Firstly you need to be sure its the silicone that is the reason for the leak, it may be the waste trap in the shower tray.
Run water down the waste to see if you get water in the bedroom.
If no then you need to cut out the silicone with a stanley knife and clean the area before re siliconing, ensure that the area is total dry before you apply the silicone tho.
steve
February 2009