I am finishing a shower pan. Do I install the durock first and let the mortar push against there backerboard or do I install the shower pan and then install the durock on top of the shower pan mortar bed?

From what we have seen:

1. Preslope for shower pan liner.
2. Shower pan liner
3. wall moisture barrier and tile backing
4. Tile setting bed over shower pan liner

* make sure to use gravel or something like that before around the drain weep holes before packing in the setting bed over the shower pan liner.

Www.WestCoastShowerpans.com

Hmmmm... this is always debatable!

1) preslope for shower pan liner
2) install tar paper in between preslope mortar and vinyl pan
3) moisture barrier on walls
4) pour pan
5) install wallboard to within 1/2" of poured floor keeping screws at or above the level of the threshold.
6) Fill 1/2" gap with thinset mortar

And as Westcoast said, "* make sure to use gravel or something like that before around the drain weep holes before packing in the setting bed over the shower pan liner."... VERY IMPORTANT HERE!!

In my experience, there is less chance of the concrete board wicking water up from the pan if it isn't set directly into the pan... *SHRUGS*.

See attached image.

Back to you...

Mark