Replies

1. 
   BruceS | May 18, 2007 06:15am | #1

   How old ?  No guarantee as to workmanship ?

   Go to Breaktime and get a contractors viewpoint, you'll get a better answer there.

   Work Safe,  Count to 10 when your done for the day !!

   Bruce S. 

    

   
   

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   Edited 5/17/2007 11:17 pm ET by BruceS

2. 
   MikeHennessy | May 18, 2007 01:50pm | #2

   A cement finisher once told me "There's two kinds of concrete - concrete that's cracked and concrete that's gonna crack." The cracks that have developed in the concrete floor are what is causing the tile to crack -- it's called telegraphing. If the concrete is old, it may be that no more cracks will develop. However, that doesn't mean the existing cracks won't continue to move a bit, causing any new tile placed over them to crack as well. The solution to this is to install an isolation membrane between the existing floor and the new tile. Ditra, by Schluter, is the current hot item. It's an orange, waffle mat that you put down on the floor before laying the tile. You can put this over the existing tile, but you may be limited by the extra floor height this would result in when placed over existing tile -- I'd guess close to an inch when adding the two together. If you have the height, you can skip removing the old tile. You can't skip the isolation membrane unless you want to see the cracks again in the new tile.

   Mike Hennessy
   Pittsburgh, PA

1. 
   kalman | May 19, 2007 04:14am | #4

   Mike. Thanks for the info.  Probably not the answer she will want considering the cost but if it  has to be done it becomes a "pay me now or pay me later" .. The consequences are such that she will be looking at the same problem down the road soon.   I will pass your suggestion on to her .Thanks,  Kal

1. 
   MikeHennessy | May 21, 2007 03:04pm | #6

   You're welcome.

   Although I'm a Schluter fan, there are cheaper options to Ditra (or similar isolation membranes). There are also products that bridge just the existing cracks that help somewhat. A tile guy should be able to tell you about them and give you the options.

   Ditra is about $1.50 / SF, plus installation. Not exactly "cheap", but not expensive either, especially if you're laying tile that will cost two to ten times that. I consider it a good insurance policy at a fair price.

   Mike HennessyPittsburgh, PA

1. 
   kalman | May 29, 2007 02:07am | #7

   Thanks Mike.  I will relay this to my daughter who ultimately have to decide which way to go.  My gut is usually to not skimp and use the best product. In the long run  it is  always the cheapest.  I have already spoken to a local tile installer and he agrees with you.  Thanks for your time and concern.   Kal

3. 
   achome | May 18, 2007 08:13pm | #3

   I second the suggestion on Ditra, especially on a concrete slab.  Go to the Schluter website.  Also check out the John Bridge tile forum; he also has a Great book on tile work at amazon.  Gave the book to the builder cause I wanted his directions closely folowed.  He kept the book..I was bummed.  Never to be seen again.  Check with Schluter to see if you can put the ditra on the tile.  As another knots posting said, you may have height issues on your thresholds, door bottoms etc.  May be difficult to pull up the old tiles.

   We did all of our tile work with Ditra on the floors and Schluter Kerdi in the showers.  Significantly more bucks to install the ditra.  Probably can be DIY'd if you follow the directions.  The floors were not concrete, but radiant and I did not want them to crack when subjected to changes in temperature.  Hi-tech stuff.  See fine homebuilding maybe 2 years ago..cover article.

   Johnny

1. 
   kalman | May 19, 2007 04:17am | #5

   Johnny,  I passed on the info to my daughter and am looking into the article in fhb. I knew I could count on the discussion group for help.  Thanks Kal