I installed porcelain tiles 13x13 in my entrance way about 6x7 area. I used smooth grout about 1/8 grout line. the grout keeps flaking in some areas. I redid it twice with the same results. I hasitate to scrape the lines deeply because I already stratched a tile doing that. Need help. Thank you

 

By "smooth", do you mean unsanded. If so, that is a mistake you will need to rectify by removal and replacement.

If you have sanded grout, then your problem may be that you used too much water when grouting. You should (1) mix the grout to a thick consistency, (2) never add more water after the initial mixing, and (3) make sure that the grout does not get any wetter when you use a sponge to clean up. I suspect that you may have wiped up with a wet sponge that got the grout wet. Your sponge needs to be just very barely damp.

If this is your problem, then you should remove at least 1/8" of the grout with a grout saw and regrout. To avoid scratching the tile, be very careful and very patient. With only a 6x7 area and large tiles, this should be a project that you can complete in less than a lifetime.

Good luck.