The vertical wall seams crack more readily because the house shifts and moves. Ive tried grouting only and going back to caulk with sanded grout caulk or silicon only after a crack develops, hoping in some cases it will not. Sometimes it does not crack. Some contractors caulk all seams as a matter of course, no callbacks, safer. I liked the idea of sanded grout caulk to match your grout color It has not held up for me in wet conditions, such as the top of the bathtub where the wall tile starts, etc. , definitely not along the shower floor where the wall tile starts. It has held up in other areas though, and looks nicer when it all ties in. I agree, mildew on silicon is unsightly. Every bathroom has different conditions, including ventilation, moisture, etc. Some people have to clean out and recaulk the silicon every year or two. Whether its allegedly mildewproof silicon or not.

I'll tell you... I had to replace caulking around a tub from the 70's. the prior owner had put latex caulk over top of it. That peeled right up. But everyone kept telling me to use a putty knife to loosen the old stuff and scrape away at it. I tried and tried and tried. I even got lift off and it just made the top layer gooey enough to scrape away. I tried scoring it with a razor first. I even bought one of those caulk remover tools (not worth it), I tried everything. I finally took out my dremel and made holes every 1/2" or so in the caulk line, then took a chisel and, Very Carefully, chipped the caulk out. It wasn't as easy as everyone said it would be. Notice how they always cut away when the home improvement shows are doing this. they don't want to show you all the swearing! Good luck, and bring your dremel.

Thanks for your responses. Millworkman, between the tiles on the wall around the bathtub controls and the tub, there is a space. I spoke with a guy at Lowes today who told me to fill the space with Type 1 tile adhesive before putting in the grout. There is a good chance that the space could be the source of a leak. The man at Lowe's also told me they did not have a product that would loosen the caulk. The scraping is difficult. Thank you, jfcwood. I am being as careful as I can, and we will have workmen here next week to fix another bathroom, and they did agree to advise we if necessary. Plumbing problems are expensive. Sammy

With the work being done a few weeks ago, there is nothing wrong with calling the installer who tiled and asking why grout was used in the changes of plan instead of caulk. Ask about the corner grout cracking. What if? Will remediation be offered? Caulking a shmear of caulk over a grout joint is not going to prevent the grout underneath from cracking if the grout is prone to cracking. Some corner grout never does crack. With your house being an "old 1060s", it may be nicely settled in. You may not have differential movement between the wall planes that leads to corner grout cracking. Grout sheds water. Caulk sheds water. Both are superficial things that "pretty up" tile installations. The real waterproofing should be behind the tile. Caulk needs some depth to it, if it's just a veneer over grout it may peel delaminate over time. Latex caulk versus silicone? Both will shed water fine, but 100% silicone will perform better in standing water than 100% latex. You'd be correct to make a phone call and to ask questions. And to get answers. Sometimes I'm of the mind that although best practices may not have been followed, second-best practices can still turn out fine. Meaning, you could leave the installed latex caulk until you have issues. You may never have issues. But if you do, then replace it. Same with the grout in the corners. Leave the grout in the corners until it cracks. Then replace it. When you talk to the installer, if he offers to come over and remove the grout and replace it with caulk? Sure, you could take him up on it. Or just get an assurance from him that if problems develop down the road, he'll swing by to make things right. It's best to get those assurances in writing. It's really what you feel most comfortable with. And how accommodating the installer is with regards to backing up his work.