywhere.


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## Bill_Vincent

I've been using Ditra now for several years, and I've been coming into the forums (plural) even longer than that, and this is the first I've heard of a failure over Ditra. You'd have to really convince me that it was the fault of the Ditra.


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## MattCoops

I've yet to tear out any tile installations from the 60s - 70s that had Ditra, or any other Schluter products. So I'm not so certain on the validity of their warranty. I do believe their company to be the "scientists" of the tile industry, and they offer quality products.
I've always liked their metal profiles and transitions. And the fact you can purchase their products at The Home Depot and Lowes, makes it very convienent for do-it-yourselfers to use in their projects.
I just wish more of my customers liked metal in their residential tile applications. Most of the homes we work on we just use traditional tile details like bullnose and miter cuts. They don't even want metal around their showers' glass enclosures, never mind touching their tile.


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## Cache

I would never feel comfortable laying tile over a 5/8" subfloor. Even if joists are 12"o.c. a 5/8" sub is really springy. At least 3/4"T&G for ceramic at 16oc joists. 3/4"T&G laid perpendicular to joists followed by additional 1/2" ply for natural stone. 

OTOH, I've walked on ceramic floors with noticeable deflection as I walked across them, and no problems after using ditra.


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## Jerry T

I visit alot of forums too, and on one venue the poster had installed the DITRA upside down......... I still can't figure out how someone could be dumb enough to do something like that.


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## reveivl

Jerry T said:


> I visit alot of forums too, and on one venue the poster had installed the DITRA upside down......... I still can't figure out how someone could be dumb enough to do something like that.


Yes, but did it work?:jester:


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## jarvis design

I would like to thank you all for the replies. I tend to agree with the notion that a lot of problems are caused by poor installation or, as mentioned, floors that barely meet deflection minimums. 
Unfortunately, that seems to be a trend!! 
I have seen some really well laid floors (in terms of layout, flatness, etc) that failed because of brutal preparation work.

I have used 1/2" concrete board - set in thinset and screwed, for many years with no failures - however, let me just say, 95% of my work is bathrooms. I like the features of Ditra but will be more aware to look at the existing substrate. 

A couple of jobs where I did use ditra, the subfloor was OSB so I installed 3/8 plywood over, then ditra. I am thinking this may be the way to do all floors, even 5/8" ply. Any thoughts??

P.S, - Bud mentioned about too much/too little thinset under the ditra - I have used both the Ditra and Kerdi trowels from Schluter - and find them both excellent - perfect coverage and they are really nice trowels (made by Rubi)


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## R&D Tile

I will never use a cbu on a floor again, unless a very small area or where I need the height in a small area.

Ditra is all I'll use.

The only thing about all of this is getting a FLAT and LEVEL floor, if it isn't, I'll mud it, still the best method.


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## PrecisionFloors

R&D Tile said:


> I will never use a cbu on a floor again, unless a very small area *or where I need the height* in a small area.
> 
> Ditra is all I'll use.
> 
> The only thing about all of this is getting a FLAT and LEVEL floor, if it isn't, I'll mud it, still the best method.


Schluter has that covered too! Check out the Ditra XL. You can also double layer Ditra if you want to, but that would be too expensive unless it was a powder room or something.


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## jarvis design

MattCoops said:


> I've yet to tear out any tile installations from the 60s - 70s that had Ditra, or any other Schluter products. So I'm not so certain on the validity of their warranty. I do believe their company to be the "scientists" of the tile industry, and they offer quality products.
> I've always liked their metal profiles and transitions. And the fact you can purchase their products at The Home Depot and Lowes, makes it very convienent for do-it-yourselfers to use in their projects.
> I just wish more of my customers liked metal in their residential tile applications. Most of the homes we work on we just use traditional tile details like bullnose and miter cuts. They don't even want metal around their showers' glass enclosures, never mind touching their tile.


Hi Matt, I too like using metal profiles (especially Schluter Rondec and Quadec). It used to be the majority of tiles had matching bullnose trims, but, they seem to be eliminating these trim profiles. I think you get a cleaner edge vs. bullnose trim - especially when painting up to it.


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## MattCoops

I know the brass selection of Rondec series edge profiles are delightful and enduring.
Again, for the Ditra, I've yet to meet a tile setter that has demolished any tile installations prior 90s that had the plastic orange underlayment underneath their ceramic/stone. Therefore, I don't know the actual duration of the material. For all I know, the 2020 T&A publications may even recommend NOT using it. Heck, take the coveted "green board" recommendations by the TCNA for instance in bathroom wall installations. One year it's ok, a few years later it's nixed?


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## Bill_Vincent

> For all I know, the 2020 *T&A publications* may even recommend NOT using it.


Uh..... Matt.... which website did you think you were on? :innocent:


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## Bud Cline

Not following any of this anymore.


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## jarvis design

My apologies, this thread did kinda go sideways

Let me say I am very happy to see that the "supposed" failures I have heard about are a result of (what I suspected) bad installs and I think, some false rumors started by people who don't sell Schluter!!


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## MattCoops

What don't you understand? I'll clarify it for you.


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## rsss396375

PrecisionFloors said:


> The biggest reason for failure is not following directions. The thinset used to install the Dita must be modified and it must be mixed loose enough to ensure good saturation of the fleece.
> 
> Good call
> This is the biggest issue for good adhesion. Mix almost a watery consistancy, not as though you are used to when setting. You should be able to see a grayish color consistant through the Ditra orange.


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## reveivl

> ...the 2020 T&A publications...


I guess you'd want 20/20 if you had publications like this to look at...:jester:


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## Jerry T

reveivl said:


> Yes, but did it work?:jester:


 It's been a few years ago, but that poster left me scratching my head ....... you have to go way out of your way to put Ditra in upside down.


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## rfrymier

Has anyone applied ditra for exterior use beneath stone tile on stairway from house to patio?


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## Bud Cline

> Has anyone applied ditra for exterior use beneath stone tile on stairway from house to patio?


Why would anyone want to?


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## buildenterprise

According to Schluter you're supposed to use UN-modified mortar to install the Ditra.



PrecisionFloors said:


> The biggest reason for failure is not following directions. *The thinset used to install the Ditra must be modified* and it must be mixed loose enough to ensure good saturation of the fleece. Then the Ditra must be embedded in the thinset with direct pressure. I use a wall paper roller, but a grout float, flat side of a trowel, drywall knife, etc. will work. The key to installing it is getting the fleece properly embedded in the thinset. Outside of that I know of no failures.


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## Bill_Vincent

Over concrete, it's either/ or. The MUST use unmodified is for installing the tile over the Ditra.


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## angus242

I'm not going to question each person's views on how they install Ditra.
However, the Ditra Installation Handbook says:
Ditra installed over wood, use modified.
Ditra installed over cement, use unmodified.
Always unmodified to set tile over Ditra.


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## PrecisionFloors

buildenterprise said:


> According to Schluter you're supposed to use UN-modified mortar to install the Ditra.


Actually you're supposed to use thinset suitable for the substrate you're setting on, which in the context of the first post of this thread, is a wood sub-floor, which would require a latex modified mortar 

:thumbsup:

edit: Damn...didn't even see The Colonel's post. What he said.


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## jarvis design

rfrymier said:


> Has anyone applied ditra for exterior use beneath stone tile on stairway from house to patio?


I did my front step/walkway with ditra. Installed 12x24 porcelain on top with epoxy grout.

I haven't given it a good cleaning yet from the winter, but, it looks exactly like it did when I did it last fall.


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## MF Custom

PrecisionFloors said:


> The biggest reason for failure is not following directions. The thinset used to install the Dita must be modified and it must be mixed loose enough to ensure good saturation of the fleece. Then the Ditra must be embedded in the thinset with direct pressure. I use a wall paper roller, but a grout float, flat side of a trowel, drywall knife, etc. will work. The key to installing it is getting the fleece properly embedded in the thinset. Outside of that I know of no failures.


Better check into using modified thinset with Ditra, It say right on the instructions in BOLD "USE ONLY NON MODIFIED THINSET"


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## PrecisionFloors

MF Custom said:


> Better check into using modified thinset with Ditra, It say right on the instructions in BOLD "USE ONLY NON MODIFIED THINSET"


Have you read the WHOLE post.....something tells me not. Scroll up. It's right there for your very own eyes to see


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## R&D Tile

MF Custom said:


> Better check into using modified thinset with Ditra, It say right on the instructions in BOLD "USE ONLY NON MODIFIED THINSET"


For setting tile only, you need modified for installing Ditra over plywood.


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## Bill_Vincent

MF Custom-- Nobody's perfect-- not even me!


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## Jerry T

Bill_Vincent said:


> MF Custom-- Nobody's perfect-- not even me!


 Me neither Bill :no: :laughing:


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## MF Custom

I just posted what Ditras instructions say right on the label.
"USE NON MODIFIED THINSET ONLY" but I would think over plywood you are correct it should be modified thinset.


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## angus242

MF Custom said:


> I just posted what Ditras instructions say right on the label.
> "USE NON MODIFIED THINSET ONLY" but I would think over plywood you are correct it should be modified thinset.


Actually *I *posted what's on the instructions...even with pictures:
http://www.contractortalk.com/f73/ditra-failures-51079/index2/#post668041


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## JohnFRWhipple

*Exterior decks and Ditra Failure (Canadian Installations)*

Have you men read this thread on John Bridges site? 

http://www.johnbridge.com/vbulletin/showthread.php?t=83568

I have not been able to shake this new training I received at Mapei and the story of the Whistler Builder who ripped out all the Ditra from his exterior deck because he "Hates" it and does not think it is suited for exterior use in our Canadian Climate.

Only one poster touched on what I think the root problem can be and that is the little dovetails holding water and the freeze thaw cycles expanding and pulling on the Kerdi Seams.

You will notice as well that the Ditra is layed across the slope creating little dams so the water will be held up every 3 feet...

My deck is still getting soaked. I Hydro Banned it till Spring time and think I'm going to try Nobel Deck as my Primary waterproofing material...

Now to get it approved for use in Canada.


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## angus242

John,

There were many installer issues with that deck. In that climate, that install was bound to fail.


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