Guys or gals,I am an amateur! I am in the process of installing a 5 by 5 shower with two seats.My questions, 1) do I have to put the PVC over the seats? 2) do I have to pitch the pvc pan so that the water that seeps through the mortar bed (tile & thinset) is directed towards the drain? or will the water that seeps through be too immaterial to worry about 3)if I need to pitch the pvc, how do I do it? with the backer board? or someother method?Thanks so muchDazed and confused