Prepare Your Floor for Tile the Smart Way: Install Schluter Ditra the alternative to cement board

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Thinking of installing Schluter Ditra as your underlayment instead of a cement board? If you’re preparing your floor for tile, Ditra is a smart, time-saving choice. It provides superior protection against moisture, offers better support and stability to tile floors, and is easy to install.

Are you ready to renovate your bathroom? 

If you’re putting down tile, I recommend this awesome product: Schluter Ditra uncoupling membrane

This is your underlayment, and it goes directly on wood or concrete, with your ceramic and stone tile on top.

One of the best features is the unique ‘dimpled’ texture that allows moisture to evaporate without damaging the tile floor above

You can use it instead of a cement board underneath the tile. The polyethylene material is thin, flexible, and easier to cut than cement board. 

Let’s take a look at how I installed it during my bathroom renovation. I’ll show you the best tools and materials to use and you’ll see why I prefer this product over a cement board any day!

preparing floor for tile with Schluter Ditra

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Underlayment for tile floors



Before you start

Installing Schluter Ditra is an excellent way to prepare a floor for tile. 

Before you can use the product, you need to remove any old tile or flooring. Ditra can be installed over concrete or wood but not other flooring surfaces, so remove, level, and clean the floor before you start. 

STEP 1: Cut the Ditra underlayment

The first step is to cut the underlayment. And luckily, Ditra is easy to cut. 

All you need is a razor blade or scissors. I found the razor (utility knife) to work better.

cutting Schluter Ditra with razor blade
cutting Ditra around toilet flange

Take the time to cut the Ditra to fit in the space. It’s ok if you have seams – I will show you how to connect those later. 

The only issue I had while cutting was the length of my room and the angles because I had to cut the membrane in the small, confined space of my bathroom.

Schluter Ditra cut to fit bathroom floor

After the underlayment is cut to fit in the space, carefully roll it up and set it aside. It’s a great idea to label the pieces if you have multiple. 

SIDE NOTE: You can also use Schluter’s video on how to install Ditra

STEP 2: Mixing the thinset

You need a special type of thinset to install the Schluter Ditra. I recommend using Schluter’s thinset called All Set to get the best results.

Schluter All set

Follow the exact instructions on the package.

I used a scale to weigh the water and the mix. This was an easy and precise way to ensure I got the correct consistency. 

I found it helpful to use half a 50-pound bag every time I mixed a new batch. There are two reasons for this: 

1) It was a good amount to work with at a time (didn’t set up before I would use it all)

2) If you mixed the full 50-pound bag all at once, you would need a bigger drill, or you would risk overheating your cordless drill

To begin, fill the bucket with water and pour in the mix.

Next, use the drill paddle attachment to mix the thinset (mortar). 

Make sure you follow the instructions on the bag. The package will tell you the amount of time that you need to mix. Normally, there’s a mixing phase, a rest, and then another mixing session.

mixing thinset with drill and paddle attachment

The product I used required a mix for 5 minutes, rest for 10 minutes, then mix for another 3 minutes before it was ready. 

STEP 3: Installing the Schluter Ditra membrane 

After your thinset is mixed according to the instructions, wet the floor with a damp cloth or sponge. 

Then, apply the thinset to the area with the trowel. 

I like to use both a 1/4″ by 3/16” v-notched trowel and a 6” taping knife to set the thinset on the floor.

You will cover the full area with the thinset, ensuring there are grooves from the trowel notches in the thinset.

applying thinset to floor to install tiles

After the area is covered with thinset, lay the floor membrane on top (the bumpy side will be up). Adjust it if needed.

laying Ditra over wood for tile floor

SIDE NOTE: It’s ok if you need to step on or place your knee on the membrane. 

Then, use the rubber float to embed the membrane to the floor. This will remove any bubbles or excess thinset but, most importantly, allow the membrane to adhere to the floor.

adhering Schluter Ditra to wood floor

Lift a corner of the membrane to check the coverage of the thinset. You will know if it’s properly installed if the thinset is on both the floor and membrane (will look like you squished something together, then pulled it apart). Make sure you reinforce the membrane in this corner before you move on. 

Continue this process until all the Ditra membrane is installed in the area. 

STEP 4: Waterproof seams and walls

If you have seams like I did, apply a strip of membrane tape to the joint. 

The membrane tape is applied the same way as the Ditra membrane. 

Apply thinset to the seam using the notched trowel. Then, apply the strip of membrane tape to the area. 

applying thinset to Ditra seam

Use the taping knife to smooth the strip and remove any excess thinset from the area. 

If you have a bathtub, you’ll first want to use Kerdy Fix between the membrane and the tub to give you a waterproof finish next to the bathtub.

Apply a bead of the Kerdy Fix along the bathtub.

schluter kerdi fit

Then, apply the strip of the membrane tape against the tub. 

It’s also recommended to apply this strip of the membrane tape around all the walls. 

SIDE NOTE: I didn’t have enough of it to go all around the room, so I just did the area where the toilet and the sink will be. 

If you get any thinset on the walls, use a damp sponge to wipe it off before it dries.

After you have waterproofed the area with the membrane tape, you can allow it to dry for 24 hours, or you can start laying tiles immediately. 

Here is what our bathroom floor looked like after installing and allowing the Schluter Ditra thinset to dry completely:

schluter ditra membrane installed on bathroom floor

Would I recommend Schluter Ditra over a cement board? The answer is yes! 

I thought the Ditra was much easier and quicker to install than the cement board and works even better.

Here is my bathroom completely finished:

bathroom with black floor tiles, grey vanity, and white shower tiles


Are you someone that does better with visuals? Check out the full prepare your floor for tile project video below, and don’t forget to subscribe on YouTube, so you don’t miss out on future projects!

installing Schluter Ditra with video play icon overlay

Use this tutorial to prepare your floor for tile the smart way by installing Schluter Ditra because it’s a fantastic alternative to using cement board when tiling.

Prepping bathroom floor for tile with Ditra
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