Originally Posted by davidmash

I put something else down when I did my floor. I had some hair line cracks in the slab and I went to a tile only specialty place. They sold me a 'rubber' type thing that had a thin layer of fabric on the back. I rolled out some special contact cement (clear like water) that reacted with the rubber and laid it out n the crack. I was told it would allow a little movement (settling) and not crack the tile. So far the tile has been down almost 6 years and no cracks. I did lay slate by the way and they are 16x16.





The membrane was quite thin as I recall, maybe the thickness of a credit card or a credit card and a half. It's the red stuff on the bottom of the first picture.