Installing Tile On A Concrete Floor In A Basement... Do I Need A Membrane?

EZ Mode

Customer wants to tile the concrete floor throughout their entire basement. No problem, I said, but I'm wondering if I need a membrane such as ditra between the tile and the concrete, as the little voice in my head's telling me that slapping tile on thinset over concrete is unwise. What do you guys think?

MattCoops

Over time, expansion and contraction may cause tiles to crack. Depending on how big the area is, you may need an expansion joint.
But troweling down some thinset and Ditra would be a good idea.

The reason why tile lasted so long in places like the ancient Egyptian pyramids is because they poured a layer of sand between the substrate and mortar bed. Much for the same reason as your thinking.

Good idea.

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Matt with Cupan Custom Tile & Paint of Lowell, Massachusetts
Design and installation of ceramic tile and natural stone for floor, wall, and countertops
(978) 601-8774 | cupantile@gmail.com | view tile pictures and more

POOLMANinCT

I'm planning on using ditra in my bathroom. only because research & advice of some trusted pros on this board....

I'm used to laying over pored slabs & pools. something about the ditra seems "hoakie" to me. though its mechanical properties make a lot of sense. so ditra it will be.

anyone ever pull up ditra?

ty

ray

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Bill_Vincent

Let me put it this way-- it never hurts to Ditra the floor. However, if that concrete's been there for years, and there's no real cracks in it, I'd go right on the concrete and not have a problem guaranteeing it. If there ARE any cracks, I'd check them to see if there are any with one side higher than the other. If that's the case, I wouldn't tile it at all, because NO membrane, not even the "legndary" Ditra, will protect the tile from vertical movement.

Ray-- I thought the same thing before I used it the first time. Schluter's rep had come to the local Dal warehouse and shown it to us, and my attitude was "Yeah, right. You got a bridge in your back pocket?" The first time I ever used it, it was due to a recommendation from Dave Taylor at tile-experts.com. There was someone who'd contacted him thru John Bridge's site from Rowley, Mass., who'd had a kitchen floor installed, and the guy came in and stapled 1/4" plywood over vinyl and luan. It took that floor 6 months to fail. So I went in tore out the old floor put down the Ditra and set glazed porcelain with unmodified thinset. There was so much I was doing on this job that went against everything I'd learned about tile to that point, that I had to get it in writing from Dave as well as the Northeast Schluter rep, Bryant Bouchard (the guy in the Kerdi video), that if this floor failed due to anything other than workmanship, they'd back me on it. That was almost 4 years ago, and that customer has already given me several other customers in her area, and I'm about to do a family room for another of her friends this april, so I know for sure that floor has held up fine. One other thing-- a week after that kitchen got tiled, a 450 pound Wolfe gas stove got wheeled across the floor.

The stove:

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EZ Mode

5,000 years of engineering theory can't be wrong, lol!

The job is for a close friend so we're not making a killing, but I'll definitely talk the guy into paying for a layer of ditra... I'd hate to see my work fall apart. Thanks everyone for the input and advice.

islandboy

So what would be the cost difference between sand and Ditra these days? For a basement application.

Lazarus

Forget the sand...you ain't an Egyptian! (Go with the Ditra)

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Bill_Vincent

You don't have to be. You've never heard of a sand cushioned floor? I've never done it with tile, but I've installed several sand cushioned terrazzo floors. The sand basically goes down just like drypack. The only difference is the cement is missing. It gets wet down just as much, packed, and screaded off the same way.

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stroventile

Ditra is fine, but why go through that hassle. ECB membrane for the floor is more than sufficient and installs in much much less time and hassle. Depending on the thickness, not only is it crack suppression membrane, but also can be water proof and sound proof. Great replacement for old cork installations in condo's that have cement floors.

I happen to disagree with bill vincent on the existing cracks or no existing cracks. Thermal expansion area's should be membraned or have expansion joints placed in the floor. Either premade metal with silicone or pure silicone expansion joints. If its a basement and they just don't care or do not have the extra money for membrane..then you can squeak by...but if its not a financial concern, membrane it. Worst case, if there are existing old cracks, then get some wicking paper or even small amount of membrane and cover those. Anything to prevent damage to the new installation for now and later.

JonM

http://www.youtube.com/watch?v=f6FyWs2WZ1k

css

Ditra is ok . a few things i dont like about it
1 is the additional height added to floor
2 in wet areas where does the water go after gets through the grout and the thinset. answer is no where it sits in ditra channels and starts that horrible process we know as molding.
3 on large applications even an experienced installer can rarely smear thinset and then roll out ditra before overglazing. Not good for bond.

I do however always install a anti-fracture membrane over concrete in basements or smooth troweled concrete most thinsets even the best will shear from a smooth troweled or sealed concrete floor.

Have any of you used ardex yes ardex products for tile install or anti-fracture/waterproofing. there products are awesome maybe better than any i have used. for anti-fracture use ardex 8+9 is two part system you mix and roll or trowel on price is good also.

Lazarus

1) I find an eighth of an inch isn't excessive in most applications.

2) The depressions in the Ditra are quite shallow and "hold" very little water. Anything above this tiny amount will simply not penetrate. The water has nowhere to go. It will evaporate and dry out.

3) With one helper, mixing DitraSet to the proper consistancy and not attempting to spread more than a reasonable area, I have never seen this as a problem.

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Bill_Vincent

About 10 years ago, I traveled around the country with a company out of Coral Springs, Fla. tiling malls for Simon DiBartello, and JC Pennys. Many of the malls we tiled got ECB throughout the mall. I spent many days going back to malls that were already completed with two or three man crews to replace tiles throughout the malls that had cracked as a result of the compression that the ECB allowed. After a a few malls giving us the exact same problems, they got away from using ECB.

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css

it may dry out in Texas but in the northwest i have torn out ditra from decks and large masterbath floors where mold was present.

Bud Cline

Css,

I'm sure that's true but the DITRA didn't cause the mold in any of those cases, the installer caused the mold.

MattCoops

No, moisture and bacteria caused the mold.
Ditra claims to be waterproof when coupled with its Kerdi Tape.
The "pockets" in the Ditra then act as dishes to store water that seeps through grout lines.

The good thing about durock, and other CBU products is they soak up water, like a spong, not hold it, like a plate.

__________________
Matt with Cupan Custom Tile & Paint of Lowell, Massachusetts
Design and installation of ceramic tile and natural stone for floor, wall, and countertops
(978) 601-8774 | cupantile@gmail.com | view tile pictures and more

Bud Cline

Coops your comments never cease to amaze me! THAT above statement is pure and simple total nonsense.

MattCoops

Bud, you should try installing Ditra.
I didn't remember them using it at the CTEF classes.

By the way, I like that your name is Bud. You can call me every name in the book. All I can call you is "Bud".

__________________
Matt with Cupan Custom Tile & Paint of Lowell, Massachusetts
Design and installation of ceramic tile and natural stone for floor, wall, and countertops
(978) 601-8774 | cupantile@gmail.com | view tile pictures and more

Bud Cline

Yow, I heard you were there...and quite entertaining from what I understand. So you are saying you can't support your earlier statements?

MattCoops

sure I can, just contact your Schluter rep and have them contact me (my number is published in my signature)
You can even refer them to ALL my online posts.

__________________
Matt with Cupan Custom Tile & Paint of Lowell, Massachusetts
Design and installation of ceramic tile and natural stone for floor, wall, and countertops
(978) 601-8774 | cupantile@gmail.com | view tile pictures and more