# ceramic tile laid over composite flooring



## Rotten Apple (Oct 21, 2012)

[ Hi.
My problem is , I have 900 sq. ft. of ceramic tile to install . the floor I'm putting it on is a slab with composite 12 x 12 EXTREMELY well adhered. There is not one loose tile in the house. My question is can I use Ditra right over the composite and then quickset and tile? If so, what should I use to adhere the Ditra? Should I do any particular prep on the composite? The floor is level and smooth. This is in west Texas where there isn't much in the way of freezing. Any input would be really appreciated.
Thanks, Rotten Apple


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## tileman2000 (Feb 14, 2011)

It's not recommended to tile directly over vinyl tile. Easiest way of getting them up is by using a heat gun and a putty knife.

I would remove the vinyl and use a modified thin-set to set the new tile.


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## TNTRenovate (Aug 19, 2010)

Do it right. Remove the old floor, prep the substrate, install the new floor per manufacturers instructions and best practices as recommended by the TNCA.

That is all...


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## fcfc (Mar 10, 2012)

Tiling over vinyl be it sheet or modular can be done provided certain conditions are met. First, there only be one layer of vinyl. Second, that it be well adhered. Third that the floor still meet the appropriate deflection criteria for the install you are attempting. Also it cannot be any type of 'cushioned' vinyl.

If you check out this link http://www.schluter.com/media/DitraHandbookENG-2012.pdf it will lead you to schluters installation guidline which includes techniques and criteria for installation over existing vinyl substrates. 

It comes down to stability and structure. If you have those, you could probably install tile over looselayed felt paper and have it last. (whistle)

Before I get flamed, I have personally installed my display floors that way in my store, I move several hundred pound displays over then seasonally, and have yet to have a cracked grout joint in the past 5 years.


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## TNTRenovate (Aug 19, 2010)

But why risk it? Your showroom is different from a customers home or even your own home. Again, I say why risk it? Why put something in play that may effect the installation down the road?


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## fcfc (Mar 10, 2012)

What affects an installation for tile comes down to degrees of risk. Any tile job can fail for any number of reasons. Circumstances beyond the control of the installer or homeowner can lead to issues outside of the scope of the original work. Failure in HVAC, flooding, roof blows off, the end of the world mayan prophecy coming into play. 

TCNA has developed its best practices from field experience and its guidelines (which are just that, guidelines) lead installers in the direction of least risk of installation failure. Following their guidelines does not guarantee a floor that will not fail, just minimizes the risk of it. 

http://www.tcnatile.com/faqs/77-tiling-over-vinyl.html

This link shows their guidelines for installing over existing vinyl. There is nothing there about what you should use, just that you need to do your own research in thin-sets and adhesives for proper installation.

If you are installing tile over a rock solid substrate, you can get away with murder otherwise with regard to your cbu, I have seen jobs that have lasted 20 plus years using sheetrock (I still can't believe seeing this myself) as an underlayment without so much as a cracked grout joint. Cement board adds zero for structure, removing layers of flooring that pose a risk for bonding is necessary, or removing layers to deal with height issues is another reason, but removing a bonded layer of flooring for the simple purpose of putting an additional layer of cbu that provides zero change in the support is unnecessary, and when combining your installation with a decoupling membrane that separates the lateral movement of the subfloor from the tile installation itself, provided your subfloor structure meets the guidelines for deflection for your install as provided by the TCNA, you are simply adding unnecessary work and costs to the job.


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## TNTRenovate (Aug 19, 2010)

So your answer is risk it because there are inherent risks in anything? 

I am all for TCNA standards and I am quite aware at how and who put them together, but I would never install tile over vinyl. It's not that hard to remove and not worth the risk of it being an issue. While it may never be a problem, removing it guarantees it will never be a problem. 



To me, it's lazy not to remove the vinyl. You remove one more point of failure.


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## fcfc (Mar 10, 2012)

There are methods for installing ditra (specifically mentioned by the original poster whose thread we have hijacked here) over vinyl, there are guidelines linked to from TCNA for how to do it. There are reasons spelled out as to the how and why it works. You are defending doing extra work for the simple reason that it is to you a 'point of failure'. If addressed properly not only is not a point of failure, but simply an obstacle overcome by current methods and materials. Doing something simply because that is how its always been done or how you reason it should be done denies what is spelled out in both the TCNA guidelines and in the schluter handbook. 

Adding steps beyond this simply takes more time and materials, and gives you what. A floor that from a warrantee standpoint is exactly the same or possibly in some cases less than what you could have otherwise? If you remove a layer of 3/8 or 1/4" plywood that has been correctly installed, stapled in the proper pattern, seams offset to subfloor seams, covered with a vinyl over a 3/4" subfloor t&g that has also been properly offset and glued and screwed at the joists, only to turn around, rip all that off and install a layer of 5/16 or 1/2 CBU thinsetted and screwed to that aforementioned subfloor, with mesh tape at seams, have you in fact created more structure, or taken away from the support of the floor?

Wether installed over wood, vinyl, concrete, gypcrete, or even OSB, Ditra is rated based on the load and deflection of the support underneath it, not the type of floor per se as long as the proper manufacturer guidelines are met with regard to adhesives. Its a decoupling membrane, it separates the two layers intentionally and effectively allows a broader range of conditions. As stated on the first page of their manual,

Schluter®-DITRA is specifically designed to allow the installation of ceramic and stone tile over any even and
load-bearing substrate


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## TNTRenovate (Aug 19, 2010)

Ahhh...it just hit me you are a Schluter guy. That explains everything.

Oh since you brought up decoupling can you please show us an example of decoupling? An actual picture of tile decoupling?


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## GO Remodeling (Apr 5, 2005)

oh,dejavu all over again.


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## TNTRenovate (Aug 19, 2010)

Still waiting on the answer...:whistling:


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## GO Remodeling (Apr 5, 2005)

To be clear, this is 12x12 vct on a slab. Well adhered according to the OP. 

R.A.,
West Texas have any high water problems that might get up under the slab? Sure these tiles are well adhered? I thought about going over some VCT recently but as soon as the carpenter started hammering his plates, the tile started to pop off. Glad he started first. The vct will now be removed.

If you're confident about it sticking, I'd get a buffer/sander and hit it with a light sand paper to scuff it up and remove any wax. ( be sure it isn't that nasty asbestos type first). Then set the Ditra with a good modified and let it dry well. Set away.


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## HS345 (Jan 20, 2008)

TNTSERVICES said:


> Ahhh...it just hit me you are a Schluter guy. That explains everything.
> 
> Oh since you brought up decoupling can you please show us an example of decoupling? An actual picture of tile decoupling?


The term is actually *UN*coupling.


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## GO Remodeling (Apr 5, 2005)

as soon as you show me a picture of a steam shower that failed because of only water vapor.


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## TNTRenovate (Aug 19, 2010)

HS345 said:


> The term is actually *UN*coupling.


Just using his words. But the challenge still stands. And the silence is deafening. :whistling


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## TNTRenovate (Aug 19, 2010)

olzo55 said:


> as soon as you show me a picture of a steam shower that failed because of only water vapor.


Only if I made the claim...which I didn't, so yeah...


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## Rotten Apple (Oct 21, 2012)

Gosh!
I hate it when the kids fight. Thank you all for the input. I understand the options a lot clearer now. FYI, being wet out here is seldom a problem. Thanks again. R.A.


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## GO Remodeling (Apr 5, 2005)

R.A., stop back sometime. Don't be a stranger. We don't always argue. Well everyone except Rob. But he makes it interesting (most of the time). HAHA.


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## TNTRenovate (Aug 19, 2010)

olzo55 said:


> R.A., stop back sometime. Don't be a stranger. We don't always argue. Well everyone except Rob. But he makes it interesting (most of the time). HAHA.


One cannot argue alone. :whistling


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## GO Remodeling (Apr 5, 2005)

Not true, Rob. I have ongoing arguments with myself. Sometimes I even win.


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## The Coastal Craftsman (Jun 29, 2009)

I am currently on a job where i was weighing up putting tile over the VCT but decided against it. it really dont take any time at all to take them up and grind down to clean concrete. This 70sqft took an hr to take up and grind. 

i can now leave the job not anyway at all concerned about that VCT causing issues.


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## MIKE ANTONETTI (Jul 17, 2012)

Next question- can I install ceramic tile over gluedown carpet using thinset? I figure the carpet is acting like fiber reinforced concrete! Am I wrong ? Rhetorical question for now , or I may be on to something( not on something).


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## The Coastal Craftsman (Jun 29, 2009)

MIKE ANTONETTI said:


> Next question- can I install ceramic tile over gluedown carpet using thinset? I figure the carpet is acting like fiber reinforced concrete! Am I wrong ? Rhetorical question for now , or I may be on to something( not on something).


You can if you use the right type of trowel.


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## ohiohomedoctor (Dec 26, 2010)

Wtf :laughing:


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