I had antique white caulk along that entire countertop-wall juncture behind the faucet & sink, behind the stove, all around the kitchen - 4 years and counting, and no problems at all. And I am not a neat cook or good housewife. The newer all-silicone caulk is really tough stuff, it doesn't crack like the older acrylic blends, and as was already mentioned, unless you really leave puddles of grime and water sitting for weeks, there shouldn't be any trouble. Every grout manufacturer makes silicone caulk that matches their grout exactly, your tilesetter will order it along with the grout & tile. On the other hand, if you are in love with the idea of a 4" backsplash and think it will be of use to you, don't let your guys talk you out of it. I myself always found that little ledge annoying because it was too small to perch anything on it but big enough to catch all the dust and dirt -- but it's your kitchen and your decision. There's no real right or wrong here other than the fleeting whims of fashion, which will change again soon enough. Enjoy!

I've been googling madly about silicone and this is what I've found. They are not all created equal and some of the cheap ones attract dirt. I think that's what's happened here. In defense of the fabricator, I think they haven't installed much white quartz and I don't think you'd notice the grimy looking silicone on granite. Also, I wonder whether they did an inadequate job of cleaning the surface before they applied the silicone. Maybe it looks dirty because there's some dirt in there? Do I have any recourse here? Should the fabricator help me out? It doesn't seem reasonable that 3 months out, the joint looks bad. I think at the very least, I should call the fabricator who installed my quartz and let them know that they need to use a higher quality silicone for white quartz installations. How do I find out which silicone is best when I replace the existing caulk? I'm worried about the silicone that's down in the joint that I won't be able to reach. I think they put a bead of silicone on the edge of the counter near the wall and then put the backsplash piece on top. That silicone will be impossible to get out. If I cover it with white silicone, will it look OK? Is white silicone opaque? I'm upset about this because one of the big issues I had with my old kitchen was that no matter how clean I kept it, it never looked clean (thanks to the 1970s color scheme). Now I have a new kitchen with a 15 foot long seam that looks grimy no matter what I do. Ugh.

You want to caulk that joint, not grout it. Any change of plane, like counter to backsplash, counter to cabinets, etc. should be caulked to seal it from moisture. Caulk should remain flexible, if there is any movement in either surface. Grout used there could crack over time and you lose your moisture seal. For our last two backsplashes, I used caulk that was color matched to the grout that we used. Since our grout was sanded in both instances, we got the sanded version of the caulk. This was available at the tile store that we got the grout from. When it is all done, you should not easily notice the difference between the caulk and the grout.

So, I talked to a tile guy today. He has good reviews on Angie's List and seems like reasonable prices. He said he would not want to take out several rows from the bottom because it would risk damaging the counter and the rest of the tile. He said the only option would be to redo the entire backsplash, which we don't have enough leftover tile for and honestly I don't want to spend the money on. He suggested either a border of some sort to cover the imperfections, or recaulking and trying to use the caulk to make it look better. I suggested maybe he just entirely redo the area behind the sink (there is a wide window there so it doesn't go very high), and then recaulking or adding a border everywhere else. I'm waiting for him to send an example photo of what the border might look like.