The most important part of the whole shower is the pan liner.  This is the part of the shower that is acutlay waterproof, and the last line of defense against the water.  Its crucial that the pan be isntalled correctly, without any holes in it.  The pan gets installed on top of a ‘deck mud’ pre-slope.  This means that the liner, when correctly installed will have a slight slope to it so that all of the water that collects in the pan, flows down into the weep holes in the drain.  Since the pan is so cruical, its important to test it by filling it with water leaving it overnight and making sure it doesn’t leak. 

Thats what I’m doing here, I’ve installed the liner over the pre-slope, folded and sealed the corners, and added extra reinforcement around the drain.  I’ve then stapled the upper edge of the ban to the 2×10 blocking I installed, and have filled it with water.   I’ve also drawn a line at the height of the water, so that I can tell if any has leaked out.  Hopefully tommorw morning the water will be at the same level, and teh ceiling below will be dry!