You can put the drain where ever you want as long as you slope to it. I usually figure a 1/4 inch per foot slope. so 4 ft would equal 1 inch.I'm building a tile shower but want to put the drain on the far side instead of in the center. To use a center drain means to notch, cut, or drill through 3 floor joists. I'd rather just let it drain to the far side, like a tub. Is this reasonable/possible and, if so, what is the necessary/suggested slope?