I already have a copper shower pan installed. I need to know do I just put decks mud in, or should I put in a pre-slope layer, then a vinyl liner, then final deck mud. In know a vinyl liner alone would have been best, but the copper is already there.

I would greatly appreciate any advice with this problem.

Hi Martcj:

Is this a new copper pan.. If it is all you need to do is to test the copper pan by plugging the drain with a test ball (see picture... sold at plumbing supply house) and then fill the pan with water to the level of the threshold and then hold that test overnight (up to 24 hours) to be sure there are no leaks associated with the copper pan or the drain connection to it.

Then after test, just need to pour the mud floor (2-3") and pitch that to the drain at about 1/4" per foot of slope. Laticrete sells a superior thick floor mud for shower pans... extermely strong. Some people add a layer of chicken wire into the mud bed... up to you on this.

If this is an old pan then I would still perform the pan test (using water).. if there is any question about pan lasting I would remove the copper pan and install a new vinyl pan. If rip out copper pan and install vinyl membrane I would prepitch about 1" of mud to drain BEFORE installling the membrane (tar paper between 1" pitched mud and membrane to reduce abrasions to membrane)... then after vinyl pan installed I would wait 12 hours for membrane adhesives to dry, and then I would water test the pan as described above for up to 24 hours... then pour the pan as described above.

I would not install a vinyl liner inside a concrete pan... ;) I just don't see how you could make a useful/waterproof connection between the copper pan drain and the new vinyl membrane... that make sense?

NO screws go below the threshold for anything... ok??

Here is a link you may find useful... (click on link)

How to Build a Shower Pan (http://www.hoagy.org/house/HowToBuildShowerPan.html)

Let us know if you have more questions...

MARK