Plumbing Vent through wall

[Mike Lamb]

Is it OK to vent drain/waste through walls?

[kurt]

No. Roofline.

[SNations]

I think it depends on the code.

IRC = yes

UPC = no

Chicago = ???

IRC

P3103.6 Extension through the wall.

Vent terminals extending through the wall shall terminate not less than 10 feet (3048 mm) from the lot line and 10 feet (3048 mm) above the highest adjacent grade within 10 feet (3048 mm) horizontally of the vent terminal. Vent terminals shall not terminate under the overhang of a structure with soffit vents. Side wall vent terminals shall be protected to prevent birds or rodents from entering or blocking the vent opening.

[Mike Lamb]

Does Chicago have an equivalent to the IRC that can be viewed online? Even when I go to the library I find the Chicago building code books less than helpful.

[mjr6550]

Does Chicago have an equivalent to the IRC that can be viewed online? Even when I go to the library I find the Chicago building code books less than helpful.

There should be one on the city web site. Also try this:

https://law.resource.org/pub/us/code/ci ... ldingCode/

[kurt]

Download one of those documents to get an idea of what it's like trying to decipher City of Chicago codes. Fuggedaboudit.....

What you want is HERE....

Click on the "More" button.... Go to division 29, where I found out I was wrong.

"18-29-904.6 Extension through the wall.

Vent terminals extending through the wall shall terminate a minimum of 12 feet (3.66 m) from the lot line and 12 feet (3.66 m) above average ground level. Vent terminals shall not terminate under the overhang of a structure with soffit vents. Side wall vent terminals shall be protected to prevent birds or rodents from entering or blocking the vent opening."

There it is, almost identical to the IRC except for the 12' vs. 10' thing, and I've been told by every union shop in Chicago that you can't do it. Just goes to show......

Just because it's in the book doesn't mean squat. It's what the union guy says whenever they say it. I alternate between hating and loving this city.

It's been a while since I've waded into that mess.....there's a few changes...

[John Kogel]

If it's copper pipe, I advise them to keep it painted to look like plastic. []

Freezing should be no problem because the pipes should drain.

Even so, some old timer thought they might freeze, so he built a box around his outdoor drainpipes and filled that with sawdust. Carpenter ants found that to be to their liking and raised 100 generations of ants there, no doubt. []

[Darren]

Actually, 'freezing' is a concern.

I have seen a 1 1/2" vent pipe that came thru and extended about 2 feet above the roof. The entire interior of the pipe was 'frosted' over. That's why running a vent on the exterior wall is a no no in cold climate areas.

[kurt]

That's why a vent has to be 4" where it goes thru a roof.

[Tom Raymond]

So every 2" vent is wrong? Or is this another Chicago thing?

[Chad Fabry]

The minimum *required* vent size to prevent frost closure is 3 inches. Yes, every 2 inch vent is wrong.

[kurt]

I've seen hard winters where multifamily buildings with 6" vents are almost closed, and 4" is completely closed by frost. 3" is the bare minimum.

Admittedly, frost closure is pretty rare (I've only seen it a few times in my entire career, and it's always early morning/dawn, but if one thinks there needs to be an open vent 24/7/365/infinity, it better be a big vent coming out the roofline.

[Tom Raymond]

I only see 4" vents on balloon frames with wet walls and stuff built after about 1990. Everything in between is a 2" vent. Everything.

[John Kogel]

Plumbing vents don't freeze here. The only 3" vent we ever see is on an old house with a cast iron stack. The old sink vents will be 2" copper or sometimes galvy.

After about 1960, 2" ABS, or 1 1/2". Any smaller and the boot won't fit.

[plummen]

That's why a vent has to be 4" where it goes thru a roof.

Around here anyway its supposed to be increased to 4" 12" below the roofline,although I see a lot of old and handyman special 1 1/2" vents.