Finally--finished backsplash...and advice
My backsplash was completed yesterday. It looks so much nicer in person. It was certainly not trouble-free along the way. At the beginning of the install, I noticed the thinset had a gray tone to it and had watched enough glass video installs to know it should have been whiter. I asked the installer if it was the correct thinset and he said he told his distributor he was doing a glass job and that is what they gave him. He deals with a very reputable distribution center. Knowing it should have been whiter, I checked out the bag and did not see the word "glass" on it. I called Mapei and they said it was the incorrect product. The installer stopped and called his distributor, and sure enough, he was told he was given the wrong bag. Fortunately, I think only about 8 sq. ft. had been installed.
My installer is one of the best and is often called to remove and repair other's mistakes. My advice is to check the thinset and grout (as we know from other's experiences here), regardless of the installer. The major companies like Mapei have a technical person that answers a phone right away and will know if it is the best product for the job. I once read that you should become the expert in your product since there are so many different types of materials, it may be new even to a seasoned and quality installer.