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


Thread Tools Search this Thread
Unread 01-17-2020, 09:59 AM   #1
Registered User
Join Date: Jan 2020
Posts: 3
thinset for tile over tile? - edited

newbie here and have done my own tile a lot in the past as a homeowner and as a GC, but been in a desk job for years now and a little fuzzy.

Currently in a home that unfortunately only has one bathroom. Getting ready to retile and wanted to go over the old tile to save time and effort vs ripping it all out. The extra height is also actually helpful in my situation. Old tile is a cheapo 12x12 fairly smooth glazed tile. Also putting a small 20"x 6 foot section of heating wire under part of the new tile.

Now, if I'm laying over top, what thinset/mortar/etc will give me the best adhesion to the old tile? Conversely, is this just a horrible idea? I did a test spot and put some cheap premixed on top of a tile to test adhesion and wasn't super thrilled. Did wash the tile first and hit one section with some 40 grit to rough it up.

Thanks for the advice.

Editted- original post asked about mastic

Last edited by iwhitevt; 01-17-2020 at 02:11 PM.
iwhitevt is offline   Reply With Quote
Sponsored Links
Unread 01-17-2020, 10:01 AM   #2
Moderator emeritus
cx's Avatar
Join Date: Jul 2001
Location: Boerne, Texas
Posts: 90,748
Welcome, Ian.

I'm guessing you're re-tiling the floor?

cx is offline   Reply With Quote
Unread 01-17-2020, 11:35 AM   #3
Jim Farrell Tiler
dont blame me i didnt vote for him
Jim Farrell Tiler's Avatar
Join Date: Aug 2004
Location: Dunedin New Zealand
Posts: 1,754
the mastic will probably never dry
Jim Farrell Tiler is offline   Reply With Quote
Unread 01-17-2020, 11:54 AM   #4
ss3964spd's Avatar
Join Date: Jul 2005
Location: Fairfax, Va
Posts: 3,317
Send a message via Yahoo to ss3964spd
Welcome, Ian.

Many challenges with using mastic, and one that springs immediately to mind is that the manufacturer of your floor warming system isn't likely going to condone using mastic with their product. And even if they did you'd have to apply it so thick that, as Jim says, it may never dry, and almost certainly not by the time you want to use it.

I've read here that some companies make a primer specifically engineered to be applied over existing ceramic tile that will allow you to use a thinset mortar to set new tile upon the old. Mapei I think is one, Laticrete might be another.

You'd have to, of course, ensure the old tile is still firmly set and that the floor is sufficiently flat for the size tile you wish to use.
If I recall correctly my memory is excellent, but my ability to access it is intermittent.
ss3964spd is offline   Reply With Quote
Unread 01-17-2020, 02:05 PM   #5
Registered User
Join Date: Jan 2020
Posts: 3
Sorry guys! got in a hurry and used the wrong word.. basically thinset/tile mortar. Just looking for whatever product would be best for setting new 6x24 tile over existing 12x12. Or if in reality I'm a dumba** for not taking the extra time/effort to rip up the old one.

iwhitevt is offline   Reply With Quote
Unread 01-17-2020, 08:14 PM   #6
Moderator -- Mud Man
Davy's Avatar
Join Date: Jan 2003
Location: Princeton,Tx.- Dallas area
Posts: 32,769
Nothing wrong with going over the old tile, especially if the added height helps you out. I would use a primer first, Customs makes one you can get for Home Depot, here's a link.
Mapei also makes one that can be bought form Lowes.

Davy is offline   Reply With Quote
Unread 01-18-2020, 10:54 AM   #7
Registered User
Join Date: Jan 2020
Posts: 3
iwhitevt is offline   Reply With Quote
Unread 01-20-2020, 07:37 PM   #8
Registered User
MAPEItyler's Avatar
Join Date: Jan 2020
Location: Deerfield Beach, FL
Posts: 19
Just make sure it is well bonded and clean. You can use a bond enhancing primer, it will increase the bond and make troweling over the existing tile easier. MAPEI has one called EcoPrim Grip. Then a quality modified mortar like Ultraflex LFT or Ultraflex 2 or better would suitable.

Happy Tiling.
Jim Whitfield

MAPEItyler is offline   Reply With Quote

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
Installing new tile over old mastic? zmusashi Tile Forum/Advice Board 7 10-08-2016 10:05 AM
Old tile with Mastic onto Thinset? D2Bernhard Tile Forum/Advice Board 6 07-14-2010 02:26 PM
TEC mastic & Tile Madam Tile Forum/Advice Board 3 09-29-2009 08:49 AM
Tile over Tile-Thinset/Mastic question dean0 Tile Forum/Advice Board 8 03-26-2009 08:55 PM
removing mastic from tile Unregistered Tile Forum/Advice Board 2 05-14-2004 07:36 PM

All times are GMT -6. The time now is 03:20 AM.


Powered by vBulletin® Version 3.7.4
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.
Copyright 2018 John Bridge & Associates, LLC