PLUMBING Roof VENTS for a simple cabin.......Is one vent enough.....?

[Sourdough]

If all of the plumbing is Back-to-Back in the same interior wall, can you get by with only one roof vent for one toilet, one shower, two sinks......?

[Rick]

I don't know why not. I've never plumbed more than one drain-waste-vent and I've never had any problems as long as all drains are tied into it. What are your concerns?

WE can probably help with this one, too.

[welderguy]

Ive seen a lot of A-frame houses and a lot of mobile homes only have one plumbing vent, Im guessing a lot will depend on building codes in your area.

[Pal334]

One is completely adequate,especially since you are "back to backing" it what I have done though is make it slightly oversize. No real reason, just figure the bigger the better

[Sourdough]

What are your concerns?

DEATH, caused by (Colorless & Odorless) Methane Gas. or systems not draining because of air-lock.

[Rick]

Okay. I thought you had some specific concern since you're on a septic. You have to have air backflow to feed the aerobic bacteria as I understand it. I've never been on septic that's why I asked if you had a concern.

[Sourdough]

As I understand it the MAIN reason for roof vents, is so the second floor dump from a bath-tub or toilet does not back-up into a first floor sink/shower/etc.

The problem is it will be snowing in about 80 days, so I need to think ahead about drilling 3" holes in the roof.

[crashdive123]

If all of the plumbing is Back-to-Back in the same interior wall, can you get by with only one roof vent for one toilet, one shower, two sinks......?

Yes..........

[Sourdough]

Thank you, everyone. And so it shall be one 3" roof vent. (I like them apples)

[Rick]

Here's some reading for you.

http://en.wikipedia.org/wiki/Drain-waste-vent_system

[Pal334]

Thank you, everyone. And so it shall be one 3" roof vent. (I like them apples)

Since we handled that one well, shall we take on world peace or something next?

[Sourdough]

Since we handled that one well, shall we take on world peace or something next?

That or: UNDERSTANDING WOMEN 101

[Rick]

Hot dang! Now we're talkin'. The difficult we solve right now. The impossible takes a while longer.

[wareagle69]

is this all on one floor? for the fixtures mentioned 2 in vent is more than adequate,until you go thru the roof (vtr) then cut a peice of 3in about 18 inches long and stub it thru the roof at least 6" about the roof depending how high up you are venting out. the reason for the 3" is just for frost hoar, 3" should not frost closed preventing venting. imagine sticking a straw in a soda then putting your finger over it, fluid stays in the realese your finger fluid go out-venting. Same as poring out that 2ltr bottle of soda glug glu glu, now pucnh a hole in the bottom , and vola smooth drainage-venting.
now if one sink is downsatirs then the vent needs to run upstairs and tie into the vented fixtues above the flood level rim of you highest fixture-normally the sink and questions SD give me a call and i'll walk ya thru it

[kyratshooter]

You need to place the stack within 5-6 feet of the drains.

If you have all of them back to back you should be able to accomplish that.

My kitchen sink is 10' fron the stack and it girgles some. I knew better when I did it.

[Pal334]

That or: UNDERSTANDING WOMEN 101

Oh yea!!!! I am your man for that!!! It has only taken me a bit over 35 or 40 years (mmm memory may be part of my problem also) to realize there ain't no such thing . And I have the bruises to prove it

[Sourdough]

is this all on one floor? for the fixtures mentioned 2 in vent is more than adequate,until you go thru the roof (vtr) then cut a peice of 3in about 18 inches long and stub it thru the roof at least 6" about the roof depending how high up you are venting out. the reason for the 3" is just for frost hoar, 3" should not frost closed preventing venting. imagine sticking a straw in a soda then putting your finger over it, fluid stays in the realese your finger fluid go out-venting. Same as poring out that 2ltr bottle of soda glug glu glu, now pucnh a hole in the bottom , and vola smooth drainage-venting.
now if one sink is downsatirs then the vent needs to run upstairs and tie into the vented fixtues above the flood level rim of you highest fixture-normally the sink and questions SD give me a call and i'll walk ya thru it

Wareagle, Everything is on one floor, still a 11' by 23' one room cabin. Two Questions: first, I get a lot of snow, often 6' to 10' of snow on the roof, does the 3" vent need to extend higher above the roof........?

And I am wondering why I can't run it through the ceiling into the well ventilated 4/12 pitch roof truss system, and with a "T" and double vent it out the gable ends, as this area is protected by roof overhang, and eliminates the deep snow problem, as well as the damage to the vent when shoveling snow off the roof.

[crashdive123]

I know you said it is well ventilated, just remember some of what vents is flammable.

[randyt]

I would vent it out the gable end and glue a 90 degree ell on the end with the 90 pointing down and put a screen on the 90 to keep birds out of it. this method is now approved by international plumbing code. I do it this way now and then but prefer to go through the roof out of habit.

if you feel you need more vent you can also revent your fixtures. which is basically a vent that ties into the vent in the attic but you still only have one penetration. also I try to tie a fixture like a sink into a vent, I feel this is a good practice because it keeps the base of the vent stack washed.

[Alaskan Survivalist]

It is far simpler than you guys make it out to be. The vent is simply to give the fluids someplace to go. Fluids going into a pipe must displace whatever is in the pipe, even air. It is the opposite of a gas can that needs to be vented to get gas out of it. You only need one vent at the end of the system so the air in the pipe can be pushed out of the way for the water. Your septic system should have another vent in the pipe ten feet from the house, two in the tank and one in your pit.