I have framed in a set-in deck off a second floor master bedroom (the deck floor is also the ceiling of the living room below). When originally built, the deck was given a 1" slope in 8' for drainage. That was originally done by shaving the joists. At this point it is not possible to shim those joists back to the normal dimension. I want to remove that slope and match the floor up to that of the existing bedroom. What is an acceptable way to accomplish that?