# Nail Through Vent Pipe



## joecaption (Nov 30, 2011)

That small a hole I would not even worry about it.
If it makes you feel better remove the nail and add a dab of PVC cement over the hole.


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## mikegp (Jul 17, 2011)

Gas doesn't make it into the vent pipe. It's purpose is to allow air to get behind the water so it drains quickly and easily without burbling and tons of drama. Sewer gases are stopped by the trap.


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## DBoone (Apr 3, 2014)

I haven't hit any vent pipes that I'm aware of. I did run new base and shoe in my in-laws bathrooms Saturday and then I thought about "what if". The piece behind each toilet I used 1 1/4" 18 gauge brads and angled them. Just enough to hold and let the caulk do the rest. 

I didn't really think there was a huge risk of explosion but wanted to ask.


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## DBoone (Apr 3, 2014)

Mike, thanks. 

:thumbsup:


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## DBoone (Apr 3, 2014)

On second thought, are you sure Mike? I was always under the impression it had to be vented to the outside because of the gases.


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## ct18 (Sep 20, 2012)

i believe the vent has some gas, would not worry about a nail hole. The trap protects fixture opening from sewer gas.


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## ZZZZZ (Oct 1, 2014)

The gas in a vent pipe is negligible. Otherwise, you would smell it when you were up on your roof.


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## jagans (Oct 21, 2012)

mikegp said:


> Gas doesn't make it into the vent pipe. It's purpose is to allow air to get behind the water so it drains quickly and easily without burbling and tons of drama. Sewer gases are stopped by the trap.


Sorry, but you are partly wrong here. Yes they are to prevent siphoning, but their main purpose is to allow methane to escape from the sewer system. Methane is produced by the anaerobic bacteria that break down human waste.


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## joed (Mar 13, 2005)

If the vent is also a drain line, some are, you might see a leak in the future.


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## DBoone (Apr 3, 2014)

I knew the vent was to allow air behind water to make it drained better. I also was pretty sure it allow any gases to be vented to the outside. What I didn't know was how much gas is usually present inside the vent pipe. So the amount of gas inside the vent pipe is negligible. I didn't know that. 

And just a reminder I haven't hit a vent (that I'm aware of) but was just thinking of a hypothetical situation. Learning for future situations.


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## jagans (Oct 21, 2012)

ZZZZZ said:


> The gas in a vent pipe is negligible. Otherwise, you would smell it when you were up on your roof.


You heven't been on too many roofs have you? :laughing::laughing::laughing:


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## ZZZZZ (Oct 1, 2014)

jagans said:


> You heven't been on too many roofs have you? :laughing::laughing::laughing:


Enough to never have smelled methane.


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## jagans (Oct 21, 2012)

DBoone said:


> If someone is running trim and a nail hits a water pipe you will know it when you start seeing water damage. What about if a finish nail hits a vent pipe. Would you smell the gas? Would the nail plug the hole and 99.9% of the gas exit through the roof?


I guess it would not be kosher to ask how a finishing nail can reach a plumbing vent in the first place, but it sounds like the wrong nails were being used? Oh well, it is what it is, as they say.

There are a couple of things to consider when this happens.

1. Is the vent a wet vent?
2. What kind of pipe is involved? PVC pipe moves quite a bit under thermal change, so that might be a consideration also.
3. If you can get to it, you could just install a SS HWH screw with an EPDM washer and forget about it.

Otherwise Joe is probably right, as usual.


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## Anti-wingnut (Oct 18, 2009)

ZZZZZ said:


> Enough to never have smelled methane.


You wouldn't 





> At room temperature and standard pressure, *methane is a colorless, odorless gas*. The familiar smell of natural gas as used in homes is a safety measure achieved by the addition of an odorant, usually blends containing tert-butylthiol. Methane has a boiling point of −161 °C (−257.8 °F) at a pressure of one atmosphere. As a gas it is flammable over a range of concentrations (4.4–17%) in air at standard pressure.


http://en.wikipedia.org/wiki/Methane


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## Bob Sanders (Nov 10, 2013)

Anti-wingnut said:


> You wouldn't


 I think you're getting a bit technical here. In these instances we use the term "methane" because it's a lot politer than saying SH**


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## DBoone (Apr 3, 2014)

jagans said:


> I guess it would not be kosher to ask how a finishing nail can reach a plumbing vent in the first place, but it sounds like the wrong nails were being used? Oh well, it is what it is, as they say.
> 
> There are a couple of things to consider when this happens.
> 
> ...


Nah I used proper length nails in my install as mentioned earlier. And you're right, a trim nail should never hit a pipe but things happen and I was just bringing a hypothetical question to the forum. Nothing more, nothing less.


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## Anti-wingnut (Oct 18, 2009)

Bob Sanders said:


> I think you're getting a bit technical here. In these instances we use the term "methane" because it's a lot politer than saying SH**


What ever, I know I commonly smell sewer gas when I'm on a roof.


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## jagans (Oct 21, 2012)

Anti-wingnut said:


> You wouldn't
> 
> 
> 
> ...


Well not to be crass, but it ain't methane until it gets broken down, till then it is sheit. :laughing:


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## ddawg16 (Aug 15, 2011)

Well, this thread went to 'sheit' pretty quick

:thumbsup:

I have a 4" vent stack on my roof....If I stick my nose to it....yea, I can smell it....

But unless something is 'percolating' down there, you flush...more air goes in than comes out...does a pretty good job of diluting the 'gasses'.


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## Ghostmaker (Mar 2, 2013)

**** smells at least mine does... Repair it.


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## Jmayspaint (May 4, 2013)

I found a hole in a vent pipe a while back behind a bathroom cabinet. The screw holding the cabinet up had pierced it. 
Apparently it had been there a while, the HO hadn't noticed any odor, but the drywall around it was moldy and punky. 
I first thought it was a drain pipe. 

What is meant by a 'wet vent' ?


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## mikegp (Jul 17, 2011)

Sorry if I was wrong. Is there really much gas backing up into a house with a trap? Does it get around the water during a flush? Just trying to picture this. Thanks.


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## jagans (Oct 21, 2012)

mikegp said:


> Sorry if I was wrong. Is there really much gas backing up into a house with a trap? Does it get around the water during a flush? Just trying to picture this. Thanks.


No, the whole purpose for a "Trap" is to TRAP the methane on the vent side of the system. Toilets have a trap built right into them, and all fixtures have to be trapped (Usually P Trapped) and vented so as to prevent siphoning. In a typical residence there is a main soil stack to which your toilets are connected with a closet bend (Like in Water Closet) and fixtures are drained to the soil stack, and vented above all fixtures.


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## jagans (Oct 21, 2012)

Jmayspaint said:


> I found a hole in a vent pipe a while back behind a bathroom cabinet. The screw holding the cabinet up had pierced it.
> Apparently it had been there a while, the HO hadn't noticed any odor, but the drywall around it was moldy and punky.
> I first thought it was a drain pipe.
> 
> What is meant by a 'wet vent' ?


That looks like a soil stack to me. Looks to be 3 inch diameter PVC?

Wet Vent shown below


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## mikegp (Jul 17, 2011)

jagans said:


> No, the whole purpose for a "Trap" is to TRAP the methane on the vent side of the system. Toilets have a trap built right into them, and all fixtures have to be trapped (Usually P Trapped) and vented so as to prevent siphoning. In a typical residence there is a main soil stack to which your toilets are connected with a closet bend (Like in Water Closet) and fixtures are drained to the soil stack, and vented above all fixtures.


I'm talking about a house trap. Isn't the purpose to trap gas on the sewer side of the trap?


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## jagans (Oct 21, 2012)

mikegp said:


> I'm talking about a house trap. Isn't the purpose to trap gas on the sewer side of the trap?


Not sure what you mean by a house trap, Mike. Unless you mean a running trap or a drum trap. I remember drum traps in old bathrooms and I have seen grease traps in kitchens, but I am not familiar with the term "House Trap" The function of most traps is to provide a water stop to prevent gas from entering the dwelling, though. Maybe a pro plumber can help you more than me. I am not a fast plumber, or a slow plumber, I am sort of a half-fast plumber.


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## mikegp (Jul 17, 2011)

A house trap is in the main line near where it leaves the home.


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## jogr (Jul 24, 2007)

A house trap will definitely stop sewer gas from entering the house dwv system but a lot of houses don't have them. The vent system of a house without a house trap will definitely stink of sewer gas. You will smell at the vent that exits the roof. The fixture traps keep it out of the living area.

I suspect very little odor would be detectable if a nail went into the pipe. More if the nail was then removed.


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## jagans (Oct 21, 2012)

mikegp said:


> A house trap is in the main line near where it leaves the home.


Thanks Mike. They look like a clog looking for a place to happen. :laughing:


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## mikegp (Jul 17, 2011)

Mine has a clean out right before and after.


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## Ghostmaker (Mar 2, 2013)

House traps are installed so you do not have sewer gas up your storm drains (downspouts). They usually are used when combined storm and sanitary are in use. Cleveland Ohio has such a system. The problem with the system is as follows.

Rain that enters the system and your human waste go's to the treatment plant is cleaned and released. This is a major problem with heavy rains. The treatment plant can not handle the extra load. So what Cleveland had to do was dump all that untreated water straight to lake Erie. This resulted in fish kills, algae blooms, And beaches being closed due to human feces in the water. Not to mention Cleveland's water supply is furnished from that same lake.

Now the EPA has mandated that they and other cities that had combined sewers can no longer dump untreated excess water to streams or lakes or any where else. So Cleveland is in the process of building huge sewage retention ponds for the rain runoff that they will have to clean prior to dumping to the lake.

This is why your sewer bill will increase. But it is cheaper then new treatment plants. I suppose if your house happened to be near one of those **** water ponds it would be a bit smelly.

Moral of the story

Keep the rain away from sanitary and build it right the first time.


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## jagans (Oct 21, 2012)

mikegp said:


> Mine has a clean out right before and after.


Yeah I saw that on Google images. We used to call that a running trap. I have seen them a lot on commercial properties in cast Iron with brass clean-outs, never on residential work.


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