I think whoever installed the plumbing used CPVS and didn't even secure the shower head so it's loose. I don't want to open up the tiled wall so I'm going to spray some Great Stuff foam in the hole and use some kind of glue around the pipe. What would you recommend? I thought about grout but I think that would just crumble after a while. Maybe some sort of cement? I can cut around the pipe to add more room for any kind of adhesive/cement.