Need Help with TCNA Standards please

Discussion in 'Ceramic & Stone Sales and Installations' started by SteveG, Nov 15, 2017.

  1. SteveG

    SteveG Pro Member

    Hey guys,

    I have 2 installations I need to justify to a builder, and I need a hand finding the TCNA standard to prove we installed correctly.

    First is some 6x6 quarry tile, installed on new, flat concrete. The GC is claiming we should have put Ditra under it, but our guys don't think that Ditra would be necessary or appropriate for that. I found online an old copy of the TCNA standards and it appears we are correct, but I'd like to get the excerpt from a more recent copy of the book. I'm referencing F112-03.

    Secondly, same situation with a 2x2 mosaic tile that again, our guys laid right on the slab with no Ditra. Same concerns as above. Can anyone help me make sure we're correct here, and maybe give me a hand with the latest standards?

  2. SteveG

    SteveG Pro Member

    I just purchased the 2017 TCNA book also and solved my own problem. I can't seem to delete this post, but feel free to remove it, Jim.
    Last edited: Nov 15, 2017
  3. Jim McClain

    Jim McClain Owner/Founder Administrator

    It would be better if you share what you learned with the rest of us. Thanks.
  4. SteveG

    SteveG Pro Member

    What I learned was the crack isolation is optional according to the handbook. Basically the builder wanted us to put Ditra under 6x6 quarry tile with epoxy grout, and under 2x2 mosaic tile. Turns out, it's not necessary.

    Really I side with our guys, but I just needed to print out the correct method. I ended up on F115-15 plus a copy of the Schluter installation specs. That should be plenty.
  5. Mark Brown

    Mark Brown On The Surface Flooring I Support TFP

    when is crack isolation ever mandatory? This would be news to me and would love to be knowing.
  6. Mike Antonetti

    Mike Antonetti I Support TFP Senior Member

    It’s based on what the specs were to install. If the bid was for Schluter under it, then it would have to be ripped up. Or if they quoted standards necessary.

    What did he prep very to you to justify needing Ditra? Did you become s member of NTCA?
  7. epoxyman

    epoxyman Pro Member

    I get my newest TCNA books from our local Dal-Tile here in town for free.
  8. SteveG

    SteveG Pro Member

    Well, the Ditra was in the spec - but in the one room it was under 1x1 tile which Schulter said is a no-no so we're good there. In the other room it remains to be seen what will happen.
  9. Mike Antonetti

    Mike Antonetti I Support TFP Senior Member

    I personally do not like Schluter Ditra, maybe in limited situations like over plywood. Liquid crack isolation was my go to. Membranes are misunderstood, misapplied or nonexistent. I have seen so many attempts from Duct tape to 6” wide bands.

    You may have to warranty for quite awhile, and I’d advise you to join NTCA(500$?)get the vouchers(1200$?) to offset/supersede the membership and get some advice from them if the GC presses on. They have had many seminars on contract obligations, James Woefel is well versed in them. Good organization, good people!
  10. Mark Brown

    Mark Brown On The Surface Flooring I Support TFP

    Crack supression membrane has become such a farce it kind of makes me laugh. I see that stuff going everywhere and most the time... everywhere it isn't needed. Some head about it once then the big orange machine of Schulter went into high gear and convinced everyone they needed it. Sure it isn't ever a bad idea.... if you have endless amounts of money to burn but my god people.
  11. Mike Antonetti

    Mike Antonetti I Support TFP Senior Member

    I prefer to spot treat cracks meaning an old slab where it’s cracked then I apply the membrane close to 3 tile wide. Control joints as well and soft joints in the grout. In the Villages, yes the famous community where they pop the blue pill there is one neighborhood where the mapeguard membrane is mandatory,(code) so I’ve heard. That is why I dislike working over there, the stuff is like rubber cement and thinset.
    • Like Like x 2
  12. Mark Brown

    Mark Brown On The Surface Flooring I Support TFP

    Duct tape over that cracking and go baby. BOOM!

    I dont think the Romans had ditra and their tile STILL look amazing :)
    • Like Like x 1
  13. kwfloors

    kwfloors Fuzz on the brain Charter Member I Support TFP Senior Member

    I have seen whole basements covered with ditra first around here. Otherwise this happens. cracked tile.jpg
  14. Mike Antonetti

    Mike Antonetti I Support TFP Senior Member

    Problem with thinset method is that it usually bonds so tightly to the slab that when slab moves the tile is not flexible and 4” thick movement is no match for 1/2” thick tile.

    Another development here put down sheet vinyl backing felt. Glued it down using cheap adhesive then thinset to that. Problem is the adhesive failed due to moisture and alkalinity, hollowness, tenting occurs but makes it easy to take up.

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