tub drain rough-in question

[Taylor]

Greetings all, I have a quick question about rough-in of tub drain.

Current set-up (by plumber) has tub and lavatory 1-1/2" drains connecting in a wye. What has me nervous is that the tub drain does a horizontal 90 before going into the wye. Presumably the trap will go in at the head of the 90 when the tub is installed. Since the head of the 90 is pointing parallel to the tub (if you see what I mean), I guess there will be more turning involved in or around the trap.

Since I had to cut out that 90 anyway to replace a joist (carpenter screwed up), I am wondering if it would be advisable to beef that 90 up to a 2" drain line, then a reducer to 1-1/2" after the 90 and before the wye? The tub drain goes straight into the wye, lavatory drain comes in at an angle.

Thanks for any help.....

[hj]

Personnally, I always run tub drains with 2" pipe and a 2" trap with the reducer in the trap's inlet. But you cannot increase 1 1/2" to 2" before that elbow, if that is what you are asking.

[Taylor]

I'd like to ask the plumber to put in a 2" trap, after I've replaced the 1-1/2" elbow with 2" elbow and reducer. That elbow strikes me as a prime candidate for blocking. It sounds like you're saying I can increase 1-1/2" tub drain to 2" (i.e. increase outflow capacity), but not vice versa? Shucks....

Ideally I'd like to go with 2" all the way to the wye, but after several retrofits (it's a long story) there's no more room for further splicing....

[plumber1]

I would never worry about a tub drain with a 90. Have done service work for a long time . Tub drains don,t get plugged very often , Many times the clog is within the w&o..You can also use 2 45s to make a longer sweep 90. or roll two 45s or 60s