# Laying new tile on top of existing tile??



## Bergmeister (Feb 17, 2011)

Looked at a potential new job two nights ago and here's the issue. 

The existing tile floor, installed in 1973 is layed on what appears to be a 3 to 4 inch pad/bed of concrete. Normally i would remove the existing tile and install backer board and then the tile. However the home owner and myself as well would rather not demo all the existing concrete.

Any suggesstions on how to assure the new !8"x18" tiles will hold up?

if it matters the existing tiles are about 3"x4" and glazed finish. Its not a slab home, theres a full basement And one more additional issue; a section will be near the fireplace, log burning. In this home the floor is the floor to the fireplace, no raised hearth. Perhaps thats why the tile floor is on top of the bed of concrete.

thanks in advance.


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## Tech Dawg (Dec 13, 2010)

Chip the tile up and if the mud bed is not smooth pour a SLC or skim it and then tile :clap:


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## robert c1 (Mar 11, 2007)

I've never heard of anyone trying to lay tile over tile. You may be in Neil Armstrong territory. Carpe Diem and let us know how it works.


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## Bergmeister (Feb 17, 2011)

Not looking to explore new worlds although i was under the belief that so long as the existing tile and base are sound it's doable? 

Removing just the existing tile would be ideal, I'll address this option with the client.


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## WJTR (Feb 28, 2010)

*tile over tile*

I once or twice saw guys (I know) and are good mechanics use a special etching agent which is painted over the existing ceramic. It actually turns the tile a funky color and basically etches the glaze off of the tile and then seen them lay new tile over it. I know they had no problems but I don't know the name of the product.


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## mikeswoods (Oct 11, 2008)

If the existing tile is sound---Scuff the glaze with an angle grinder----
--then use a two part thinset---unmodified mixed with a liquid additive.

Kera Bond and Kera Lastic by Mepei is a good example--works fine--Mike---


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## goneelkn (Jan 9, 2010)

I've done it the way Mike says, was just at that customer last week and no problems.
TCNA method TR712-09


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## Bergmeister (Feb 17, 2011)

Thanks everyone, greatly appreciated. 

I was just on the phone helping a finish carpenter buddy of mine who mostly does new construction figure out how to fabricate a way to install one of those mail slot deals that are used in entry doors. His client wants it installed in her wall, its a 1890's house in a historical part of town with plaster and lathe interior..... my buddy is so used to doing new work he's having a hard time im my world of dealing with restoration, remodel, and repair. So though i don't know any of you on here it's a blessing to get your help.

Berg.


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## PrecisionFloors (Jan 24, 2006)

As mentioned above, tile _can_ be installed over existing tile. Only you know how well the existing tile and mud bed is bonded. Are there ANY loose tiles, cracked grout joints, or indication of movement/flex? Any rice crispy sounds when walking it? IF...(big IF) I were to tile over a situation like that I would inspect every inch of the floor first. I would abrade the gloss off and put down a crack isolation membrane first. Nobleseal CIS or TS would be a good choice as it would not raise the floor up hardly at all. I would use a highly modified thinset as well and allow an extra day or two before grouting as the existing tile will absorb hardly any moisture. I'm sure some wouldn't take as many precautions as that but putting any floor over an existing one is risky in my eyes.

edit: Just looked. Noble doesn't specify existing tile as an approved substrate although I don't see why not. Can anybody clarify this?


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## PrecisionFloors (Jan 24, 2006)

PrecisionFloors said:


> As mentioned above, tile _can_ be installed over existing tile. Only you know how well the existing tile and mud bed is bonded. Are there ANY loose tiles, cracked grout joints, or indication of movement/flex? Any rice crispy sounds when walking it? IF...(big IF) I were to tile over a situation like that I would inspect every inch of the floor first. I would abrade the gloss off and put down a crack isolation membrane first. Nobleseal CIS or TS would be a good choice as it would not raise the floor up hardly at all. I would use a highly modified thinset as well and allow an extra day or two before grouting as the existing tile will absorb hardly any moisture. I'm sure some wouldn't take as many precautions as that but putting any floor over an existing one is risky in my eyes.
> 
> edit: Just looked. Noble doesn't specify existing tile as an approved substrate although I don't see why not. *Can anybody clarify this?*


:whistling Figured you blue kool-aid drinkers would be all over this, either shootin holes in it or confirming it :laughing:

Seriously - anybody know?


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## CO762 (Feb 22, 2010)

ghetto/handyman stuff


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