Recently found a leak in our ceiling and was able to trace it to the drain in the upstairs shower. The drain in the shower is a Caspers 101-P. My first suspicion is that the leak is coming from where the top of the drain flange meets the shower opening. There appears to be a very small gap there where I think water can get through. My question is this type of drain threaded or glued? If it is glued, then it appears that the whole shower has to come out, but if it is threaded, then maybe just the Caspers drain can be pulled and replaced. Any ideas or help would greatly be appreciated.