I work over hotmops all the time. You should run your poly or felt all the
way to the pan floor. It seems from the pic and your description the
poly only overlaps 1/2". The minimum is 3" over lap and more is better.
Take a look in our liberry and read up on Shower Conustruction
. This will help you understand why and how all this
works. Must be in cali eh, were one of the only states using hotmops