When To Use Schluter Ditra For Tile

Learn the reason to use the Schluter Ditra underlayment product for tiled floors.

The “decoupling” feature of Ditra is really useful in certain situations, such as a cracked concrete subfloor. We’ll get up close with this product and show you how it works.


itdock says:

Schluter reccomends MODIFIED thinset when you install Ditra over plywood or OSB substrates.  Unmodified thinset used in that installation can lead to system failure.

Diana Anderson says:

Can this be used if for instance a water line would break and flood the area or a sump pump would back up or quit working. The underlayment will get wet and this will not work as water will get trapped?

rightnow77 jack says:

Interesting video buddy…

Francisco Garduno says:

I use laticrete strata mat. Ditra is way over priced.

Henry Peterson says:

Excellent description on the Schluter DITRA product. Thank you Sir!

badboy3985 says:

Thank you for such a well made video. is using schluter ditra on OSB subfloor recommended or necessary ? I have a kitchen area 12 ft wide and 20 ft long joists 1 1/2” X 9” 16” OC and it is stripped down to the OSB subfloor. I intend to tile it with 12”X24” porcelain tiles. my original plan was to cover the 5/8” OSB subfloor with 3/4” external grade plywood and secure the plywood to the OSB with flooring screws then install the tiles directly onto the plywood with modified thinset designed for plywood application and to avoid using backerboard or schluter ditra to reduce costs

greg l says:

how would u feel about using Harie backer instead on that cracked floor?

oarfish12 says:

Can I just use this membrane to install tile over varnished standard tongue and groove oak floors with plywood subfloor? I am trying to avoid removing the 3/4″ oak floor but without the added thickness of the cement board tile backing.

Elaine Leonard says:

I would like to know if it is possible to lay wood tile over wood tile, I was told that it can be done

manuel luz says:

Awesome video, thanks for the info

David R. Waligora says:

What about expansion and contraction of the polymer material? I’m talking about horizontally since that is the direction where the most material is oriented.

The Shluter Ditra product is manufactured from High Density Polyetheline plastic (HDPE) which has an expansion coefficient of about 67 – 10^6 in/in F.

Regular thinset mortar has an average expansion coefficent of 5.78 – 10^6 in/in F.

Therefore the Schluter Ditra product theoretically expands approximately 11.59 times more than the thinset mortar given any environmental temperature condition.

Wouldn’t longitudinal expansion and contraction cause unnecessary shear to the thin set mortar over time thus resulting in un-coupling?

ThatChickNYC says:

Hi.  I want to re-tile my kitchen and bathroom floor.  I believe it’s concrete underneath.  What I REALLY want is to avoid my tiles cracking.  they will be 6×24 ceramic tiles.  What is the best product (substrate) to use?  Do you recommend this or an alternative if I can’t find this?  Thanks

Matt McWilliams-Brousseau says:

We recently bought a home which has a mudroom with a concrete slab. At one time someone installed a laminate floor directly on top of the concrete slab. Later someone installed a carpet on top of that laminate floor. The issue is that during the wet months water seeps up through the concrete slab and absorbs into the rug. I don’t know the extent of the cracks but our plan is to rip both layers of flooring out and install tile instead. Would schluter-ditra be a good choice for this application or should I use DRIcore OSB Sheathing? If we wanted heated floors, could we use the ditra heat system in place of either of these or would we need to use a combination of them? I just want to make sure we wont have issues with cracked tile or tiles coming loose due to the cracks in the slab or water coming up through the concrete slab. TIA!

David Patheyjohns says:

I used a notched trowel 3.5 for sticking the ditra to ply. Always phone manufacturers for advice when using tiles to ditra. They know best and have tested things.

Bobby Bhasin says:

awesome video

NightHawk says:

do you just put it over the cracks or cover the whole floor?

Mike Taylor says:

Very informative, thanks!  For concrete installs, what do you think of paint-on products such as RedGuard or Hydroban?

Chilidoggs Reef Attempt says:

arent you supposed to use a modified poly. thinset?

Rikai Pittman says:

Do I have to level the concrete sub-floor before I put this underlay down? or does this underlay substitute for that?

Dirk Lentfer says:


Bernie Marchand says:

Watch the disc that comes with the drain kit/ shower kit it explains the difference.

MODIFIED- If used underneath the product air can’t reach it to cure the thin set because modified needs air to properly cure. if you decide to use polymer/acrylic product it will take forever or will not bond or cure properly and voids the warranty.

NON-MODIFIED- If used underneath the product will cure, it DOES NOT need air because its curing process is a chemical reaction (like concrete) and DOES NOT need air. Every pro knows this, its in the specs. Read the specs, watch the orientation.

Christopher Hensley says:

Did I miss the answer on when to use? 8 mins of what the product does but not when to use in compared to other products like backer board.

Thomas NorthCastle says:

I have been using and installing Schluter products for about 18 years. I will NEVER use anything else. Schluter actually has their own mortars as well as their own trowels to use with the Ditra and Kerdi. Schluter will offer incredible trainings for installers. Trainings are 2 days and they, pay for your hotel, breakfast, lunch and dinner!!! NOTHING that this company does is second rate.

James Kuller says:

So the tile is floating on the plastic. Worst part is this product is more expensive than the flooring going over it.

Ice Fishing says:

Could you use ditra over the hardibacker? To protect from movement and such

Josh Lopez says:

Now how would you go about removing this underlayment? Would u have to run new wires. Floors is beingh re done it already has this system.

Most Likely We Do It Services says:

The customer had that installed on 3/4 plywood on deck that serves as a roof to his garage. I saw the install. The installer used the tape and sealer at joints. The crap leaked like all get out into the garage.

emil dekoven says:

VERY definitive & clarifying about Ditra’s use over concrete, but what about tile’s movement over panels or other substrates…..most of which are liable to settling and shifting…..?

Constitution_89 says:

Thanks for this informative video. My big question is this: Can you tile “over” an outdoor concrete slab that has expansion joints about 3/4″ wide without replicating the expansion joint in the tile installation using Ditra? The slabs were poured long ago and surround a circular pool, and I’d like to have the tile continuous without expansion joints, can that be done using the Ditra? I’d appreciate anybody answering this question, Thanks.

Tonybone Robert says:

Shluter is way over rated.

Gina Sofia says:

This video is great. Thank you so much for taking the time in being so thorough. I am going to be doing a DIY tile project, and you have helped me tremendously.

aerodicus says:

Thanks man!

NewShockerGuy says:

According to Schluter you are supposed to use Modified thinset to attach the Ditra to the floor, then unmodified to attach tiles to the ditra. I am doing this now and that’s exactly what the book that came with my ditra mat states…

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