How to install Ditra XL over concrete
In this video I want to show you how to install Ditra XL. Ditra XL is an uncoupled membrane used to separate the tile layer from the substrate. Concrete expands and contracts at a rate nearly three times that of tile. Stopping the movement of the concrete before it causes a stress fracture is of the utmost importance to me.
I’m using Ditra XL in this video because it will give me the desired transition from the bathroom to the hardwood floor at the doorway.
The use of an uncoupling may allows me to relocate all expansion joints to the perimeter of the room. If I didn’t relocate these to the middle of the room I would have to honor the stress crack in the center of the bathroom by cutting the tiles over it. It would create an unsightly installation and not have the desired effect I’m going for.
Another great thing about the way uncoupling membranes work is that I can use up scrap pieces and not compromise the installation. I’m not needing the floor to be waterproof for any reason, so I’m not worried about the number of pieces I’m using. If I were concerned about waterproofing it I would simply have to install Kerdi Band at the perimeter of each piece of Ditra XL I use.
Prior to beginning the recording we used a floor grinder to remove all potential bond breakers from the slab. This also opens up the pores of the slab giving the thinset mortar a better surface to bond to.
Since this is over concrete I’m using Schluter Set mortar for the installation. Schluter Set is their non-modified version and will stick just fine to the slab. I will also use the Schluter Set mortar to install the tile as well.
I’m using a 1/4x1/4 notch trowel to install the Ditra XL to the slab. Prior to using the notch side of the trowel I key in the mortar to the substrate with the flat side of the trowel. Keying the mortar into the substrate forces as much mortar into the crevices as possible. This will create a very strong bond to the slab.
When I set my first piece of Ditra XL into the mortar I use a concrete float to embed it. I go both directions with the float to work the mortar into the fleece of the membrane. When I set the first piece I peel up a corner to check for coverage. I’m looking for 100% transfer of thinset mortar to the fleece of the Ditra XL. I use the same method to install all the pieces of Ditra XL in this bathroom.
Hopefully you found this video helpful for your project. Be sure to click the subscribe button and ring the bell to keep updated with our latest videos. If you’re in the mid Missouri area and you’re looking for a tile installer, I would love to interview for your project.
EJ Flooring
(573) 289-1045
Certified Tile Installer #1329
www.ejflooring.com
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