The caulking in the shower should be 100% silicone.

Geoffrey, I know you're responding to Dianne333 but I'm interested in your general opinion and/or that of other knowledgeable people

Should tile in the shower be caulked and not grouted? And only caulked with 100% silicone?

Trying to understand the differences between caulk and grout and when it's best/necessary to use either.

Thanks a lot.

I think all caulk in a shower will mold over time unless you wipe it down after each shower. I know the standard practice is to caulk all changes in plane but John Bridge says he grouts the inside corners of a shower, I'm assuming because grout doesn't mildew the way caulk can? He says he uses screws (not nails) to secure the wood underneath so it prevents or limits any grout cracking. If grout does crack it doesn't seem to be a problem (except from looks) if the shower was waterproofed properly. Always so many differing opinions.