# Did Ditra hold moisture in thin set



## Big Dog Dan (Dec 20, 2006)

When I went back to my 500sf/12" over ditra,on concrete, I found corners up and down every two or three tile. (My first time with ditra so I think it is totally my fault)

I am wondering if the ditra retained the water in my thin set too long.

I always used a slightly wet mix, but not so as to not trowel. When I put the tile in, they were level, but now the corners are up and down. However is it possible that because I used this mix,that it did not dry out as fast as it should on top of the ditra and the tile setteled slightly? 

I took up a few tile and reset them, but I am not able to get the corners matched. 
Any suggestions or ways to fix it? I also had some small up and downs on the concrete, 
I am thinking I have to remove it all and start over, but this is not what I want to do. 
Also if I put down a layer of backer over the tile, can I re-tile over the tile?
I have room for the extra height,at doors ect. 


How can I remove and realign the corners?


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## Floormasta78 (Apr 6, 2011)

you didn't mix your thinset right, that should never happen . another reason was the wrong trowel was used. I don't see an easy repair other than to replace everything..


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## Big Dog Dan (Dec 20, 2006)

Floormasta78 said:


> you didn't mix your thinset right, that should never happen . another reason was the wrong trowel was used. I don't see an easy repair other than to replace everything..


 Think you are right. 
When I mix my thinset, it aways worked for me. 
I think I will go test my mix on a new area to see.


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## Floormasta78 (Apr 6, 2011)

What was the size of the tile ? 
Porcelain, or Stone ?. Marble is a very heavy stone you need a non sag thin set


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## Big Dog Dan (Dec 20, 2006)

It is 12" Porcelain
I have never set marble.
Maybe that is the problem. The thinset was unmodified as ditra requires, Maybe I should of used no sag.


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## HS345 (Jan 20, 2008)

Big Dog Dan said:


> Also if I put down a layer of backer over the tile, can I re-tile over the tile?
> I have room for the extra height,at doors ect.


How exactly would you accomplish this?




Big Dog Dan said:


> It is 12" Porcelain
> I have never set marble.
> Maybe that is the problem. The thinset was unmodified as ditra requires, Maybe I should of used no sag.


Sounds like you mixed your thinset too loose. You shouldn't need a medium bed to set 12x12 porcelain.

What type of unmodified thinset did you use. 

Are you a pro?


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## Floormasta78 (Apr 6, 2011)

Go easy on him.  .. lol


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## Big Dog Dan (Dec 20, 2006)

HS345 said:


> How exactly would you accomplish this?
> 
> 
> 
> ...


How exactly would you accomplish this? not to easy. 
I used Mega Bond unmodified
Not a pro, but have satisfied clients that recommend my services


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## HS345 (Jan 20, 2008)

Big Dog Dan said:


> How exactly would you accomplish this? not to easy.
> I used Mega Bond unmodified
> Not a pro, but have satisfied clients that recommend my services


Megabond wouldn't be my first choice, but it should work fine if used correctly.

Not a problem, the fact that you are trying to learn by coming here is a great sign. Live and learn. Best of luck to you.

BTW, there would be no way to properly install CBU over an existing concrete/Ditra/tile installation.


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## HS345 (Jan 20, 2008)

Floormasta78 said:


> Go easy on him.  .. lol


How'd I do? :laughing:


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## Floormasta78 (Apr 6, 2011)

Perfect.. Lol ! 
You gutta re do it.. Welcome to live and learn. And to the professional world of paying for mistakes..


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## Big Dog Dan (Dec 20, 2006)

HS345 said:


> Megabond wouldn't be my first choice, but it should work fine if used correctly.
> 
> Not a problem, the fact that you are trying to learn by coming here is a great sign. Live and learn. Best of luck to you.
> 
> BTW, there would be no way to properly install CBU over an existing concrete/Ditra/tile installation.


I have used it many times without problems.
Do you have a better product you could suggest?
Thanks


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## HS345 (Jan 20, 2008)

Big Dog Dan said:


> I have used it many times without problems.
> Do you have a better product you could suggest?
> Thanks


While I am a big fan of Laticrete products, I am not too fond of their Lowe's proprietary line. I would use Laticrete 317 before I would use Megabond.

My first choice for Ditra over concrete (or anything else for that matter) would be Ardex FB-9L. You won't get a warranty from Schluter, but Ardex will give you a ten year written warranty for that installation if you ask them for it.


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## Big Dog Dan (Dec 20, 2006)

Floormasta78 said:


> Perfect.. Lol !
> You gutta re do it.. Welcome to live and learn. And to the professional world of paying for mistakes..


also I used a 3/8 notch and maybe 1/2 would of been the way to go.

Yep 
I love learning something new, and this one is giving me knowledge I didn't want to know so much about. 
Thanks


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## Big Dog Dan (Dec 20, 2006)

HS345 said:


> While I am a big fan of Laticrete products, I am not too fond of their Lowe's proprietary line. I would use Laticrete 317 before I would use Megabond.
> 
> My first choice for Ditra over concrete (or anything else for that matter) would be Ardex FB-9L. You won't get a warranty from Schluter, but Ardex will give you a ten year written warranty for that installation if you ask them for it.


Sounds like what I will use next time
Do you know if Schluter has their own product that they guarantee?


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## HS345 (Jan 20, 2008)

Big Dog Dan said:


> Sounds like what I will use next time
> Do you know if Schluter has their own product that they guarantee?


Schluter doesn't have a product of their own, but Bostik makes a product called Ditraset, which is a very good unmodified thinset. Custom also has a high quality unmodified out called Uncoupling Mat Mortar. Mapei's Kerabond is also very good. Don't confuse Keraset with Kerabond.

Ditraset (scroll down, can't link directly)

UNCOUPLING MAT MORTAR

Kerabond


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## Floormasta78 (Apr 6, 2011)

Me , I use 253R in small jobs, and regular 253 from Laticrete. No warranty because it's modified ( maybe not the best advise, considering you have to do "everything by the book " )
But I have installed thousands of square feet of Ditra, and no fails. Only one, but it was a small 6x6 bathroom and it failed because, I USED UNMODIFIED..


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## Floormasta78 (Apr 6, 2011)

See, ..


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## Big Dog Dan (Dec 20, 2006)

so yours failed by using unmodified?
why do they say not to use it?
please advise


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## HS345 (Jan 20, 2008)

Floormasta78 said:


> Me , I use 253R in small jobs, and regular 253 from Laticrete. No warranty because it's modified ( maybe not the best advise, considering you have to do "everything by the book " )
> But I have installed thousands of square feet of Ditra, and no fails. Only one, but it was a small 6x6 bathroom and it failed because, I USED UNMODIFIED..


How do you know it failed because you used unmodified? Did Schluter cover the failure under warranty?


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## Floormasta78 (Apr 6, 2011)

the job was too smal to call and complain. i just did it over, in fact the tiles came up clean. i had enough Ditra to cover the 6x6 batnroom. Unmodified does not have enough '' Grab " .


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## The Coastal Craftsman (Jun 29, 2009)

Floormasta78 said:


> the job was too smal to call and complain. i just did it over, in fact the tiles came up clean. i had enough Ditra to cover the 6x6 batnroom. Unmodified does not have enough '' Grab " .


I have always used modified with ditra and kerdi and never had issues either. Only reason I carry on using it is because I have always used modified on these type of systems for over 10 years and it's always worked. Hate to try something different then it fails.


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## Floormasta78 (Apr 6, 2011)

Yea !! See what I mean. every so often manufacturer recommendations are lame ! and don't work


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## HS345 (Jan 20, 2008)

Floormasta78 said:


> Yea !! See what I mean. every so often manufacturer recommendations are lame ! and don't work


I've used modified and unmodified with Kerdi and Ditra, never had a problem with either. I have also done the experiment where you stick two pieces of porcelain together with .unmodified.....works every time.


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## Big Dog Dan (Dec 20, 2006)

Floormasta78 said:


> Yea !! See what I mean. every so often manufacturer recommendations are lame ! and don't work


Do your clients agree with you and tell you to forget about the warrentee?


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## Floormasta78 (Apr 6, 2011)

No. that's something that no one in their right mind would say to Customer. My warrant is my reputation, therefore I will never compromise my work by doing something that I KNOW WILL NOT WORK.. It's part of knowing what you are doing. Did you tell your costumer that it's your first time working with Ditra and that he should pay you ,for you to learn on his job.. I doubt it.


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## Big Dog Dan (Dec 20, 2006)

I do understand when you are good at something, you know from experience what you can do.

To my surprise he offered to pay half on the repair, but I told him that was totally out of line. He trusts me just like your people do.


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## Floormasta78 (Apr 6, 2011)

Everyone makes mistakes. I've made some that end up costing me thousands. But when we admit them and take care of them , we are the better half still..


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## Aaron Tritt (Feb 4, 2011)

Big dog,

There is no reason to use a non modified thinset with Ditra or any other uncoupling membrane.

The concern comes with the additives in a modified that increase cure time. In CBU/ply install situations these additives allow the crystals to grow and a high bond/compression strength to occur. 

It is best if you can wait to grout the tile for several days so the thinset can cure with a modified/ditra situation. Sometimes this is not practical and I will use a grout that ensures color consitency regardless of cure time/moisture content/grout joint sizes.

I have never had a problem with Ditra, but prefer SpiderWeb because it is a little less costly, and there is a 10 year warranty from custom with modified thinset.


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## Big Dog Dan (Dec 20, 2006)

Aaron Tritt
I check out the spider web and it looks just as good and maybe a little more flexible 
thanks for the tip.

http://http://www.indianafloorsllc.com/Spiderweb_Customunderlayment.aspx


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## bluebird5 (Dec 13, 2010)

Orlando, you are saying you set your ditra to the plywood or slab with 253R and then set your tiles to the ditra with 253? Lets say you finish setting at 5:00 one evening, how long will you wait to grout? In theory 252 should dry faster that 253 because it has less pollimers (however you spell it) is that safe to say? Would you only recommend setting the tiles with a rapid set because it can dry without air?


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## Floormasta78 (Apr 6, 2011)

Grouting, is very easy. I use regular 253 to set Ditra and to install tile. the only times I use 253R is in a small job. No more than 100 sft. 

Regarding spider Web, its a real good product, much easier to use when troweling thinset and setting tile. Its smoother.


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## Big Dog Dan (Dec 20, 2006)

Floormasta

what do you use to set spider Web?
253?

anyone know what is going on with the forum
one post is under my name below this one, and I can still edit 
24 hrs later on this one!?


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## Big Dog Dan (Dec 20, 2006)

Not my post



Aaron Tritt said:


> Big dog
> 
> The concern comes with the additives in a modified that increase cure time. In CBU/ply install situations these additives allow the crystals to grow and a high bond/compression strength to occur.
> I am sorry what is cbuply?


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## Anderson (Sep 7, 2009)

Big Dog,Go do the Schluter class and all questions will be answered. They have engineered the hell out of these products and you should follow there recommendations.


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## Floormasta78 (Apr 6, 2011)

Same thin set .. 253 Gold.. As you can see from the pictures I have a fetish for Laticrete and 253 Gold . 
I don't use anything below that, only higher in the laticrete product line.


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## Floormasta78 (Apr 6, 2011)

Not true Anderson. You follow what works for you. Yea you will learn the BASICS but in the real world every application is different.


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## Aaron Tritt (Feb 4, 2011)

CBU is cement board underlayment (durock,wonderboard,etc)
Ply is plywood


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## TheItalian204 (Jun 1, 2011)

Used three particular thinsets to install on ditra.

Polymer modified Versabond 22.99$ a bag (exceeds specification 118.4,118.11 if I remember bag properly),Mapei Kerabond and Mapei Ultraflex LFT2...been very happy,never failed,been mixing them up depending on size of job and quote.


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## Winchester (Jun 29, 2008)

I've always used kerabond for that and never had a problem


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