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.

They sell grout saws at home centers. Maybe $5? Takes a bit of time but they work. A mechanical tool, like a dental pik, has been mentioned by some as well. Helps pull out the pieces. Caulk next time. You can get color and texture matched caulk. Mongo

I recently tiled and grouted a tub surround. This was my first tiling project (part of a complete bathroom renovation) and I used Laticrete SpectraLock epoxy grout because of its stain resistance and low maintenance. The grout lines are 1/8 inch. I've never used regular (non-epoxy) grout, so I can't compare the two. But the SpectraLock was not difficult to use - just follow the directions, especially regarding time. I bought the SpectraLock from Lowes in mini plastic buckets. Each bucket includes the two epoxy components, a pair of latex gloves, and a sponge. The color component - colored sand - is sold separately in one-quart milk cartons. I have a two-year-old son and four-year-old daughter, so frequent interruptions are the norm. A good tip I read on John Bridge's forum is that mixed epoxy grout can be saved for later use by placing it in a zip-lock bag and freezing it. When doing this, place the grout-to-be-stored in the freezer immediately after mixing it. From my experience, if you mix the grout, use some and then decide to store the remaining grout, chances are that it will have cured too much in the bucket and will not spread smoothly after the freeze/thaw cycle. When using the frozen grout, I simply cut off what I needed with a hammer and cold chisel and kneaded it to a smooth consistency after it warmed and softened. I used grout that had been frozen for 5 days. Regarding caulking: Laticrete makes color-matching 100% silicone caulking sold under the Latisil brand. However, Lowes does not sell this. Instead, they sell an acrylic caulking from Laticrete. You can buy Latisil on-line or at tile suppliers who sell Laticrete products (see Laticrete's website for both). Latisil is more expensive and more difficult to use than acrylic or latex caulking, but far superior.

I hate contractors and their incompetent subs with a passion! We've had so many "do overs" on this reno it's not funny. How some of these people can stay in business is beyond me. And where's the pride of a job well done? Seems non-existent. I don't know how many times I specified caulk between the countertop and backsplash and what do you think the tile guy used. So know we wait for the platinum caulk to come in and then he has to come back and chip out the grout before he caulks. And just like your guy he wanted to caulk over the grout. I flat out said no, this is the way it has to be. I feel like I need to babysit these people which is so not what hiring a GC meant to me. I won't even bore you with how the plumber screwed up. It's just been one thing after another.