Flooring Tile - cracked tiles and mortar question

Hi,

I tiled my bathroom and entry way using the wrong thin set I guess?? Now I have hairline cracks where the concrete was cracked under the tile. First, I should ask if I used the wrong mortar. It was Kera Flor made by Mapei and I bought it from Lowes. It was the cheapest mortar, but was recommended by the person who taught me how to tile. He use to be a pro tiler years ago so he didn't know the newer products. Anyway, did I use the wrong Mortar? I told my friend that the tiles cracked and he said to take up the old cracked tile and use DAP to put down my new tile spreading the DAP in S shapes so the DAP will stick. What do you think?

Second Question,
I tiled my kitchen using Ultra Flex2 (polymer-modified one-step motar) also made by Mapei and was bought at lowes as well. I tiled it BEFORE my other tile cracked in the entry way and bathroom. The kitchen had wider and deeper cracks then the bathroom and entryway, so I was told to use this Ultra Flex 2 by the person at Lowes. She said "no need to patch the concrete because the Ultra Flex 2 is patch and mortar, all in one." So far no cracks:) am I to assume that there will be no cracks in my kitchen because it didn't crack the same time as my other two rooms cracked? If my house were to shift, the whole house would shift, not just one side of the house right? My bathroom and entryway are on the left side of my house and the kitchen is on the right.

I am hoping that the woman at Lowes knew what she was talking about and Ultra Flex 2 was the right mortar to use and I didn't have to repair the concrete first.


Last question,
I still have to tile my mothers house. Depending on what y'all say, should I just use Ultra Flex 2 ($30.00) in her whole house or could I use Kera Flor ($5.00) in the rooms where there are no cracks and the Ultra Flex 2 in rooms that have cracks in the concrete subfloor?

Thank you,
Darla (textucker)

Did you use mortar (a dry powder that comes in a bag to which you mix water) or mastic (a pre-mixed material that comes in a bucket ready-to-use without any mixing)?

I used the kind that you mix with water. I noticed yesterday that my kitchen tile is indeed cracked. I called Lowes and talked to a person who lays tile and told him what that woman told me. He told me that the woman no longer worked for lowes, great. She gave me a bum answer. Now I have cracked tile in all my areas. Needless to say, I am not a happy person.

The man I talked to said that I needed this "membrane" stuff that you put on the crack?? I don't understand what it is. He said it cost $64.00, wow.

Do you know what a membrane is?

Thanks,
Darla

see www.noblecompany.com look at Nobleseal CIS.

I looked at Nobleseal CIS and it cost quite a bit, $9.90 a square foot. I have about 30 tiles cracked so does that mean I need 30 feet of Nobleseal CIS?

Do they sale that in any store?

Is there something else I could use that would work just as good but cheaper? $300.00 wow!!

Thanks
textucker