Plumbing and Piping - Wyn-t vs. San-t

Hi all, I'm in the process of adding on a 2nd floor (1400 sq ft) to our house. In the addition will be a Master bath and a Guest bath. The master bath will have a tub, sink, shower and toilet. The guest bath will consist of a sink, toilet and shower. All will be connecting to a horizontal 4" drain waste pitch at a 1/4" per foot approx. 6' long. My question is when to use a San-t or a Wyn-t. The 4” will be running between the rooms in other words the one side will be the master (left) the other side will be the guest (right). Where and witch one should I use? Thank you and I hope I gave you enough info.

San Tees can only be used in drainage when you connect a horizontal line to a vertical line, this is the only time, can be use anywhere in the venting system.

Originally posted by animalhog
My question is when to use a San-t or a Wyn-t.

Sanitary Tees must be used to connect a trap arm (from a fixture trap to it's vent). They should never be used in a horizontal-to-horizontal position as they do not have sufficient sweep. In many codes, they are allowed to be used vertical-to-horizontal in 3" and larger sizes (usually under a toilet.)

The reason a wye or TY cannot be used here is that the trap arm must have air flowing in the top half while draining the fixture.
The San tee is designed to provide the proper slope so that the weir of the trap (the part just in back of the trap where the water overflows into the arm) is just below the opening inside the san tee to the vent section. (This is the reason you see the trap-to vent max length liminations in the codes. Too long a trap arm and the weir will fall below the vent opening.)

With a fitting of greater sweep like the TY, the vent opening would be below the trap weir and could be sealed off when the fixture operated, setting up a potential for siphoning the trap.

45 deg wyes with an 1/8 bend, (one-peice combinations are called Long Turn TY's or LTTY's) are used horizontal to horizontal drains, horizontal to vertical drains or vertical to horizontal drains (usually with a clean out opening on the back side.) The wye and TY has greater sweep and can accommodate a slower flow (horizontal drains are designed to flow at only two feet per second with 1/4 / ft slope.)

You can use any bend with any degree of sweep in a vent system (carries air only).

Originally posted by enigma-2


Sanitary Tees In many codes, they are allowed to be used vertical-to-horizontal in 3" and larger sizes (usually under a toilet.)



UPC says horizontal the vertical only drainage, you can never use a san tee vertical to horizontal drainage, in no size pipe.

Why is this, simple, take your average drain cleaner, if he can't see what direction he's cleaning out a line, he can go in the wrong direction.

Vertical to horizontal drainage must enter through a wye, wye/45 sweep or long turn 90

Horizontal to horizontal, must enter though wye, wye/45 or long turn 90

Vertical to vertical drainage must enter though a wye, wye/45

Thanks for your advice. Ley me add 1 thing to the mix. the 4" DW will be below any fixture (at least 9" below the floor) So.. your saying that I should use wye's for all my drains and use san's for my horizontal's?

San Wyes can be used as long as the "BULL" is facing vertically up, any other position requires a T-Y and an 1/8 bend , either street of a 45 with a piece of pipe!! Only other use for a sanitary TY is a cleanout on a vertical run !!!

(This is NY code and may vary elsewhere )

An exception is a San Y can be used as the inlet from a basin or sink, between the trap and the vertical stack!!!!

When a horizontal drain connects to a vertical drain you can use a San-tee, not just cause can use a tee in this manor, this is always so at ant vent tie in, beyond that went you can use a tee of wye / wye 45 combo, after the vent tie in, the preferred way would be to use a wye 45 connection on a horizontal to a vertical drain.

Sorry... But still confused??? So I work on a little sketch to show if I'm on the right track. Please let me know if this is acceptable.


http://www.geocities.com/benatartribute/DWV.html

Looks good to me.

Why did you put a 4" santee on the vertical drop, not that you can't do that, but I would have used a long turn 90 el.

I just thought that's what everybodies trying to tell me but if a 90 is better I'll do that. thanks for all your help I just wanted to get this sorted out before I glue it.
thanks again!

Just make sure it is a long turn 90.

Originally posted by animalhog
I just thought that's what everybodies trying to tell me but if a 90 is better I'll do that. thanks for all your help I just wanted to get this sorted out before I glue it.
thanks again!

Based on your original description, you need to use a 4x4x3x3 double sanitary tee. The left inlet serves the master bath, right the guest. The fixtures themselves will need to be vented.

If you could post a sketch, we may be of further assistance as to what to use where.

A Sketch, look above !!!! Jerry

Originally posted by imjerry
A Sketch, look above !!!! Jerry

Hoo ya. Your right, I completely missed the URL. About the only thing I would comment on is that the wye's are actually LTTY's (a wye bend is actually a 45° bend.)

Now, what did I do with my reading galsses ...

After crawling into my floor to get in the long turn 90 it seems the cast pipe that I'm tying onto with a fernco coupler is to long. the top of the 90 would be about 2" from the bottom of the new 2nd story floor. Figures of course, now I'll lose all of my 1/4" pitch. Do rental places rent out chain breakers? I really don't have enough room to get my sawzall in there since the "bell" of the old cast is right there, but if I had a chain breaker I'll take it all the way down to the cleanout.

Call a rental yard at see if they have snap cutters for rent.

A Sawzall will do it, steel cutting blades, long tedious process but it works Jerry

Did it a few times myself !!!

Get yourself a few blades LOL

I am sorry missed the Sawzall comment, please forgive me