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Author:
Hasran (WI)
Hi,
I am planning a bathroom upgrade and want to see if I have an acceptable Waste and Vent plan. The details of the bathroom are:
A. I have a toilet location that is 10.5 ft. from the main 3" Vent Stack / Waste pipe
B. The 3" Main stack only feeds this bathroom
C. Bathroom will have a 1.6 gpm toilet, shower, bath tub, and sink
I would like to make a horizontal run (sloped .25" / ft) run with 3" PVC from the Toilet past the shower and then past the bath tub drains and tie into this run with a 2" trap from each appliance. My questions are as follows:
1) Is it acceptable to have this 3" waste line supporting all (3) appliances?
2) Do I need to have this line vented between the toilet and the shower traps (at .25" slope / ft I believe I am allowed to run 12' unvented)?
3) This 3" waste drain will be suspended below my floor joist in the basement. If I need to vent it, can I come off the top of this pipe between the toilet trap and the shower trap (~2.5 ft from toilet) and then slope up through the floor joists to the nearest wall where I can then install a vertical pipe to get above flood level of all appliances and go to the stack?
4) What size should this vent pipe be.
5) Do I need to install any kind of trap where the toilet will connect to this 3" pipe or does the trap in the porcelain base of the toilet suffice?
I appreciate any thoughts or recommendations anyone might have!!
Thanks,
Hasran
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Author:
packy (MA)
both tub and shower will need to be vented. if one of them is vented 2", it will serve as a vent for the toilet.
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Author:
Hasran (WI)
The bath tub will have approximately a 1' run from where the trap interects the 3" horizontal waste pipe to the main 3" vertical stack and the shower will have approximately a 7' run. So in total I will have:
Toilet ===3'==== Shower ===6'==== Tub ===1.5'====== Main 3" vertical stack
Where would you recommend coming off with the 2" vent pipe or do I need multiple?
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Author:
LemonPlumber (FL)
the tub will have 1.5 feet before horizontal connect?make this the place where it's 2" vent extends upward.
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Author:
Hasran (WI)
LemonPlumber,
My graphic below was illustrating the configuration for the 3" PVC that will run from the toilet to the main vertical 3" stack that goes through my roof (to vent) and down into the basement concrete out to my septic. I will have both the shower and the tub feeding into the horizontal 3" PVC via a trap and a short 1-2' section of pipe.
Basically the tub drain will have a trap running into a 1' section of 2" PVC which will in turn y into the 3" horizontal PVC. From there it will run 1.5' to the main 3" house vent / waste line.
So are you telling me I need to put a vent in the 2" PVC from the tub even though it is only 2.5' from the main house vented drain?
Do I need to do the same for the shower? What purpose does this additional vent serve?
Toilet ===3'==== Shower ===6'==== Tub ===1.5'====== Main 3" vertical stack
I appreciate your help!
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Author:
dlh (TX)
it all depends on how you run the piping and without knowing the floor plan and the existing drain location it is impossible to give you any advice
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PLUMBERS "Protecting The Health Of The Nation"
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Author:
Hasran (WI)
If it helps the link shows a sketch of the layout of the fixtures and the waste lines
[picasaweb.google.com]
I am trying to finish the proposal sketch to visit our building inspector but I want to cover all teh bases because he has very restrictive hours and doesn't seem overly patient or helpfull...
Thanks!
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Author:
packy (MA)
as someone said before, you can't flush a major fixture past a minor fixture..
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Author:
dlh (TX)
the way you have the drains drawn you need to put a vent before the trap of everything except the toilet
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PLUMBERS "Protecting The Health Of The Nation"
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Author:
Hasran (WI)
Packy / DLH,
Combining your posts it sounds like I need to make the following 2 changes:
1) Separate the Toilet waste line from teh Shower/Bath waste line
2) Vent the Shower and Bath tub prior to trap (between the fixture and the trap)
Obviously I am going to have to look at how to tie in this vent in such a short distance (or figure out how to have a longer run to the main wast line) but I think this updated linked sketch at least shows the required adjustments?
Updated Sketch:
[picasaweb.google.com]
For the Bath / Shower waste line can I do everything in 2" PVC or should I do 2" PVC feeders going into a 3" main horizontal line?
Thanks for the guidance!
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Author:
packy (MA)
the lav should not drain to the basement. you can run it inside the wall at 19" above the floor and tie into the 3" stack. if it is within 5 ft. (mass code) it will be stack vented.
just below the floor, you can put a 3 x 3 x 3 x 1 1/2" right side inlet sanitary tee. tie the tub into the side inlet and it will be vented.
where you have marked trap (shower), you need to cut in a 2" Y with the branch rolled up for the vent. it will vent the shower and the toilet.
cabeesh?
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Author:
LemonPlumber (FL)
As said.you are tying the tub and now I see the shower onto a3"horizontal line the water being discharged from the toilet could fill.the 3"horizontal pipe and draw/by vacuum, the water out of both the shower and the tub traps.you need to reconfigure the waste tie in to the main or vent the shwr and tub as tied in on the horizontal branch of the toilet.the major fixture.[@#$%&[img832.imageshack.us]][/URL]
Uploaded with [@#$%&[imageshack.us]]ImageShack.us[/URL]you may not have room above to roll the dry vents but they may join the vent/main stack 42 ' above the lowest vent point.
Edited 1 times.
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Author:
Hasran (WI)
Cabeesh I think!
I will detail a new drawing and post it tomorrow but I think I have a better understanding...
SUMMARY:
Lavatory: drained in wall 19" above floor going to main stack.
Toilet: 3" PVC drain to main stack (via a 3x3x3x1.5) with 2" vented shower drain tied into it
Shower: 2" PVC vented between fixture and trap and then Y into 3" toilet waste line
Tub: 1.5" goes through trap and into the stack via. a 3x3x3x1.5 (no additional vent)
So the stack vents the lavatory and tub and the Shower vent also vents the toilet.
Thanks!
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Author:
packy (MA)
you're a good student..
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Author:
Sewer_dweller (PA)
your toilet sounds like it is too far from the stack, it is in Philadelphia anyway...
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Author:
dlh (TX)
a toilet doesnt need a vent at all since it drains by siphon action anyway
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PLUMBERS "Protecting The Health Of The Nation"
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Author:
Scott the Plumber (PA)
Did I just read this or did somebody spike my drink?
"a toilet doesn't need a vent at all since it drains by siphon action anyway"
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Author:
hj (AZ)
That is true, (in fact MOST drains will work a lot better if they did not have a vent, but that is also the reason why they DO have vents), BUT, the most codes require them anyway.
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Author:
Hasran (WI)
Ok,
The linked sketch below is what I think I will go to the building inspector with next week barring any additional advice.
[picasaweb.google.com]
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Author:
Scott the Plumber (PA)
Even a Philadelphia Single Stack plumbing system relies on increasing the sizes of drainage pipes to allow for air in the pipes as water flows (wet venting) and also maximum fixture to stack distances with regard to hydraulic grade.
Can anybody explain the problems with toilets and fixtures that are not properly vented so if Hasran runs into the issues he knows why?
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Author:
LemonPlumber (FL)
It is code here!No vent.System requirements are still true.A by the book inspector could size the toilet as the diameter of the trap discharge.Many toilets/ newer dual flush\ could fail to meet a major fixture requirements/?\
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Author:
hj (AZ)
I would put the 3" main stack BEHIND the lavatory, so it goes into it directly without an arm. And if there is a wall between the tub and shower, I would put the shower vent inside it.
A sink drain depends on a pressure differential to drain. Without a vent the pressure differential is the height between the water level and the point where the drain connects to another pipe. The greater that differential is the FASTER the water will drain. It is essentially a siphon, and a siphon with one side of the hose hanging over a cliff will drain a lot faster than when it is laying on the ground. The vent "breaks" the siphon so it does NOT drain so efficiently that it sucks ALL the water out of the trap, and as we used to say, "and everything within five feet of the drain, including the baby in the bathtub". It is when there is a stoppage somewhere in the system and the connection to the rest of the plumbing gets flooded that the lack of a drain, OR the installation of an AAV, will cause a drainage problem. At that point a plugged sink drain, or a plugged main drain, can cause the same symptoms, but snaking the lavatory drain will NOT improve its drainage.
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Author:
Scott the Plumber (PA)
We all understand how atmospheric pressure effects a siphon differently than a free flowing drain, thanks to your explanation (sarcasm). However, to have a siphoning effect on an unvented drain after the trap does not apply to fixtures that are not designed to reprime the trap. The analogy of " a siphon with one side of the hose hanging over a cliff will drain a lot faster than when it is laying on the ground." does not apply to proper hydraulic principles. Sounds like a misguided justification of a previous misstatement. "in fact MOST drains will work a lot better if they did not have a vent, but that is also the reason why they DO have vents."
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Author:
Hasran (WI)
In terms of venting requirements if I read th Wisconsin Plumbing Code (found at link below)
[www.legis.state.wi.us]
It seems that on page 16 under "(9) Fixture Vents" it references table 82.31-1 that a 2" diameter horizontal drain can go 8' unvented if sloped at 1/4" per ft and a 3" horizontal drain can go 12' unvented if sloped at 1/4" per ft.
Given this it would seem that I can run the toilet straight to the main stack through 3" PVC and the Shower straight to the main stack through 2" PVC and still be within code...
Comments?
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Author:
hj (AZ)
quote; However, to have a siphoning effect on an unvented drain after the trap does not apply to fixtures that are not designed to reprime the trap.
We are not discussing fixtures that are designed as an "S" trap, therefore repriming them is not even a consideration. The "longer" the outlet drop of an "S" trap is, the "faster" it will drain. Therefore, a "P" trap which has NO outlet drop will drain slower than one which has a long one. The reference to a hose over a cliff was to emphasis how the change in elevation between the inlet and outlet of an "S" trap determines the rate of flow. I can drain a water heater a lot faster if I can run the hose down a steep driveway, than if it just lies on the ground outside the door.
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Author:
hj (AZ)
If you can get away with it, and the inspector has forgotten his basic hydraulics, go for it. But in most areas, you CANNOT connect the tub OR shower to the toilet line before its vent, UNLESS the tub and/or shower has its own vent, nor to the main riser below the toilet's connection.
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Author:
Hasran (WI)
hj,
What about if I did the following:
1) Splice in a 3x3x1.5 in the main stack just below the floor joists and have the tub run directly to this.
2) Put a 3x3x3x2 directly below the 3x3x1.5 in the main stack and run the Toilet and the Shower directly to this coupling with no additional venting.
It this way the Toilet is equal to or below the point that the Tub and Shower connect to the main stack and these lines don't connect until the main stack vent...
Not that I am opposed to adding vents but now my curiosity and inquisitive nature wants to understand everything at play in this system.
Thanks!
Jason
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Author:
hj (AZ)
If the pipe lengths are within the limits, it will work, although it does create a "bulky" installation with those pipes hanging so far beneath the floor joists.
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