How to Vent Plumbing

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IMPORTANT NOTE: The bathroom vanity connection you'll see early in the video is AGAINST CODE. The OWNER insisted on this shallow s-trap configuration. The house is in central New Hampshire where there are NO plumbing inspections required by the small town. I told the owner it was against code but he insisted I do it that way because he wanted to make sure he could get a drain-cleaning snake down past the tee. No matter what I said he insisted on the wye and 45.

Carter installed the vent pipes for this plumbing himself in a new home in central New Hampshire in the winter of 2016.

He talks about the importance of installing a full-sized vent on at least one stack all the way from the base of the stack up and through the walls and then through the roof.

There's been a disturbing trend away from using a full-size vent in new homes. Many plumbers feel small 1.5 and 2-inch vent pipes will be enough to vent an entire home.

Small vent pipes can choke off on the inside with ice in bitterly cold climates. When you use a full-sized 3 or 4-inch vent, it takes much more ice to close off the vent pipe.

The plumbing vent pipes create a pathway to let air from outdoors back into the plumbing system when water is rushing down the drain pipes.

[askthebuilder]

The TY fitting you see at the beginning of this video was specified by the homeowner. This NH town had NO plumbing inspections. An inspector would have FAILED the installation as we all know.

[davidmark]

I'm a plumber in Northern Canada. Our code is 3" complete through the roof and it doesn't get much colder than here. 3" doesn't choke off. A vent system allows air to flow both in and out and lets methane gas release out.

[I_Waste_Food]

Thanks for the vid. I have venting that’s suspect in my bathroom. I will be reconfiguring it and connecting to the existing venting but in the correct configuration. I’m glad for the explanation regarding air supply and that the extra 20ft run to the vent header that I’m planning on won’t be an issue. Thanks again for the through explanation.

[butchortner]

Good job on the video. Our modular home only has 1 1/2" vent pipes through the roof. They do freeze over . Now I know more of why. I want to correct the problem eventually. Lots of sheet rock has to come down and 3" or 4" roof vent piping needs to be added. Thanks for the classroom time.

[ralphriffle]

Let's get this straight. Per the Plumbing Code Illustrated Manual. The vent pipe does stop siphonage from happening. You are correct Sir. Now, the vent pipes also makes it possible for sewage to flow thru the sewer pipe in the street. When sewage flows through the main sewer it pushes air through the sewer which escapes out the house vent pipes. As the sewage continues down the sewer it pulls in air behind it. It gets the air from the vent pipes in the house. So, as the sewage passes a house the vent pipe allows air to escape out the house vent pipe. As the Serge of sewage passes by the house the air is pulled into the sewer via the house vent pipe

[davidmarquardt]

Here in Wisconsin, my 1950 house has 4" cast iron. This is from the street, the floor drains, toilet and soil stack. At the roof it has a 5" expander, because the code requirement was a 4" UNRESTRICTED vent opening in case of ice or frost buildup, (we get down to 15 below at times. We got down to 26 below twice, our all time record low). Bathroom sink and tub/shower were 1 1/2 galivinsed pipe, wet vented. The kitchen sink at the other end of the house has its own roof vent, with a 2" galvanised drain into a 4", 4 foot cast iron riser with clean out. About 30 years ago, I replaced all the galvanised drains with PVC. Although they looked okay on the outside with no leaks they were clogging because of rust build up.

[michelemarch]

I really appreciate the detail with which you made this video. And nothing distracting. Thank You So Much!

[elmono]

Plumber telling you he would run 2" vent is not necessarily wrong. He actually knows what he is talking about. 2" plumbing vent handles 24 F.U ( fixture units ). So in your situation, it is perfectly OK, and up to Code, to combine all vents from all plumbing fixtures shown into one common 2" vent.

[StoneysWorkshop]

I never thought about it this way.
I should have.
I work with water vac (ejector) systems for chambers to create negative pressures for sterilization.
Thanks for opening my mind to this for a more complete understanding of
plumbing systems

[mkohare]

amazing video. I'm trying to build a half bathroom and a full bathroom on the complete opposite side of the house as my stink pipe/drain stack, one on the first floor and the other in the attic, and this in invaluable information. luckily for me the difference is not 50 to 60 feet long like this one! thank you.

[sadsciuidae]

13:30 Must allow drainage for condensation & RAIN... yay!!! ... though i would typically not see a 50 ft run just a second roof penetration, Ive not used 1-1/2 for anything in the last ten years ... .

[moorelandhouse]

Wow! Thanks for the useful information. I was able to use it when I did the plumbing on my brother's bathroom. I put up a DIY video and felt confident that I had it right thanks to your video.

[bobburchett]

This is an awesome video that explains the venting in a very easy to understand way. Thank you so much for this video. You are a very good instructor and I am so happy I found this video.

[realdeal]

Hey i'm in plumbing school right now at the 4:56 mark you have used a wye fitting but at school the teacher said to use a sanitary tee for smoother water flow and better air you tell me why you used that fitting or if a tee would also be also really enjoyed your video

[monoralph]

Nice neat installation. Except, at 9:10 the studs were cut apart. Why, as the adjacent studs were drilled for your piping?

[golfsky]

Our 65 year old home has one vent that the toilets tie into but none of the 4 sinks or tub are vented at all!! We don't seem to have any issues but I'll keep this in mind if there are strange smells.

[MartyHuie]

Just so I asked the right question, as you stated there must be a slope all the way from the top of the vents there must be a slow from the top of the vent stack all the way to the drain. Am I able to group all the vent stacks in my home into one so I have one penetration through the roof is my real question, and likely I would like to penetrate the side wall not the roof so I have no penetrations through the roof, well I just got the answer below about going through the sidewall I will address it with the inspector where it would penetrate no one would ever see yes I know it would look odd

Thank you very much for this hoping to do all my own plumbing in the new home I am building in climate zone six in North Carolina the area is actually climate zone five but that's for the whole county I'm at the top of a mountain and I know it is totally different up there so I'm raising the climate zone location. Understanding all this is great.

[isaaccampos]

Thank u for this video I appreciate it as an apprentice trying to learn

[rett]

@ 4:28 you use a 45 wye. I saw another video that said you should use a wye tee for these connections because the 45 wye can cause flow that will block the vent air and actually siphon water out of the p trap. Have you heard of this. The guy I watched said this wouldn't pass inspection, but he is in Canada. Thoughts?

[fpchauvette]

Thanks for establishing equilibrium, and it cannot be said that a vent pipe isn't used for venting air from the system that can otherwise back up without being released. Just try to get a bathroom system inspected and passed without a vent pipe. Frozen pipes happen due to improper insulation, not the vent pipe. The reference, alone suggests the pipe is for venting.. a reference used for releasing air. Otherwise, the vent pipe would be called "air intake". If you're searching for a way to create the effect of the world smelling like one huge sulfur field, (and there are already enough of those around) just wait until those organic gasses build up and cause an explosion. The earth already accommodates such activity in natural vents called Volcanoes and hot springs. We don't need any more created in plumbing systems. 😎