OK mylegs... here we go.
See that picture at bottom left... that is the drain you will need for a vinyl membrane type shower pan (if going with copper pan, let me know because instructions change quite a bit... but you said membrane, so... ).
You will need to install the shower drain in the following manner:
I drill two holes in my floor for a shower drain like this... one large enough to fit pipe and drain fitting through the entire floor (3" or so) and the other is drilled through only 1 layer of flooring (this hole is exactly the width of the shower drain...about 6" hole.. but measure drain... I use a rotozip tool to make this hole). Then the bottom of drain sits inside this large hole, but is supported by the floor that has not been cut through underneath
. This usually leaves the base of the drain flush with the wood floor... OK so far?
Now, set the drain in place and measure to the ptrap or coupling underneath, cut pipe, and prime/cement the drain in place. Now, the guys installing the membrane should pitch that membrane to the drain using concrete to about 1/2" to 1" inch at outer walls to 0 inches at center drain...AND THEN they should install the membrane to the drain and bolt the top 1/2 of drain assembly together for you.
If they don't then keep reading...
Now, you will need to push down on membrane over the drain which will leave an indent on membrane... trace that indent around the inside of the drain and bolts... STAY INSIDE THE BOLTS... then I install the bolts under membrane... push down on membrane again and make micro cut on top of the bolts... I remove the bolts... install adhesive between bottom drain and membrane and then install the top part of drain.. again adhesive between top half of drain and membrane... and push bolts through microholes previously cut... keep it tight... and bolt down top drain. That should do it.
Then after membrane installed... I plug the new drain (remove strainer) with a CHERNE test ball (see pic. #2... test ball pumps up with a bicycle pump)... fill shower pan with water to within 1/2" of top of threshold...MAKE MARKS all around the membrane at water line...go away for 24 hours and when come back, should be at approximately same spot as was before you left (see line...you can lose 1/16" or so due to eveporation.. but no more)... Check everywhere for any moisture escaping... THIS IS YOUR LAST CHANCE... so check good.
Also note that depending on your shower pan size you may need to order a taller strainer
assembly for your shower drain assembly... I order this for all my shower pans... ANY PLUMBING SUPPLY HOUSE SHOULD BE ABLE TO ORDER taller strainer for you... IF you buy drain from them to begin with... WHY do I do that...?
I do it so I can pour a bit thicker floor... especially as I get to 4 foot and 5 foot shower pans... regular strainers are not deep/tall enough to allow much pan thickness at that size... so never bad idea.. but up to you.
Last thing... WEEP holes around the drain... you will see them.. weep holes and channels built right into drain... These require that small (1/2") smooth rocks and pebbles be laid around drain so that any water that gets under concrete floor of pan will drain back to and down into the drain by gravity (why they should pitch your membrane to drain before installing the membrane).
Then all is ready to install concrete. That should do it. Any questions, let me know OK? I will also post an informative shower pan site (thanks Ballengerb1)... review this so you are sure your guys do similar How to Build a Shower Pan
Good luck. Keep us posted.