I am a DIY'er and did a pretty significant bathroom remodel where I did all the tile work. On my shower, I used Laticrete Hydroban and durock for my walls. At all corners and at the tub flange, I used fiberglass tape embedded in thinset, sort of like your video. Much cheaper I imagine. The Schluter Band is water and vapor proof I believe. You will be using Redgard to achieve the same water management goal, so I don't believe you would need the Schluter product. All changes of material and planes will be covered with the fiberglass tape and thinset. All the fasteners will be covered with thinset. All valves are set with tape and thinset, or the product included with the valves. My valves came with a taping product that I thinset into place. Then everything is coated in the water management membrane such as Redgard or Laticrete. I filled in all small voids with thinset. I don't have a picture of the bottom of my shower pan and Durock, but I think I taped it with the fiberglass tape. It has been some time since I did this job. Below, is my thinset and taped cement board. True Confessions, I don't think I have enough fasteners, nor the right kind, in my wall, and I worry about this flaw in my shower. I had drywallers hang this for me when they did the rest of the room. I assumed they used the correct fasteners, but they didn't. They started out with galvanized nails, which I believe would have been ok, but I wanted screws, so they switched to the drywall screws. I had the Durock screws, but didn't give them to the workers, assuming they had their own. They didn't. So after they left and I saw the, I tried adding my Durock screws into the wall. I couldn't do it, I just wasn't strong enough. DH was out farming and wasn't available to drive more in for me. So I proceeded. My mistake, as I learned later the drywall screws deteriorate in cement board over time because of the alkaline conditions. I confessed to DH that the walls might fall down in a few years. He said, "well when they do, we'll just fix it." What a relief I felt, I no longer carried this burden of knowing that I flubbed up: Here is the bottom where the coating is onto the shower pan. It hard to see, but the pan and walls are totally sealed in the Hydroban. Click it open to see the bottom of the walls at the shower pan, where I taped a plastic sheeting to protect the pan. Be sure to follow the recommendations for thickness with your Redgard. This is Laticrete Hydroban: If you click the picture open you might be able to see the valves sealed with the Hydroban. This green tape is by 3M and is very strong used for taping concrete I believe. It was great to use to hold hanging tiles into place until the thinset cured. You will want this tape for your tiling job, I loved it:

Thanks, Bill. I talked to my contractor this morning and he said: 1. He used silicone at the corners of the sheet rock. He also said the reason he doesn't like to use caulk at the corners is that even though it is supposed to be the same color as the grout, it really isn't, plus the caulk will crack if the building moves just like grout cracks. I asked him about grout behind the caulk and he said he recommends keeping the bathroom dry by using a squeegie/towel where needed, particularly along the top of the tub. The grout looks so nice I guess I'll wait to see if it cracks. It probably will as the roof needs more work and I guess I'll caulk at that time. 2 and 3. There isn't grout at the tub line. It just looks like it as the grout is the same color as the empty space. (That's what I get for looking at it at night.) 4. OK 5. Tub reglazing was put last on the schedule so that it wouldn't get damaged during the other stages. I am going to have them cover all of the walls up to the tile line, and the floor, with plastic.

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.

I have learned something here. I did not know that the sanded caulk should be used for larger gaps and non-sanded for smaller. Any reason why? Second, a bad tile job was also done in a relative's kitchen. The tile guy grouted rather than caulked where the quartz countertop meets the backsplash. She refuses to have him back in her home. She asked me to help remove it with my dremel oscillating tool. I am reluctant to do so until it starts failing. Any hints on removal?