Is this considered a s-trap?

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gagecalman

Well-Known Member
Joined
Nov 11, 2016
Messages
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Location
Baltimore, MD
Saw this at a friends house. Trying to learn and understand.

This tub drain goes into a 3" stack that goes thru the roof.
Above the tub sani-tee is a toilet, then the sink before going thru the roof.
All fixtures are within 30" of the stack.
Is this considered a s-trap?
Does the tub or sink need separate vents?
Is it OK for the toilet to drain past the tub or does that create problems?
Thanks for the help.

Tub 2016_66.jpg
 
Not in my opinion. But you shouldn't have a union trap (trap with nut) in a confined space.
 
That also looks like a 2" trap on an 1 1/2" tub waste (a 2" x 1 1/2" bushing on the inlet of the trap).
 
Is the 2" trap a problem or illegal?

Does the tub or sink need separate vents?

Is it OK for the toilet to drain past the tub or does that create problems?
 
The 2" trap is not a problem, it's an improvement actually.

But that is a full on s trap, no doubt about that.
 
If the Y was removed and the trap was lowered to make a longer arm (32") into the stack would the stack wet vent the tub?

Is it OK for the toilet to drain past the tub in the stack or does that create problems?
 
Maryland is under IPC and IPC forbids wet venting below a toilet



2016-11-17_0036.png
 
Would this fix it:

Add a sani-tee to the top of the Y-1/8.
Arm into sani-tee.
Vent the top of the sani-tee.
 
Good morning to all and thanks to everyone for their help especially Frodo.
The AAV's are allowed in Baltimore. They have to meet the requirements of the IPC and it looks like the Studor brand does (Individual-and-branch-type air admittance valves shall conform to ASSE 1051).
Thanks again and have a great day!
 

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