180 degree turn in toilet drain

[snucky]

I am re-plumbing my basement bathroom and am second guessing my plumbing route for the toilet. It currently enters at a 90, runs for 16", enters another 90, runs for 8" and takes another 90 before it runs straight into the main stack. I can easily give it a steeper slope to speed things up but am worried that solids may get stuck in the many bends. Expert opinion would be MUCH appreciated!

Below is a link to a picture of the current setup plus a floorplan for measurements:
http://reimann.files.wordpress.com/2011/09/drains1.jpg
http://reimann.files.wordpress.com/2.../floorplan.jpg

Thanks so much!

 

[LiQuId]

135 degrees is the maximum horizontal change of direction for a reason. 90's are bad news and not allowed in horizontal dwv either ( 2 45's makes a more gradual angle )

 

[johnjh2o]

Also use a Y and 45 instead of the sanitary tee.
If the trap is for a tub you would be much better off if it was a 2" trap with a 2x1-1/2" bushing. That will make it much easier to snake if need be. In most 2" is the minimum size pipe to be used under slabs.

John

 

[snucky]

Thanks guys for your input. If I...

- replace the 90 w/ two 45's and a nipple and
- replace the Tee with a Wye coupled w/ a 45

would you let this configuration pass?

Is the 135 degree rule on a horizontal run a builder's code? All I can find it for is code for clean-outs, not out ruling them per se.

Also, I'll reduce to 1-1/2" AFTER the Pee trap.

 

[LiQuId]

reducing the pipe diamter after the p-trap risks syphonage and reduces the distance to vent you are allowed.

135 degrees is CODE ( plumbing code here in canada, building code covers mostly structure ) there are similar codes in most places.

And the 2 45's dont need a nipple between them ( i know it seems odd ) they offer a more gradual change of direction so there is less turbulance ( which makes the solids and liquids separate and slow ) this is also code.

135 degrees HORIZONTAL change on on and fixture drain is MAX before it is served by a vent pipe. and anything smaller than 4" is MINIMUM 1/4 inch per foot grade.

 

[johnjh2o]

reducing the pipe diamter after the p-trap risks syphonage and reduces the distance to vent you are allowed.

135 degrees is CODE ( plumbing code here in canada, building code covers mostly structure ) there are similar codes in most places.

And the 2 45's dont need a nipple between them ( i know it seems odd ) they offer a more gradual change of direction so there is less turbulance ( which makes the solids and liquids separate and slow ) this is also code.

135 degrees HORIZONTAL change on on and fixture drain is MAX before it is served by a vent pipe. and anything smaller than 4" is MINIMUM 1/4 inch per foot grade.

1-1/2 traps are not allowed under slabs as is 1-1/2 pipe.
I don't see how it would allow siphonage.

John

 

[snucky]

I will have to change my layout then to where I stay under 135 degrees with the toilet drain. Thanks so much for your guidance!

The reason why I went with 1-1/2" for the tub drain was that I was under the impression that the tub drains required the pipe be 1-1/2". I pulled up this product randomly:
Kohler Clearflo Slotted Bath Drain with Overflow | CSN Stores

 

[LiQuId]

larger volume of water creates greater corealis effect when draining, In theory this could lead to momentum syphonage as it enters the smaller diameter pipe it will have more draw. ( though i admit it is unlikely )

Compare the pipe to a syphon, a larger vessel is drained off by a smaller pipe assisted by gravity.

 

[LiQuId]

codes do require the pipe to be 1 1/2 MINIMUM ... you could use a larger pipe such as 2 "

Your tub also appears to be not vented.

 

[snucky]

Hi LiQuid,

i marked the vent location in this picture with a V - it's a 2" vent pipe located in the laundry room:
http://reimann.files.wordpress.com/2011/09/drains1.jpg

I wouldn't mind running the tub drain at 2" entirely. You're saying that fitting the actual tub drain wouldn't actually be a problem?

Thanks so much again, I'm learning so much!

 

[LiQuId]

When i click on the picture i see the V on the left and somebodys feet on the right....

I percieve this picture as this.... To the left is the V ( the vent in room you refer to ) I then see a wye taken off in 2" and then reducing to 1 1/2 that is intended to pick up a tub. Further down the branch I see a 3" pipe that is doing a 135' change of direction to its primary branch... within code ( you dont count the wye fitting change of direction only fitting AFTER.. more about this in a minute ) I then see a 90' bend with a 3 x 2 Wye taken off of it and I assume this is going to pick up a Lav, which makes it a wet vent for the bathroom group. ( you are going to be taking a vent off of the top of the lav t-wye i assume also ? ) i then see the branch terminate to a End cleanout to serve the branch. Do i interperit this correctlly ?

codes differ by regions but here your setup would fail, here are the things that would fail.

1. the T wye ( or Sani-T ) that picks up the toilet is against code. it must be a wye as a t wye is illegal to use in ANY horizontal configuration.. you WILL absolutely get blockages in the pipe over time if you dont change this to a wye and a 45' fitting.

2. the 90' bends must be 2 45's ( some places im told allow for the use of long sweep 90's ) where i am 90s anr not to be used horizontally or on any vertical to horizontal ( horizontal to vertical is allowed )

3. As i assume ( hopefully corectlly ) the lav is vented then you are corerect to use 2" as it is the minimum size of a wet vent allowed to serve a Toilet BUT, in Any wet vented configuration the Toilet must be the lowest fixture, this is so that when it is flushed it cannot syphon off any p traps ( as we do this here we will take the tub drain off of the 2" for the lav using a 2 x 1 1/2 wye, or a 2 x 2 wye in the case of a shower... we are not allowed to take seperate branches off of the 3" line that serves the bathroom group )

to answer your question Yes you could run 2" till after the p trap and then reduce to 1 1/2 as most tubs are set up to accept an 1 1/2 fixture outlet pipe, but it would be easyer to run it all in 1 1/2.

I would take a 45 off of the branch coming into the room and aim straight for the Toilet ( looks like there is enough room to work ), then before the Toilet install a 3 x 2 wye ( pointed in the direction of the feet in the pic ) this would be the Wet vent. I would then Install a 2 x 1 1/2 wye pointed in the direction of the tub ( knowing that i can still use a 45 or a 22 or the throw of the trap to get it exactlly where i need it if need be ), and I would run the 2" wet vent to the lav ( which would be tied to a 1 1/2 vent serving the entire bathroom group ).. I would install a 2" barret cleanout with an access panel to access it in the 2" pipe serving the lav so I could cleanout the wet vent if needed, and i would not install other cleanouts ( such as the one in the floor ) knowing that a clog in the tub could be remedy'd with a plunger and a blocked 3" I could lift the Toilet for access ( legal here in residential installations, but not commercial )

The current venting configuration you have ( even assuming the lav IS vented ) would be considered circuit venting, but would fail as the 3" and 2" and smaller traps must be seperatelly vented.

I will attempt to make a drawing to convey what i've said above, and upload it here.

Keep learning, there is much to plumbing that people dont realize.

 

[snucky]

Hi LiQuid,

thank you so much for your teaching/helping me. I couldn't appreciate this more!

I apologize for not having been entirely clear. The 2" you presume went to the lav actually is a branch-off to the kitchen - which is vented separately - but very far away.

You assumed correctly that the Wye to the left of my feet is a clean-out. I am not entirely sure where it goes after that... I assume it could make another bend to the vanity drain - which is vented - to the left of the toilet drain. If you look at the floor plan, you'll see that I have the fixtures in this order: Vanity, toilet, tub.

I uploaded the picture with my feet in it with better labeling:
http://reimann.files.wordpress.com/2011/09/drains-labeled.jpg
The vanity wet vent is located in the bottom left corner of the picture.


-------


Having pointed out that the 2" vent you were planning on using in your calibration isn't available, how would you vent the configuration? Looks to me like the two vents in the left of the picture are pretty close. Can't I somehow hook up to those? I would have to chip away at some concrete in that room as well.

Thank you so much again. I'm learning so much

 

[LiQuId]

does the pipe past the cleanout ( labled "to vanity " ) continue in 3" and, if so does it pick up other fixtures or another stack ?

how do you upload an image? i got microsoft paint and drew out a configuration but it asks me for a url to post it.

IF the 3" is only there in 3" to be a cleanout access then I would say you should start at the first wye ( the tub ) and instead aim a 45 straight for the W.c. ( water closet ) . Between the w.c stub up and the 45 install a 3x2 wye ( the wye branch would point in the direction of the feet ), this is the lav wet vent and will also pick up the kitchen sink mentioned, it will require 3 45 degree fittings to sweep around the W.c. and terminate at the lav. and then almost immediatelly a 2x 1 1/2 wye ( which would point to the top right of the picture direction ) this 2 x 1 1/2 wye goes to the tub and MAY require 3 45 degree fittings to make the proper termination for the tub but I wager 2 would do it with the p trap sweep. Appologies if this explanation is difficult, It has been a long hot day re pipng in a boiler room.

Alternatelly, although NO LONGER ACCEPTED AS PROPER CODE. but it did work and was accepted for many years. you could take a 3 x2 wye off of the w.c branch and aim for your lav, this would properly vent the W.c. but not the tub although it was done for years assuming the 3" branch could supply suffician air to protect the trap of the tub.

Alternatelly and PROPER.

3x2 wye off of the W.c., aim for the lav. then install a 1 1/2 wye downstream of the tub p-trap and plan to bring a 1 1/2 " pipe into the wall behind the tub where you will tie it into the vent coming off the top of the lav ( IMPORTANT, must tie in above the rim of your sink and no lower, this is flood level rim AND since this vent is considered a flat vent you must take it off above the horizontal centerline of the tub branch, and must use drainage fittings i.e 45's and wyes and such ... no 90's ) This is a code clause that varies widely by region.

If I can figure out how to upload a picture I will do so... it would make things much easier.


Currentlly the biggest problem woth your configuration ( asside from the wrong use of fittings previously mentioned ) is that the tub is Un-vented and when the W.c. flushes it will syphon .