Tub waste question

[tc1]

installing a new alcove tub, drain, overflow, and trap and i'm running into clearance issues.
the waste line needs to make a 90 degree left hand turn shortly after exiting the trap, but the center of the drain is only a few inches away from the joist. (rough sketch attached)

for lack of other options (the other option being laying a san-t on its side) i'm considering a short 180 degree u-turn away from, then back towards the joist.
1. is this ok?
2. instead of gluing sections together can i just turn a trap on its side and use that for the u-turn? the threaded connection would come in very handy.

 

[hj]

I am completely at a loss as to what you are trying to do, but a trap on its side, or ANY 180 degree turn would be a mistake.

 

[Sponsor]

 

[Reach4]

Is your picture a side view or a top view?
Does the circle near the J represent the drain or a pipe?

 

[tc1]

the picture is a top view of the tub, the three wall enlosure, and the waste line thats already in the floor.
the circle represents the drain in the tub.
the real trap will be mounted vertically, but wanting to use a second trap fitting layed on its side to make the u-turn

 

[Terry]

You can swivel the trap to gain more space. Then it might be done with a 45.
You want at the most 135 degrees of change before the vent.
A 1.5" trap arm can go 42" before the vent.

You can also offset the waste and overflow using a streeet 45 for the top overflow, and angle over to the side with it. That picks up quite a bit of space.

Recent codes likes to see glued joints for a tub waste and overflow.

 

[tc1]

thanks terry.

• sounds like a no-go on my 180 idea.
  
• the vent T will be less than 24" from the trap, so should be ok there.
  
• the tub shoe, overflow, and sanitary-t are already glued in the traditional in-line configuration. but the trap is still just dry-fitted at this point.
• i'm reluctant to have a solid glued pipe connection from the tub all the way back to the main waste stack. so i am trying to squeeze in a threaded slip coupling between the trap and vent.
  
• the t for the vent and the slip joint will be easily accessible and not permanently buried under the floor. but the trap is almost unreachable, so that will need to be glued and not threaded.

would a configuration like this be acceptable, or am i still breaking the 135 degree rule?:

 

[Terry]

Why are you makeing such a deep trap?

 

[tc1]

that was just a mock-up using spare parts i had lying around. final version will have correct elevations.

 

[Terry]

that was just a mock-up using spare parts i had lying around. final version will have correct elevations.

With correct parts, yes.
Though I would lose the union.

 

[tc1]

thats been a big help. thanks again.