I am working on installing on a shower in my basement. I bought a Sioux Chief no caulk 'slip' drain. I have the roughed in drain pipe sticking up out of the concrete floor. I need to know how high the drain pipe needs to sit in the drian. Right now it is flush with the shower floor, I know this is too high but before I cut it I want some advice. If I cut it too short I am SOL because the roughed in drain pipe is set in concrete. HELP PLEASE!! :)