Rectified Porcelain, DITRA, and unlevel surface tips

superspeck

I'm installing a 12x24 rectified porcelain floor tile with a 1/8 grout line on a slab-on-grade with DITRA applied. It'll be set in a 1/3 offset pattern -- so the first tile will be 8", the 2nd one 16", the 3rd the full 24".

My main questions -- with a tile this flat and without variation, what are the best ways to avoid or hide lippage? The floor is not QUITE level; it has about a 1/8" over 2' wave in it; in other words, every 4 feet there is a dip about 1/8" in the middle. I COULD get self-leveling concrete poured in here, but it seems like a bit of a waste when the variation is that slight. I've got the high points marked on the walls and was planning to use a 1/2" square notch to give myself a little extra wiggle room.

Any pros want to weigh in here? Since I'm laying the DITRA over it first with a 1/8" v-notch, is that going to amplify or help hide the high spots?

Besides self-leveling... Is there any prep work I can do to help myself keep things straight, level, and otherwise happy?

This is the first full floor I'm doing, but I've installed tile using thinset before. (Bathrooms & Backsplashes...) Just haven't done a large area with a lot of precision... I'm only doing 100 sq ft here, but I'd like to make it look really good.

superspeck

(Oops, I should've put this in the Tile/Ceramics/Marble subform. Sorry. Admins, plz to move?)

JazMan

The industry standard for flatness is: "within 1/4" in 10 ft. AND 1/16" in 12" of the required plane". Your floor may be close to this standard, I'd have to know more. Plus, with large tiles I recommend that the floor be within 1/8" in 10 ft. instead of 1/4".

There is inherent lippage with every installation. All tiles have an inherent amount of warpage. How much? Don't know, it depends. Tight joints make it difficult to avoid lippage. Rectified tiles make it harder to control lippage. Floors that are not flat can create lippage. Using regular thin set mortar with large tiles, and/or not mixing and applying it correctly, creates lippage.

I'm not sure what you mean here, or how the 1/2" trowel is gonna correct the high spots.

Patching the floor should be done before you install Ditra.

!/8" V for Ditra? Who told you that? Installing anything can not improve the situation. The humps will get a little bigger is all.

You need to lower the high spots, and raise the low spots. Flat is what you need, level is nice, but the floor does not have to be perfectly level. Your option.

Jaz

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