Ditra XL, 24x24 Marble = Settling/Lippage Issues - Any ideas?

[GarretHouston]

Good afternoon,

I am doing a Ditra XL install (about 1,400 square feet) of an entire first floor to a house. The flooring material is 24" x 24" cappuccino marble. Based on a recommendation from my Schluter rep (due to some moisture/vapor issues in the slab), I am using Ditra-set to adhere the Ditra XL to the slab, and am also using Ditra-set to affix the marble to the Ditra XL. I am using the Tuscan leveling system as well.

After completing the Ditra XL install, yesterday I started installing tile, and did a 5' by 10' area by the front door. I came back to the house today and I noticed some severe lippage issues (1/8" in some spots) that must have occurred from settling from the (heavy) weight of the tile, despite using the Tuscan leveling system.

We don't have vertical room to use mud (or mud with Ditra-set) on top of the Ditra XL, and Schluter does not want me to use any mud, slc or leveling compound under the Ditra XL because of the moisture issues.

Any ideas on how to deal with this?

[cx]

Welcome, Garret.

I just can't imagine how your tiles could individually sink while the TLS was in place.

If that's actually the case, I think you need to talk with our friend Mick who created that system. I'll see if I can get him to take a look at this, but he can also be contacted through the link to the right side of the page.

You got some photos of this floor with the problem in place?

[eurob]

Garret,

Is the marble moisture sensitive ? That's the only way to have lippage with the TLS. The corners will curve no matter what.

Talk to the supplier for the marble . If the marble is not moisture sensitive , then it is due to improper setting of the TLS. But this can be seen at the same moment as the installation .

[ceramictec]

if you have slow rolls in the slab or even worse nice divot, even using the TLS wont help you get the tile flat. you will need to prep your floor first and then use the Ditra and the TLS.

it would be useless to screed/float in the low spots with the Ditra already installed.

I would have used a few thin layers (allow each layer to dry) of Ditraset to fill in the divots first before installing the Ditra.

[Toddman]

Just curious as to why your using the Ditra XL instead of regular Ditra?

[MICK1]

Hi Garrett,

Is your marble gaged, and if not, are you using the straps for ungaged?
Could you, please post some pics with the TLS on top of the floor, after has been set?
Roberto, you are correct.

Thank You.

Mick.

[Houston Remodeler]

Sounds like the thinset may have been mixed too thin, which can easily be the cause of sinking tiles.

How flat was the substrate before the ditra went in?