My shower leaks when water is splashed onto the trim plate around the water dial. I assume there is some sort of gasket that needs to be replaced. I do not know what any of these parts are called.
Please enlighten me as to the name of the parts I'll be dealing with, and any information that may be helpful in fixing this problem.
To be clear, I can run the shower for a solid hour when nobody is in there with no leaking. Once someone splashes water onto the handle or spigot, water can be seen leaking around the pipe (witnessed through access panel).
Best Answer
That is a Moen brand shower valve and trim. The escutcheon (trim plate) comes with a foam gasket surrounding the hole. When you push the trim plate over the stainless steel stop tube (cartridge cover), or when you push the stop tube through the escutcheon, the foam seals around it. The inside of the stop tube is leak free because it slides down over o-rings on the cartridge.
Italics indicate "official" part name.
You need a new escutcheon.
Can't comment on your "spigot" because we can't see it in your picture.
NOTE: this assembly is designed to resist incidental splashing. Prolonged exposure to high-pressure water douching will leak even with brand new parts. I have found them sealed up with caulking, which will work, but makes it a bitch to repair and therefore I charge more $$.