We recently moved into a new house. Both of our showers leak, but only when a person is in them. They both take about 3 minutes to start leaking. The ceiling is opened below both leaks. We have redone the caulking and tested the outside of the shower by pouring water on to the floor and nothing seems to be leaking when that occurs, so it seems to be coming from inside the shower. The handles have all been checked and seem fine. Our guy can't figure it out and says the pipes seem fine...any help would be appreciated! One is a stand up shower and one is a full tub. The full tub leak continues to leak for about 30 seconds even after the shower is turned off.