I'm installing a neo-angle shower kit over a plywood sub-floor. The instructions state to use mortar or plaster to level the base. Is the correct way to lay the mortar bed directly on the plywood or use a non-permeable membrane like tar paper or 6 mil plastic on top of the plywood first? No where in the instructions does it mention to fasten the base to the framing, which I'm assuming is because of the potential of cracking the base if it flexes. So all the rigidity of the base is relying on the mortar leveling bed, that's why I'm not sure about compromising any bond between the mortar and plywood, but also not sure about laying a mortar directly on the plywood and having it absorb the moisture.
Also on one of the long sides of the shower base I'll have to shim it 1/2" to get level, the other long side is level as is. So on the front of the base I'll have a tapered gap with the sub-floor from 1/2" to 0". The finish flooring is 1/8" thick, so how is the gap along the front of the shower base closed, by feathering in floor level compound or is there a better way?
Also on one of the long sides of the shower base I'll have to shim it 1/2" to get level, the other long side is level as is. So on the front of the base I'll have a tapered gap with the sub-floor from 1/2" to 0". The finish flooring is 1/8" thick, so how is the gap along the front of the shower base closed, by feathering in floor level compound or is there a better way?