I recently had a porcelin tile floor installed in my kitchen. Over the next couple of weeks I noticed that I was tripping on the grout lines. After inspection of the grout lines I felt they needed to be filled in a bit more. I contacted the installer and asked if this could be done and I was told no - not unless they remove the existing grout and start over. The installer used a non sanded grout on a grout line of 1/16 to 1/8 inch space. It is not sealed. Is is true that he would have to chisel out the existing grout and start over? Please advise.

In some cases you can level the grout lines out with level best but it wont always turn out the same color as the original grout. So you may have to stain the grout or level best after applying.

I assume your tile edges are sharp and you can feel them with your hand or bare feet? He wiped the grout too soon when he applied it. It needs to sit after the first scraping with the float. The cleaning of the tile with a wet sponge removed to much of the material which is why your seeing this issue.

If he used non-sanded grout on the floor with that size space between the tiles you’re going to have grout failure anyway. You need to remove the old and put in new. The sand in the material provides the bulk that is needed to fill the gaps and strengthen the material. There are tools that can be purchased that will remove the old grout fairly easy. Its a dusty job but one that can be done. If the grout is new, it will come up faster as its still sort of soft. Old grout becomes much harder as it ages and becomes more difficult to remove.
If this is a new install the contractor should come back and fix it for you.

Thank you for your responses. I appreciate your help and suggestions. KLS