# Should I Demo Up The Existing Mortar Bed For New Marble?



## bluethumbnail (Nov 5, 2005)

I'm going to demo up a porcelain tile floor and lay 12" marble over about 330 sq. ft. in an eat-in kitchen area. The existing 6" porcelain tiles were laid over a 1-1/2" mortar bed with steel mesh, over wood sub-floor. During "exploratory surgery" the first couple of tiles came up clean with no damage to the mortar bed. 
Q:
Can I lay the marble over the existing mortar bed if the rest of the tiles come up as cleanly as the samples? If I don't have to jackhammer out the entire 330 sq ft mortar bed (my original plan), I can save this lady a WORLD of dust! She will be leaving for a couple days during demolition because of the inevitable dust which, I am taking extra measures to control.

What do you think? Can I reseal the bed and use it again?

Thanx!


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## angus242 (Oct 20, 2007)

Personally, I always demo and start with a clean slate (no pun). It's the only way I can guarantee my work. Since you've already told the customer you were going to demo, what can it hurt? I'm certain she'd prefer a dusty job well done rather than hope the dust free job lasts.
As for what's under the bed, I always say...you don't know what you don't know. Why take a chance? I vote for demo.


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## GoodHouse (Sep 3, 2007)

Ripping up a wet bed like that is pretty much the worse as tile demo goes. If your tile is coming up that easy i would leave it down. Those beds were built to last. I have rarely ever seen a cracked tile installed over a wet bed. You have a serious amount of time in labor, clean up and sweat ripping that out. Particularly if the cabinets are installed on top. 
Good luck


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## Norrrrrrrrrrrrm (Jan 20, 2007)

I would also leave it. I would use a chipper to pop the tiles faster and cleaner. If there are any voids in the floor when you are done, just fill them with mortar or thin set. 
You might know this already, but if you use marble, you should use white thin set. The dyes in gray can bleed though over time causing discoloration.


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