spacing of the tiles

I once saw hardly any space between tiles applied to the walls. Can I do that with my floors? What would be the negatives of having barely any grout lines? If I do need grout lines what is the recommended width, and how small can I go without any problems?

 

Rectified Porcelain or Natural Stone can be placed with what is called a zero grout line.. This is great because less grout is always nice, less worry of staining or getting it dirty.. If your tile is not one of the above the smallest grout line you should use would be a 1/8" groutline this usually works with even the lesser quality tiles. I have had customers use a 1/16" grout line but only with high quality well constructed more even tiles.
Rectified - means it has been cut to size AFTER coming out of the kiln that is why it can be calibrated for exact
specifications. Most tile is first shaped than baked afterwards so it often has a 1/16" or more difference between tile in the same box, Which is cause for larger GROUT Lines.

 

You need grout between the tiles. Spills and whatever will collect in the space between the tiles (there will always be space) making it a breading grout for mold and all sorts of funky stuff. The size grout joint you need will be dependent upon the tile you use.