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View Full Version : how many fixtures on a 3" vent stack?



ballvalve
06-28-2011, 08:58 AM
1 washer
2 sinks
1 tub
1 toilet

Every plumber joe has a different idea. Can't reach the building inspector, he's always out to coffee.

Seems to me they could all go on the 3" stack....

Its a tough metal roof and I do not want a hundred holes in it.

What do you real plumbers use as a figure?

Terry
06-28-2011, 09:05 AM
In California, You can plumb a three bath home with one 3" vent.

Most of the time, we would use

2-2" vents, two or three bathroom sets and the laundry thrown in.
1-1-1/2" vent Kitchen

I have only used 3" vents on the West Coast on Condo and Commercial projects.
On homes, I use the smaller vents.

Most of the time, the kitchen is isolated so there isn't much else that can be added.

A 2" line will vent three bathrooms, as long as there are other vents in the system to equal the "area" of one three inch vent.

hj
06-28-2011, 11:22 AM
The number of vents through the roof, has LITTLE to do with the number of fixtures, and a LOT to do with where they are placed relative to each other, and whether the vents can be combined into a single penetration. The number of fixtures IS one determinant as to the SIZE of the penetration, however.

Tom Sawyer
06-28-2011, 05:23 PM
Most codes are looking for one vent that is 1/2 the diameter of the building drain which in most cases would make that a 2" vent given a 4" drain. However, if you want to know how many fixtures can be served by a 3" stack you will need a copy of your state codebook because they are not all the same. I can tell you with certainty though that you will not exceed that on a residence.

hj
06-29-2011, 06:10 AM
quote; Most codes are looking for one vent that is 1/2 the diameter of the building drain which in most cases would make that a 2" vent given a 4" drain

Make that SOME codes. Others require the AREA of the vent to equal the incoming sewer which means FOUR 2" vents for a 4" sewer. Still others require a FULL SIZED pipe from the incoming sewer to the roof. And finally, in some cases after you determine the final size of the vent, it has to be INCREASED in size, (with the minimum size being 4" in many cases), as it passes through the roof to minimize rime frost closure.

Tom Sawyer
06-29-2011, 07:20 AM
IPC and UPC which are the two most used codes are both one vent 1/2 the size, but HJ is correct, you need to know what your local code says. BV is in California which I believe is an IPC state for the most part. Obviously frost closure won't be an issue.

ballvalve
06-29-2011, 10:00 AM
Looking at the mountains up a bit higher and there is still about 60" of snow to melt....

OK, so 5 fixtures, with only one, the kitchen sink, 18 feet away, can tie into the 3" stack and go out the roof with just one pipe - right?

Tom Sawyer
06-29-2011, 10:02 AM
If the kitchen sink is 18' away you are going to have to vent it individually and any other fixtures that are not within trap to vent distance

Terry
06-29-2011, 10:56 AM
UPC Code, California, Washington, Oregon

Trap arm length.
The distance from the p-trap to the vent.

Table 10-1

1.25" 30"
1.5" 42"
2.0" 60"
3.0" 72"
4.0" 120" unless it's a toilet vent, and then 72"

ballvalve
06-29-2011, 11:43 AM
The vent at the sink is very close, but the vent line run to the 3" stack is the 18'

Seems like we should be using automatic vents like a mobile home anyway.

Terry
06-29-2011, 11:54 AM
Most all "auto" vents only work on negative pressure, not on positive pressure.
They also fail and need replacement.

If you have the walls open, I always prefer a vent through the roof, allowing both positive and negative pressure, that doesn't need repairs and they never overflow.

I will use an AAV in a pinch. But they do have their limitations.

hj
06-29-2011, 05:40 PM
quote; OK, so 5 fixtures, with only one, the kitchen sink, 18 feet away, can tie into the 3" stack and go out the roof with just one pipe

Maybe, and maybe NOT. You are NOT telling us HOW the individual vents are getting into the attic so they can be tied together. HOW you do the piping is the important thing, NOT that the "sink is 18' away". That could mean MANY things, some of them legal and others not. It is like you saying, "My car can go 150 mph, is it okay if I drive it", without specifying if you mean on the road or at the track.

ballvalve
06-30-2011, 10:01 AM
Well, the bright building inspector did not know the answer - he referred me to my mech. supplier. that guy says 18 +- fixtures on a 3" stack.

Then he says the 18 feet to the stack is ok from the kitchen sink if its 2".

Amazingly, this same inspector allowed the second story toilet to dump into the 3" vent from the downstairs toilet. [not my house, another copy]Never heard of wet vents I guess.

I had to make the "plumber" cut out the run on mine. For my 5 or 6 future fixtures, he was going to put about 4 holes in my metal roof.

I dont know about you guys, but when I see a house where it looks like it snowed vents on the roof, I see stupidity and future leaks.

Terry
06-30-2011, 10:57 AM
I'm a big fan of vertical.
I like as many of my pipes to go straight up and down as possible.

Popping vents through metal is a bit trickier though. Most of my vents are through comp shingles or cedar shakes.

So.......your inspector never passed his state test? That's kind of sad.

hj
07-01-2011, 06:06 AM
quote; Then he says the 18 feet to the stack is ok from the kitchen sink if its 2".

If it does NOT have an individual vent, then 18' is 12' too far. If it DOES have a vent within 6' of the trap, then you can go as far as you have to to reach the sewer connection. That is why we would have to know HOW you are routing the piping, before we can give an answer. Your plumbing inspector is completely useless and must be the brother of the mayor, because if he does NOT know what is permitted, how can he possibly tell if ANY installation is proper?

ballvalve
07-02-2011, 04:20 PM
I'm a big fan of vertical.
I like as many of my pipes to go straight up and down as possible.

Popping vents through metal is a bit trickier though. Most of my vents are through comp shingles or cedar shakes.

So.......your inspector never passed his state test? That's kind of sad.

The inspector is I believe just a failed builder - for a good reason. And the state test I never heard of. Most state test are made for idiots for pass.

I know better than most because I was chosen with 6 others to Re-write on salary and paid vacation a contractors old test that my 5 year wold would have passed.

BUT I would vent a kitchen sink on 40 ' of 2 " pipe and I'll send HJ 10,000$ the day it stops working....

hj
07-02-2011, 05:47 PM
quote; BUT I would vent a kitchen sink on 40 ' of 2 " pipe and I'll send HJ 10,000$ the day it stops working....

If you are saying you would put a trap under the sink and then run a 2" line 40', WITHOUT a vent, then it will NOT stop working, but it WILL malfunction, which is a different problem, immediately. And if you did do that, then you might be a "general engineering contractor", (whatever that is), but you are NOT a "mechanical engineer" and should NEVER be allowed to do ANY piping installation.

Terry
07-02-2011, 11:28 PM
California uses the UPC Plumbing code.
That is not the same as a contractors test.
The State keeps track of time on the job before a test can be taken.
The minimum is 6,000 before the test can be taken.
If you had half that time working with a "real" plumber, then you would be getting closer to understanding what we have been saying.
Right now, it's like discussing plumbing with the hack that stocks the Home Depot plumbing department.
They think that because the stand in front of plumbing parts, that it qualifies them as a plumber.
I sat in front of the teacher in school, but was considered a "student".
The teacher had teaching credentials. Help me out here. Who is a teacher on the site that can tell us what has to be done before you get your own classroom.

Tom Sawyer
07-03-2011, 06:46 AM
36 years in the field as a licensed master is pretty helpful

Just for clarity though, the 40' run on a 2" line is not a problem if the pipe is properly pitched but there needs to be a vent on that line within the UPC trap to vent distance. Will the drain function without a vent? Sure it will, but there is a high probablility that with that distance and volume, of the trap being siphoned so either fun a vent up or put a Studor on it if local code allows.

ballvalve
07-03-2011, 10:58 AM
quote; BUT I would vent a kitchen sink on 40 ' of 2 " pipe and I'll send HJ 10,000$ the day it stops working....

If you are saying you would put a trap under the sink and then run a 2" line 40', WITHOUT a vent, then it will NOT stop working, but it WILL malfunction, which is a different problem, immediately. And if you did do that, then you might be a "general engineering contractor", (whatever that is), but you are NOT a "mechanical engineer" and should NEVER be allowed to do ANY piping installation.

Dont get your shorts in a wad. Why not wait a bit for the explanation before the insults. Maybe we missed something here. I was talking about the VENT line from the sink, within about 20" of the drain running mostly upwards in order to connect to the single stack out the roof.

The original plumber thought a 3" first floor toilet vent stack could take 2 or three fixtures at most [for venting], and thought it fine to dump a upfloor toilet in that too.

I thought you were saying a 20' 2" pure vent run would malfunction, and I upped it to 40'.

Anyway, I'm not trying to engineer the plumbing, just want it to pass code with a single 3" vent.

ballvalve
07-03-2011, 11:10 AM
quote; OK, so 5 fixtures, with only one, the kitchen sink, 18 feet away, can tie into the 3" stack and go out the roof with just one pipe

Maybe, and maybe NOT. You are NOT telling us HOW the individual vents are getting into the attic so they can be tied together. HOW you do the piping is the important thing, NOT that the "sink is 18' away". That could mean MANY things, some of them legal and others not. It is like you saying, "My car can go 150 mph, is it okay if I drive it", without specifying if you mean on the road or at the track.

Okay so I think some posts got deleted...

But my lousy 2" kitchen sink vent, pure vent is on a mostly up run and then a sharp curve up and right into the 3" stack.

This is an extraordinarily simple house to plumb because I did engineer a truss and wall combination which gives me a 12" deep experior wall to super insulate and run pipes with out a single hole to drill. We laid the half trusses down on the slab, connected them at the ridge and stood the whole house up in one day. Actually enough room in the roof truss members to do the HVAC ducting too.

The whole house was plumbed up in part of a day. NO drills!

But lots of controversy here because I probably didnt describe it all very well.

I came to you small black pipe pros because the Head of building department says call a supply house for info, I have not done any ABS piping for several years, and the "plumber" is a double stacker of toilets that about killed me when i said we could put it all [fixture vents] in one 3" vent stack. Even after I made him run a new pipe for the upstairs toilet.

Tom Sawyer
07-03-2011, 12:39 PM
The important thing to know is that the purpose of vents is to protect the trap seals. Therefore codes list a maximum trap to vent distance.

ballvalve
07-06-2011, 01:00 PM
I built a no-code wildlands cabin and plumbed every fixture with a auto-vent. 10 years later everything flushes like a champ.

Auto vents would kill the pipe and plumbing industry after they allowed pex in.

one advantage of the auto vent in a cabin is the traps dont dry out if you plug the drain or bag the toilet before you leave.

Tom Sawyer
07-06-2011, 01:20 PM
So basically you piped a mobile home LOL

Auto vents are pretty much allowed everywhere and no, they have not killed the industry and they never will because knowlegable plumbers will only use them as a last resort and 99% of the DIY crowd has no clue how they operate nor do they understand what the vent system is supposed to do. Besides which, they are a mechanical device which can and will fail. A properly designed and installed DWV system does not rely on anything other than the laws of physics to operate flawlessly over the course of a lifetime without reliance on moving parts and mechanical devices. That is the beauty of a properly designed and installed DWV system.

Now, if you will explain the logic and physics of the last sentence of your post, we are all dying to hear the explanation there.

We licensed plumbers know things, many things in fact that 99% of homeowners don't know or understand nor do they want to. Some seem to think that this profession ( note the word profession ) can be learned in a couple weeks or by reading books or hanging out on forums. It takes years to master all of the aspects of modern plumbing & heating. Many hours in the classroom, at seminars and in the field. We need to understand and apply math that is well beyond the average high school graduates abilities as well as business and accounting skills to run our businesses efficiently. My cardiologist is a brilliant man. Top in his field. He rebuilt me a couple years ago and because of his knowledge and skill I will be here harrassing folks for many years to come. When his plumbing or HVAC needs attention he calls Us. He call us because as brillaint a surgeon he is he has no idea how to fix his own stuff. I get a little tired of those folks that seem hell bent on belittling a PROFESSION that they have a rudimentary understanding of at best. It's not the materials that will destroy the trade, it is apathetic and ignorant people that have forgotten why we need licensed plumbers. Perhaps a major cholera outbreak would stir their memories but I doubt it.

ballvalve
07-07-2011, 05:42 AM
Granpas vent system gave a place for the water in traps to evaporate to, at least in our dry climate - following that?

AV's close the air connection when the fixture is not in use. closing the drain seals the unit up. A cabin with dry traps and a septic system can give a closed house a rather odd odor after 6 months.

No one is knocking your profession other than there seem to be a plethora of bad and expensive plumbers in this area.

And I wonder where 1/4 of this nation would live without those slimy mobiles with AV's? Damn odd that they actually work!

Your house is filled with joints and new leak points now due to sprinklers, and all those valves in the house are mechanical devices. A well made AV will fail in the open position and for 3 bucks and a few twists, its all fixed. I'll just bet your doctor could understand that valve - pretty much like the ones he sees in a heart.

Maybe you dont know it, but the plumbers union fought pex for millions of dollars. they manage to disallow AV's in many areas still, in concert with the pipemakers. What good is life to a plumber that shaves off 1/2 his time due to engineered materials?

Some of your mob cities still require cast iron - they get a cut from more wages. You may be one of the few true pro's in that field, but I would read up on politics of plumbing - gas in plastic pipe? That took a big fight.

The local 'pro' plumber I called to rod out a main drain said the septic tank was shot. He only had 100' of snake and stopped 5" short of a fix. There was a cleanout in the crawl space 20 feet closer, but it would have meant getting dirty.

After I spent 600 bucks finding the tank and fixing his 5" of cheapness, I got a bill for 175$ Thats a pro, eh?

Funny thing about your doctor, if he slipped and you died, you still owed him 75 grand or more. If you broke his toilet when installing it, who would pay for the new one?

Thats why he calls you - because his last corpse's wife gave him $100,000 to kill him. would you screw around under a sink with that money lingering in your bank account for your slip with the scalpel? A true PROFESSION is where you get to f&*^% up and still get paid - thats doctors, lawyers and politicians, and a some dentists. ARTISANS get to fix their screw ups.

PS. Read "roughing it" good ol Mark Twaine managed to insult every 'profession' on earth in that and a few other novels.

Tom Sawyer
07-07-2011, 05:52 AM
Granpas vent system gave a place for the water in traps to evaporate to, at least in our dry climate - following that?

AV's close the air connection when the fixture is not in use. closing the drain seals the unit up. A cabin with dry traps and a septic system can give a closed house a rather odd odor after 6 months.

No one is knocking your profession other than there seem to be a plethora of bad and expensive plumbers in this area.

Your house is filled with joints and new leak points now due to sprinklers, and all those valves in the house are mechanical devices. A well made AV will fail in the open position and for 3 bucks and a few twists, its all fixed. I'll just bet your doctor could understand that valve - pretty much like the ones he sees in a heart.

Maybe you dont know it, but the plumbers union fought pex for millions of dollars. they manage to disallow AV's in many areas still, in concert with the pipemakers. What good is life to a plumber that shaves off 1/2 his time due to engineered materials?

Some of your mob cities still require cast iron - they get a cut from more wages. You may be one of the few true pro's in that field, but I would read up on politics of plumbing - gas in plastic pipe? That took a big fight.

The local 'pro' plumber I called to rod out a main drain said the septic tank was shot. He only had 100' of snake and stopped 5" short of a fix.

After I spent 600 bucks finding the tank and fixing his 5" of cheapness, I got a bill for 175$ Thats a pro, eh?

Funny thing about your doctor, if he slipped and you died, you still owed him 75 grand or more. If you broke his toilet when installing it, who would pay for the new one?

Unless you are plugging the fixture drains up the water will evaporate out of the drain yes?

You get what you pay for. I suspect you are not willing to pay for a decent plumber so you hire hacks and then get pissed off.

I was addressing mechanical device in the DWV system i believe.

Are you sure they WILL fail in the open position? And when they do they let sewer gas into the house.

Yes they did fight pex and aav's and I wish they had won. It's not always about doing things cheap and fast. Well, maybe it is to some folks LOL

I've heard your drain story before and can't help but wonder why you would hire someone that doesn't have the proper tools and knowledge to do the job. Are you sure you didn't hire an unlicensed handy hack?

ballvalve
07-07-2011, 12:04 PM
Judging by all the tv shows about rotten houses being torn apart, our profession has a parasite rate of about 50% hacks. And they are hard to spot by homeowner joe.

Anyway, my handy hack is a worker to dream of, but is young and the inspector being a bit stupid, has been allowing him to wet vent toilets all around the area. And since his teacher liked to pepper the roof with future leaks, he never thought of one pipe only. As I said its a no drill one wall plumbing job so one stack made perfect sense on THAT house.

The REAL problem is that our schools sold all their woodshops to buy computers. And the metal shops. So they graduate imbeciles that can only be taught on the job, and their mentor might be an idiot. I would say the school system owes me 500,000$ for all the kids I taught a trade to. For awhile they had a training program where they gave me half the wages back, but the kids were best suited to operating a press to make coat hangers. One big strong kid was wiring brushing a huge beam we cut on our sawmill, and actually started crying, and said he couldnt work that hard. left for home.

Another one was a prima dona with some skills, and when asked to clean out the packing shed where all our blankets and plastic is kept, said the work was below him. I offered to help. He said nope. Never had such pleasure firing someone.

Had a nice kid trying to build a cheap garden gate. One swing of the hammer, and had to stop him and ask carefully if he had a father. Well, up to age 3, when he ran off.

I have a 5 year old that can strap off a load on a truck better than one guy I've had for 25 years. And the 5 year old finds PROBLEMS with the load and reports them. Its all about mentoring. If the kid sees a guy with a impact wrench in his hands, all 4 wheels are chocked both sides in about 40 seconds. Unfortunately, sometimes the guy is just walking past the truck to some other job.

BobL43
07-08-2011, 09:30 AM
Judging by all the tv shows about rotten houses being torn apart, our profession has a parasite rate of about 50% hacks. And they are hard to spot by homeowner joe.

Anyway, my handy hack is a worker to dream of, but is young and the inspector being a bit stupid, has been allowing him to wet vent toilets all around the area. And since his teacher liked to pepper the roof with future leaks, he never thought of one pipe only. As I said its a no drill one wall plumbing job so one stack made perfect sense on THAT house.

The REAL problem is that our schools sold all their woodshops to buy computers. And the metal shops. So they graduate imbeciles that can only be taught on the job, and their mentor might be an idiot. I would say the school system owes me 500,000$ for all the kids I taught a trade to. For awhile they had a training program where they gave me half the wages back, but the kids were best suited to operating a press to make coat hangers. One big strong kid was wiring brushing a huge beam we cut on our sawmill, and actually started crying, and said he couldnt work that hard. left for home.

Another one was a prima dona with some skills, and when asked to clean out the packing shed where all our blankets and plastic is kept, said the work was below him. I offered to help. He said nope. Never had such pleasure firing someone.

Had a nice kid trying to build a cheap garden gate. One swing of the hammer, and had to stop him and ask carefully if he had a father. Well, up to age 3, when he ran off.

I have a 5 year old that can strap off a load on a truck better than one guy I've had for 25 years. And the 5 year old finds PROBLEMS with the load and reports them. Its all about mentoring. If the kid sees a guy with a impact wrench in his hands, all 4 wheels are chocked both sides in about 40 seconds. Unfortunately, sometimes the guy is just walking past the truck to some other job.

Just thought I'd lighten up this thread with something about a plumbers problem :-) http://www.myspace.com/video/pancakes/crack-spackle/6263274

Ramon Leigh
07-25-2011, 12:42 PM
As to AAVs - before I moved to Florida 6 years ago, I never heard of an AAV or knew anything about venting systems.
But all the houses in this development use AAVs for all kitchen sinks and bathroom vanities. So when one of the posters
here complains about their unreliability I have to laugh - no one in this development, according to the maintenance folks, has ever had a problem with their AAVs. That kind of thinking, he said, is obsolete - harks back to the days when they first came out and weren't so good. Their lifespan nowadays is such that even mentioning reliability concerns is bizarre.
As to the claim that venting systems only depend upon the laws of nature and therefore last 500 years (as opposed to 60 years for AAVS) isn't a compelling argument. The house itself probably won't last 60 years. And mechanical devices can
outlast you - buy a solar panel and see how long before it dies. Won't be before 30 years and likely will last 100 years.
I'm going to build and am not even considering anything other than AAVS for my vanities and sinks. Based on my personal experience and those of the 750 homes around me, do you really think I am going to pay attenion to the opinion of some Joe who has a vested interest in non-AAV systems ? If so, which planet have you been living on for the past 10 years?

Terry
07-25-2011, 04:34 PM
In new construction, I can plumb a system with vents that will cost less then I would have spent using AAV's.
A little bit of ABS pipe may be a few bucks and the AAV costs about $30 and needs to be installed at trim. Just one more thing to bring to the job. I don't like AAVs, for many reasons.

What planet are you on?

Tom Sawyer
07-25-2011, 05:47 PM
I've been living on the same planet that you have and fortunately I also live in a country where many many diseases have all but been eliminated thanks to modern sanitary plumbing practice. Furthermore I have been fortunate to have been involved in the trade for closing in on 30 years and my father before me was a licensed master for his entire adult life. If unlicensed, unskilled homeowners and handymen want to extoll the virtues of AAV's I suppose that that is to be expected because after all the fast easy way is always the best way yes?

AAV's fail on a regular basis and when the do they allow POISIONOUS sewer gas into the home. A properly designed plumbing system will NEVER allow that to happen and the only reason the damn things are allowed is because the manufacturers and distributors saw a way to make some money so they greased some corrupt palms and got their wish. I have never EVER had to install an AAV in 37 years of plumbing and I damn well am not about to start now. Furthermore anybody that works for me is looking at a pink slip if I catch them using one. And by the way I have NEVER had to tell a customer that the job could not be done either.

ballvalve
07-26-2011, 10:33 AM
In new construction, I can plumb a system with vents that will cost less then I would have spent using AAV's.
A little bit of ABS pipe may be a few bucks and the AAV costs about $30 and needs to be installed at trim. Just one more thing to bring to the job. I don't like AAVs, for many reasons.

What planet are you on?

The Oatley AAV's I see here are about $3.50.... If they make a 30$ one it might actually last 60 years.

Tom Sawyer
07-26-2011, 12:15 PM
Oatley AAV's are not code approved, that's why they are only 3 bucks. All that POS is, is a rubber flap and a weak spring.

Terry
07-26-2011, 01:29 PM
Plumbers have to use code approved parts.