Ditra Failures??

jarvis design · Jan 10, 2009

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??

WarnerConstInc. · Jan 10, 2009

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

PrecisionFloors · Jan 10, 2009

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.

SLSTech · Jan 10, 2009

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.

JazMan · Jan 11, 2009

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

JJC · Jan 11, 2009

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

Bud Cline · Jan 11, 2009

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.

Bill_Vincent · Jan 12, 2009

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.

MattCoops · Jan 12, 2009

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.

Cache · Jan 12, 2009

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.

Jerry T · Jan 12, 2009

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.

reveivl · Jan 12, 2009

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:

jarvis design · Jan 13, 2009

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)

R&D Tile · Jan 16, 2009

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.

PrecisionFloors · Jan 16, 2009

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.

jarvis design · Jan 17, 2009

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.

MattCoops · Jan 18, 2009

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?

Bill_Vincent · Jan 18, 2009

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:

Bud Cline · Jan 18, 2009

Not following any of this anymore.

jarvis design · Jan 18, 2009

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!!

Ditra Failures??

jarvis design

WarnerConstInc.

PrecisionFloors

SLSTech

JazMan

JJC

Bud Cline

Bill_Vincent

MattCoops

Cache

Jerry T

reveivl

jarvis design

R&D Tile

PrecisionFloors

jarvis design

MattCoops

Bill_Vincent

Bud Cline

jarvis design

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