Can P trap installed backwards?
Herein, which way does a P trap go?
In a shower P-trap, can the lower curvature be backward? When you cement it together, the straighter side of the trap- which is not as curved- should be what the 90 degree piece is glued onto. Then the curved end should be connected to the shower drain. However, gluing the P-trap shouldn't affect the drainage.
Similarly, how far below drain should P trap be?
According to the International Residential Code, the maximum vertical distance between the sink drain and the entrance to the p-trap is 24 inches.
Slide the short side of the P-trap onto the tailpiece that drops down from the sink drain. Move the P-trap up or down to align the trap arm with the opening in the wall. Use a hacksaw to cut the tailpiece if you can't move the P-trap higher up the tailpiece and the trap arm is below the wall drain fitting.