Ceramic Tile Advice Forums - John Bridge Ceramic Tile

Welcome to John Bridge / Tile Your World, the friendliest DIY Forum on the Internet


Advertiser Directory
JohnBridge.com Home
Buy John Bridge's Books

Go Back   Ceramic Tile Advice Forums - John Bridge Ceramic Tile > Tile & Stone Forums > Tile Forum/Advice Board

Sponsors


Reply
 
Thread Tools Search this Thread
Old 01-10-2018, 03:13 PM   #1
tbb
Registered User
 
Join Date: Apr 2014
Posts: 21
porcelain adhesion

What can go wrong with setting 2"x2" porcelain with unmodified mortar over Ditra?

The last 4 SF of tile I set in the bathroom did not adhere and I have been able to pick it off with my fingers. I found this as I was cleaning the joints in prep for grouting.

- I used 1/8" DITRA, DitraSet, DALTILE 2x2 Keystone porcelain tile.
- I washed the tile sheets for good measure and let them dry prior to setting.
- I can see the towel ridges flattened off on the top of the mortar under the tile.
- There is the slightest bit of thin set on the bottom of the tiles and washed off under water while rubbing with my thumb.
- The DitraSet dried hard and adhered to the DITRA.
- There were some tiles that were 100% embedded. No mortar ridges just flat. These were accent tiles and had been back buttered.
- Most curious is that this installation overlapped some the same tile along one edge and the DitraSet is firmly adhered to the top of those porcelain tiles. Admittedly I scored the tops of those tile.

Best guesses:
- old mortar (bag was maybe 6 months old and had been open for 3 months ... there are no hardened granules in the powder)
- thin set skinned over before pressing in tile
- thin set was too wet ... it was mixed so that it would just start to sag on a trowel held sideways
- mortar drying too fast ... this section of tile was done after a change over to heating for winter

Ditra and DitraSet can not imagine anything other than the "best guesses" above that could go wrong.

Thanks
__________________
Thomas
tbb is offline   Reply With Quote
Sponsored Links
Old 01-10-2018, 04:21 PM   #2
rmckee84
Moderator
 
Join Date: Feb 2012
Location: Southern Illinois
Posts: 2,283
Sounds like thinset moat likely skinned over. Did these tiles have a glued on mesh backing? If you wash the back it could have smeared glue all over the backs and then inhibited the bond.
__________________
Jack of most trades, master of none...
Ryan McKee
McKee Construction & Custom Tile
rmckee84 is online now   Reply With Quote
Old 01-10-2018, 07:02 PM   #3
tbb
Registered User
 
Join Date: Apr 2014
Posts: 21
porcelain adhesion - no glue on backing to smear

Ryan,
Not a mesh as I understand it. Only 2 rubbery dabs at the sides.
I did not wash the failed tile differently than the other 15 SF that have not failed.
__________________
Thomas
tbb is offline   Reply With Quote
Old 01-10-2018, 09:47 PM   #4
rmckee84
Moderator
 
Join Date: Feb 2012
Location: Southern Illinois
Posts: 2,283
Got it, then definitely would lean toward either old mortar or skinned over thinset.
__________________
Jack of most trades, master of none...
Ryan McKee
McKee Construction & Custom Tile
rmckee84 is online now   Reply With Quote
Old 01-11-2018, 07:06 AM   #5
Kman
Moderator
 
Kman's Avatar
 
Join Date: Nov 2006
Location: NW Arkansas, Ozark Mountains
Posts: 9,015
That's usually a sign that your thinset had started to dry before it was covered.
__________________
Kevin

The top ten reasons to procrastinate:

1.
Kman is offline   Reply With Quote
Old 01-16-2018, 07:54 AM   #6
MAPEI - Technical Service
Company Representative
 
MAPEI - Technical Service's Avatar
 
Join Date: Jul 2013
Location: Florida
Posts: 772
I don't know the root cause of your failure but it cuts to the heart of why the tile industry recommends polymer modified mortars for porcelain. The tiles you are describing typically have a flat back and close to 0% porosity, there is nothing for a mortar to mechanically 'grab' onto. When there isn't a mechanical bond with the cement, there needs to be an adhesive bond with the polymer. Since you don't have any polymer, you don't have any adhesive bond.
__________________
Dan

http://www.mapei.com/US-EN/
MAPEI Product Tech Support Hotline 1-800-992-6273
MAPEI - Technical Service is online now   Reply With Quote
Reply

Stonetooling.com   Tile-Assn.com   National Gypsum Permabase


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Thinset adhesion dlcooper521 Tile Forum/Advice Board 4 01-09-2015 05:34 PM
Tile Adhesion??? Weekday Tile Tile Forum/Advice Board 27 03-17-2010 05:09 PM
proper adhesion Michaela Tile Forum/Advice Board 9 01-30-2006 06:39 PM
Porcelain tile adhesion bwjohnson1927 Tile Forum/Advice Board 2 01-18-2006 10:41 PM
mortar adhesion ? fishon Tile Forum/Advice Board 2 06-05-2003 07:55 AM


All times are GMT -6. The time now is 09:03 AM.


Sponsors

Powered by vBulletin® Version 3.7.4
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
Copyright 2014 John Bridge & Associates, LLC