The best way to start is by holding a few extra pieces side by side and comparing the two. It is not un common for longer pieces of tile to have uneven spots but it seems your tile setter should have picked up on this and a discussion could have been on how to best work thru it rather than jus install and grout it

They recommend a 1/3 off set for the longer tiles, which would eliminate this problem. It could also be unevenness in your subfloor.

Virtually all porcelain/ceramic tiles have some degree of what I call cupping (there may be another more appropriate industry term for it) that is created in the "baking" process. This cupping can be found in budget tiles all the way up to extremely expensive tile. The unevenness you have is called lippage and is created by the high portion of one tile (generally toward the center) being laid against the lowest portion of another tile (generally at one of the ends/corners). It has become a problem in more recent years due to the trend in popularity of larger format tiles. It is most pronounced in patterns such as running bond (what you have) , herringbone and some of the staggered sized patterns. A 1/3 offset (or less) is recommended to minimize the effect. A good tilesetter can work some of the issues out, but not always. We have talked with many tile shops and we try to talk with the manufacturer's when ordering larger format tile, but we have never been able to get a manufacturer to tell us that they will guarantee that the tile is not cupped or allow us to return the order (prior to installation) if we check it and it is considered to be unworkable.

This could be due to the fact the manufacturer wants the product to look like hand scraped wood...perhaps. First and foremost, contact the manufacturer and have them look the goods and installation. The installer may be responsible, perhaps not. Don't pay him in full until you're satisfied!!

I don't mind that at all .it looks like natural wood to me.

I have the same tile installed (although it looks different from you photo). Maybe it was my grout color but my floors do appear more level. It took my installer a very long time to install (days) because this floor is so challenging to install.

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.

@graycat2....That's what I'm trying to convince myself into thinking. @cumminglj....your floor looks so much better! Your guy did a great job. I'm also having issues with the grout color now. It turned white and yesterday I made the tiler scrape it out and regrout it. I blamed him for now wiping the floor before grouting. A few hours later...it's white again :(( . Any suggestions please?

@ Jared....I wish he had done so too. He only mentioned it after I complained and 2 rooms had already been done by that time.

@ Carol...we did offset it. The tile is 90cm long and we offset it by 30cm. Thank God for that cos otherwise I'd have small hills in my house!

@ Deborah.... Thank you for taking your time into writing such a detailed reply.

@ srobertb... He never mentioned anything about it. I know I would have taken them back.

@ Gray & Walter... It's what my husband told me "well, it looks more like wood". So I'm trying to look at it that way.

I have had two natural wood floors done and it looks just like that .

The grout turning white is due to Efflorescence. I am curious what type of grout was used. Efflorescence usually occurs most often with a sanded grout. In the future anytime you get tile done make sure you use a better quality grout such as a epoxy or acrylic grout. This will save you a ton of headaches in the future. Epoxy and acrylic are non-porous grouts and will not stain as easily as sanded. They also do not have issues with efflorescence. Try scrubbing the grout with a wire brush and detergent. If that does not work you could look into some chemical cleaners on the market to try. Efflorescence is caused quite often from adding too much water when mixing the grout.

Old post from 2015.

Apply weight on the warped part immediately after laying the tile and the adhesive setting in. Try using Sand bags..

Hope this works..

@srobertb "This is 100% on him and he should repair and fix." easy there stud, how could a tiler "FIX" an baked bad ceramic plate ? He can't use ironing machine and flatten the tiles LOL. Only thing he could do is to tell in advance to homeowner what will go wrong, and to ask to do different pattern and mask the bent parts a bit with bigger spaces between rows (3-5mm for example) and by moving each new row 20cm ahead like i did on my last project

These are also bent, a lot more than his, but i managed to hide it more.

@hanif_chauhan "Apply weight on the warped part" that's not how ceramic tiles works buddy... they are baked on around 1,000 °C and you think only a weight can fix that ?

@gulullu sorry for "necroing" the topic, but bro "I just wish the tile place where I purchased them from had at least warned me about such problem" that's also not how market works... If they point out every bad tile they have, they would never sell you anything that way, and its in THEIR interest to sell you, as you might warn 2-3-5 customers not to buy there, but they will sell much more than you can warn, so its still their win. And usually they say "don't worry about that, your tiler will fix it" , which is BS, we CAN'T fix it, only mask/hide it a bit. You have less "bent" on more square like tiles tho, 45x45cm or 30x30 for example.