I have a drop ceiling in a downstairs bathroom that I want to replace with drywall. The problem is....the master bedroom ensuite shower is directly above the basement bathroom shower. So the plumbing from the ensuite shower comes down below the joists making it impossible to drywall to the joist. My question is, is there a length in between the shower drain and the P-trap that is required? And will a P-trap fit in between a 2x6 joist?