Venting an s-trap

[tigershoops31]

So we're renting our house starting hopefully May 1 and in the inspection today they said we need to vent the s-traps on all 4 sinks. Anybody know what all this entails and if it's a job a novice should attempt to tackle or if you were to hire a plumber if it's an expensive thing to fix?

 

[Rabbuk]

I think you vent them so sewer gas doesn't back up into your pipes.

 

[kberyldial]

Vent pipe are generally behind the walls and vented out of the house - it's a framework of PVC pipe that drain pipes tie into. Vents go up and out and drains go down and out. Not sure how they expect you to vent after the fact but if it's not done it seems to me you have a big mess on your hands.

 

[Cyclonepride]

It depends on if they want to you to vent them all to your stink pipe- if that is the case, that would suck. I put on a vent (see link below) that was pretty easy- just put a T in the line, and install the vent above it. Not sure how that works with your codes.

Funky S-trap

 

[BKLYNCyclone]

It depends on if they want to you to vent them all to your stink pipe- if that is the case, that would suck. I put on a vent (see link below) that was pretty easy- just put a T in the line, and install the vent above it. Not sure how that works with your codes.

Funky S-trap

If this guy is legal in your area, I'd go this route. Otherwise you're venting everything up and through the roof. I don't know enough history of how things were plumbed, but I didn't know people even put these things in without vents. Now I have to go check my mom's house to see if hers are vented or not.

 

[BKLYNCyclone]

I think you vent them so sewer gas doesn't back up into your pipes.

Venting them allows them to drain properly as well while keeping the trap full. Think of an upside down soda bottle filled with water. Glug glug glug glug... But if you cut a whole in the top, it drains perfectly fine. (sweet sound effects)

 

[Cyclonepride]

Trying to remember, but I think I had to buy mine online, as I couldn't find them locally.

 

[Rabbuk]

Venting them allows them to drain properly as well while keeping the trap full. Think of an upside down soda bottle filled with water. Glug glug glug glug... But if you cut a whole in the top, it drains perfectly fine. (sweet sound effects)

Sadly I vented a sink this summer in our bathroom, but still had no idea what the point was.

 

[kingcy]

Why do you have to vent every trap? Most home have the main drain lines vented at some point.

 

[BKLYNCyclone]

Why do you have to vent every trap? Most home have the main drain lines vented at some point.

Cuz the trap is full of water, preventing sewer gas backup in your sink. However, it also creates a seal that prevents the drain from draining properly. A plumber can correct me if I'm wrong... As an architect/plumber's son, I think I know more than I actually do... Actual plumbers can put me in my place.

If there wasn't a trap, you wouldn't need a vent, but your bathroom would stink.

 

[cdnlngld]

Cuz the trap is full of water, preventing sewer gas backup in your sink. However, it also creates a seal that prevents the drain from draining properly. A plumber can correct me if I'm wrong... As an architect/plumber's son, I think I know more than I actually do... Actual plumbers can put me in my place.

Most codes require a vent within so many feet of a drain.....

 

[BKLYNCyclone]

Most codes require a vent within so many feet of a drain.....

Vents also prevent waste lines from being under any pressure. I've seen 6" waste stacks in buildings in ny that literally have holes rusted through them, but they don't leak much because they aren't constantly full of water.

 

[kberyldial]

Cuz the trap is full of water, preventing sewer gas backup in your sink. However, it also creates a seal that prevents the drain from draining properly. A plumber can correct me if I'm wrong... As an architect/plumber's son, I think I know more than I actually do... Actual plumbers can put me in my place.

If there wasn't a trap, you wouldn't need a vent, but your bathroom would stink.

Venting in modern structures clears gases out of the house (pipe out of the roof) and prevents the gulp gulp gulp mentioned earler - or positive flow draining down and out. Better flow out, gases vented out the roof. Traps, that hold water, prevent those gases from venting into the house. My question is in older buildings how they can require this. I get on a rehab that it is code but I'm not sure how they expect a modern venting system to be introduced. Perhaps there is a way - my knowledge ends there. When I finished my basement I ran the venting "system" with relative ease in exposed framing. A vent pipe was plumbed into the basement for this purpose and I essentially finished the job.

 

[CyinCo]

You can auto-vent sink traps with a bit of piping up under a sink. However, most codes only allow 1 or 2 per house. You'll have to check. After that, you need to rework piping to get to existing vents or install new vent piping all the way up and out. Yikes!

This may not be the best source of info, but here is link on Auto-Vents

Sink Vent - Installing An Auto Vent

 

[Cyclonepride]

Venting in modern structures clears gases out of the house (pipe out of the roof) and prevents the gulp gulp gulp mentioned earler - or positive flow draining down and out. Better flow out, gases vented out the roof. Traps, that hold water, prevent those gases from venting into the house. My question is in older buildings how they can require this. I get on a rehab that it is code but I'm not sure how they expect a modern venting system to be introduced. Perhaps there is a way - my knowledge ends there. When I finished my basement I ran the venting "system" with relative ease in exposed framing. A vent pipe was plumbed into the basement for this purpose and I essentially finished the job.

Because they can?

 

[BKLYNCyclone]

Full on vents aren't really a DIY job. You always have to pitch everything back toward the drain, and you can't have any "u"s in the actual vent line as condensation can form in the pipe and eventually fill the "U." For this, you really need to hire a plumber to make sure you don't create new problems.

In a lot of places, this would need to be permitted work, and a licensed plumber can take care of all of that. Otherwise you could end up with a follow-up inspection to rent the house, and then be in violation for doing work without a permit. Work done without permits can triple your cost of permits with the city DOB, if not worse.

 

[tigershoops31]

Thanks for all the info guys, I emailed the inspector to see if converting to a P-trap would be alright...crossing my fingers that I don't have to tear everything out!

 

[fatkid1974]

It depends on if they want to you to vent them all to your stink pipe- if that is the case, that would suck. I put on a vent (see link below) that was pretty easy- just put a T in the line, and install the vent above it. Not sure how that works with your codes.

Funky S-trap

Definitely the way to go if you can get away with it, S traps are pretty much illegal and are allowed to be grandfathered in with this little configuration. S traps aren't vented which can create a vacuum and suck the trap dry allowing sewer gas to rise through your sink, that's why they aren't allowed anymore on new construction.

 

[tigershoops31]

Definitely the way to go if you can get away with it, S traps are pretty much illegal and are allowed to be grandfathered in with this little configuration. S traps aren't vented which can create a vacuum and suck the trap dry allowing sewer gas to rise through your sink, that's why they aren't allowed anymore on new construction.

I sent this to the City Inspector and she said that it wasn't legal to do that way because the parts used for it are "pretty faulty". She did say I had until 2016 to fix them, but I'm still going to be pretty ticked off if I have to knock out 4 walls and put 4 holes in my ceiling...