for those interested. The Mapei rep comments were: "The product is mixed in the pail and can not shade if mixed properly. The grout joints appear to be very deep in some areas while somewhat flush in others. This is an installation issue and not a result of product performance." and "The outcome one sees in the photos is not typical of the Opticolor grout. Applying Opticolor results in color consistent grout with flush grout joints. The grout issue you have is an installation issue and not a product issue.".. No suggestions for remediation, but he gave me names of three installers. I hope they will be willing to come and finish the job..

It could be a number of reasons why but my take would be the grout wasent mixed and or floated correctly. You need certain size space between tiles in order to determain if sanded or unsanded needs to be used. Looks like sanded grout to me. Get a grout saw and get in there get the remaining out and regrout it and let the grout dry to what ever the back of the grout bag states. It can not stay like that, water will collect, contractor is wrong. You might want to ask the contractor what was used for a water proof membrane under tile and how the substrate was preformed as 99% of cracked grout is from movment in the floor.

One of my siblings started that profile, I don't keep tabs on them. I started mine roughly 4 yrs ago under a different name. Nice try though. Kelly (cx) gives good info but even he makes mistakes and we've gone behind him to fix them. (We live in the same town) If I'm correct, he does Schluter showers..or is it Kerdi? We don't deal with those products so I'm not sure. He's a nice man and he'll talk your ear off. Last time I saw him, he came in inquiring about what type of adhesive to use for a product. That was years ago. And yes pippabean, I only recommend standard sanded grout for the wet floor of the shower. We mainly deal with traditional mortar beds in the shower, these beds have pan liners in them. The pan liner is there to collect any water that escapes the drain into the mortar bad. A standard sanded grout is needed to allow this moisture to escape properly. Upgraded grouts like epoxy and single component grouts do not allow moisture or gasses to pass through, trapping the moisture in the pan liner. --Now, hindsight is foresight and I should have asked if the OP knew what type of bed was installed. (most homeowners wont know) But then again, I will still only recommend sanded grout. We've been down that road and I sure as heck don't want the OP, or anyone else, to go down that road. That could easily be a $1000+ repair. We've been in business since 1971. We've made mistakes and we've learned from them. My goal on this site is to offer advise and hopefully steer that consumer away from a costly mistake. In the end, it's their choice.

There's only one right answer: silicone at the intersection of two planes. And if your tile guy doesn't know this, he's incompetent.