Flooring Over Concrete in a Kitchen

Q: I have a long thin crack in my cement slab kitchen floor. The crack is about 1/4 of an inch, but is about 12 feet long. I have tried ceramic tile, but it cracked when a professional did it and when my son and I tried to repair the section. Someone told me that laminate floors would have no problem when used with this type of problem. Also, they suggested I use a padded underlayment like the quiet walk/warmth walk. They said this type of floor is guaranteed by the Shaw company (which is the one I liked due to the 25 year warranty and the style I found). Is this true or is someone ‘pulling my leg”. Thank you .
Dianna
A: Before we dig too deeply into your option with the Shaw laminate, let’s talk about the subfloor and why the tiles you had installed cracked.
With any cracks in the subfloor, it is best to ensure that they are filled before installing any new flooring. Though this is not the precise cause of your tile cracking, it does show that movement is occurring in the concrete, which is normal, and when this movement occurs it is common for tile or stone installed over concrete to crack if an uncoupling layer is not installed. When the concrete moves, this movement telegraphs up through the tile or stone flooring. Stone/tile is not built to handle this movement with out cracking eventually occurring, this means that you need a shock-absorber of forms to remove this in-plane movement, which is why high-end stone or tile installs over concrete include uncoupling layers, so that this movement is absorbed without destroying the floor.
If you wish to install a new laminate floor, I would highly suggest testing your concrete’s moisture content, if it is too high, you may need to seal the concrete after repairing the crack. This means removing all of the current tile, then working on the subfloor. Repairing this crack is important if you intend to install a floating floor, such as Shaw laminate. After repairing, make sure the compound you use properly cures, then you can install the Shaw laminate.
You must install a vapor barrier and tape all of the seams, then install your underlayment (such as the quiet walk or 6mm cork), then install the flooring. No leg pulling is going on, but a few details as to the work needed are important. The reason why you will want to go through this work is to ensure the 25 year warranty remains intact, if you skip any of these steps, that rather nice warranty will be voided.