Just bought a home and have discovered that our shower drain wobbles about 1/4" back and forth. This is just enough that it slowly pulls any caulk we apply away from the shower floor, allowing the water to seep around the outside of the pipe. We know nothing about plumbing and all our searches tell us we need to remove the whole shower, which seems a bit overboard!

We are newbies, so if anyone has a good detailed explanation on how to grout/caulk/ or otherwise attach this pipe so it doesn't move, it would be much appreciated.

Oh yes, the house is pier and beam and all plumping underneath the house is apparently free-standing. For example, I can slightly shake the entire pipe that runs from the hot water heater to he shower. Not sure if that is normal either.