Elbow before p trap.

[wvphysics]

Can you have any elbows between the p trap and the shower drain? I need to offset a little to go around an obstructing joist and then back to connect to the existing p trap. I am already using an offset drain but it still just barely doesn't clear the edge but I can get an elbow in. The only limits so far I have found are just straight distance vertically and horizontally. If you can have elbows, is there a limit to how many or like a total amount of degrees?

 

[Terry]

135 degrees of change on a trap arm.
That's one 90 and a 45
The p-trap also has a swivel.

 

[Sponsor]

 

[wvphysics]

Thanks. My plumbing terminology might be a bit off so I want to make sure I understand. Is the "trap arm" the section of pipe that goes from the outlet of the p-trap to the rest of the drainage and vent system? If so, I think I may be talking about the "tail piece," the section of pipe between the drain opening in the shower floor and the inlet of the p-trap. Also, these would be vertical to horizontal and back to vertical changes of direction, no horizontal to horizontal changes.