Yes what Clay Aragon is saying I second all he said. It is tile installers job to qualify floor condition prior to install and part of his job to accept or reject tile prior to job completion.

This is a common problem with longer length plank tile (more than 24"). The longer the tiles, the more prone they are to bowing in the middle. When tiles are arranged at random to look like wood, any tiles that are close to a 50% layout will show a bit of lipping usually. Many manufacturers will specify how the tiles should be arranged to avoid the lipping. We have 6x36" plank tiles in our house and we chose to disregard the manufacturer's advice and lay them randomly, knowing that lipping was a possibility. The other option (per the manufacturer) was laying them in a 1/3 pattern, which didn't give the wood loom we wanted. We were lucky to only have a few noticeable areas in a very large space and we have learned to live with them. Your tile color and grout look great. Is this in a place that can be covered by furniture or a rug? Best of luck to you!

Thank you all so very much for your immediate replies! Much appreciated. Some of tiles were indeed warped. The tiler showed me this by laying two tiles on top of each other (face to face) and I could see how they came together towards the centre but slightly apart towards the edges (picture attached). I was also told by the guy at the local hardware store that such long tiles are often "crowned" due to the high temperature they have to endure during the manufacturing process. I just wish the tile place where I purchased them from had at least warned me about such problem. Thank you all once again

Like everybody else, I agree that the tiler should have informed you of the problem immediately rather than continuing on to the point where the installation is a fait accompli--leaving you with little practical recourse. I can't tell from your pics what style your house is,but if it's old world or rustic I think imperfections go with the whole vibe and add a handmade type of character. But even if your house is modern you will find that you stop noticing all the little imperfections which initially draw your scrutiny right after installation.

Thank you Mcbriec. The house is indeed rustic. I appreciate your comment and u agree with what you had to say about the little imperfections. Infact, a week later and I'm already over it :). Thanks again.

If misery loves company I had he same experience in our bathroom remodel. HUGE disappointment to see uneven tiles and lippage everywhere- it's all I see when I look at my new bathroom- and we paid in full, done deal..Live and learn I hope!

Tile Council of America governs tile and installation standards. They explain how and why large format tiles warp. There is no question that it occurs. Secondly, they acknowledge that from a design standpoint, longer, rectangular tile and stone is VERY POPULAR.

You might plan on more waste, and discard the warped ones. Blaming a contractor for design and manufacturing issues doesn't seem fair, although the leveling spacers do a great job of minimizing edges that are not uniform.

Planning for more waste is a good thing. However, I have seen "good installers" work and they will use a very large level on the floor as they are setting the tiles and check it as they go as well. They know that until everything is dry that there can be some settling and shifting even if the sub-floor had a "leveling compound" added before any tile installation started. The issue is going to come up more in the next year or so as the new LARGE FORMAT TILES become more common. A good installation will have the following:

1) as level of a sub-floor as possible or NEW LEVELING material poured before tiles are installed

2) a quality, consistent tile product from a credible manufacture

3) tile setters / installers who pay attention to matching tile heights as they are installing.... using a large level and going "slower" for large tiles to "set up".