Thanks for the info. The install was over a concrete slab. It was rectified tile too. I did check the lippage and it is definitely not 1/8" out of level. It's probably between 1/16 and 1/8 in the worst spots. Most others are much less than that when I actually measured. . I didn't expect it to be such a small difference, but the small grout times make it more obvious. We will try to regrout some of the areas and see if that helps. Our installer is going to come back to fix something else related to a different job. There is one area of lippage that's right near our refrigerator that's probably the worst one again, between 1/16 and 1/8. We may have him redo that one since it's in a very noticeable area. Maybe we should have gone with a slightly larger grout line. Well, what's done is done. Honestly it still looks nice though, I just wanted to make sure I'm not being too picky.

Bear in mind that 1/8" is the "break point" about sanded vs unsanded grout. Either will work, but sanded is preferred as it fills better and shrinks less. Personally, I like "prism" from Home Depot as it fills from a sixteenth to a half inch. Traditionally, you rack up 5 or 10 tiles on edge and measure any variation. That variation should be multiplied by three for the optimal grout width. 1/8" variation means 3/8" grout line.....

Rectified is more expensive. "Unlike your typical factory-edged tile, rectified tile has been cut to size after the firing process. This process creates a precise, 90 degree angle edge and, as a result, can be laid with a tighter grout joint than unrectified tile (as small as 1/16ÂÂ). If youÂfre wanting a smooth, sophisticated and continuous look on your floor or walls, choose rectified tile." Is it better? Depends. Do you need it? Depends. You want for your floor? How long are you going to live in house? You have to live with it! You have to weigh what you really want and what is important to you and how much do you want to spend. PEI 4 or better is a start. I believe a good tile should be above $3 sf. I could name some tile companies, but I don't want to sound like an advertisement: I do not work for them/I only like their quality of tile: and they will cost more, but that is the tile I would want in my house! Marazzi USA, and most all Italian made tile! Happy Floors Tiles are mostly made in Italy. If you like, look them up on the web. I believe: yes: you get what you pay for. Although, I believe there is tile out there too expensive for what you get. Do your homework. My honest opinion: I would only put travertine or slate in my home. The owner of where I work has only travertine on the floors that has been down for over 10 years and looks great. Her house has all travertine and slate on the floors for 10+ years and she has tons of kids in and out of her house daily! Two great things about travertine and slate: you don't slip and the travertine material absorbs sound vs. tile. (Only my first choice for flooring)

Your tiles are 2 foot by 4 foot?! Never heard of such a large tile. Anyway...thinner grout lines usually use unsanded grout. It fills the small joints better. As far as the width, the manufacturer recommendation is usually based on whether a tile is rectified (cut after baking for straight edges) or not and what they feel will allow for the smoothest floor. All tiles will have some sort of curve to them. It’s inevitable. The larger the tile, the larger the difference usually is in height from the middle of he tile to the edge. Put two tiles face to face and lay them down on a flat surface. You’ll likely see a gap between the ends. The larger the gap, the larger the grout lines should be to help mitigate the disparity. Can a good installer get small grout lines on even so-so tiles, yes. But it takes lots of sub floor prep and money. Being you’re laying a grid pattern means the high point is next to the other tiles high point so you are far less likely to have issues than one who lays the edge of one tile against the middle of another. Then you could have a lot of lippage and the floor could resemble a basket weave if not done properly.