# Bad odour? Lemme check your C.O...



## SSP (Dec 14, 2013)

So i'm in a commercial building downtown , very very old... and this Mens washroom absolutely wreaks in ways i have never smelt as a career plumber with a farming background shovelling chicken n pig **** as a kid ... Just two toilets, one sink, and a urinal. 
The strangest thing i found about this building is the sewer gas pressure is un-real i literally had to keep my lines capped 100% of the time while working and uncap to quickly glue and fasten fittings in place because the gasses would blast out so fast i'd estimate at almost .25-0.5 PSI or so. 
So i figured because the sewer gas pressure was so high that the seals of the clean-outs must be shot, p-traps dried up in FD under lav, screws in vents, toilet seals compromised or even the urinal flange passing. So here are pictures from the Clean-Outs, (BONUS POINTS to WHOEVER CAN IDENTIFY TO INSECTS INSIDE) the previous knucklehead who put the chrome co cover on last decade ago didnt use proper stainless screws or anything that would last, the tips of the screws rusted off causing some of the leaks.

Any ideas on why the pressure is so high? Is this an indication of poor/improper venting or simply more plugged up vents causing back-pressure?


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## Tommy plumber (Feb 19, 2010)

Nasty. Looks like it would gag a maggot....


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## CaberTosser (Mar 7, 2013)

I usually find that significant pressure differences are a result of the HVAC system fans creating those differences. Usually the worst I see the effect is in taller multi story buildings. I had one call where I traced the odor to a poorly set W/C, where sewer gas was just sailing out the gap and smelling up the 20th floor two-level penthouse suite.


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## SERVICEPLUM (Nov 21, 2013)

I also just had a 8 story building getting bad sewer gas in the 4th floor men's room real bad... Smoked test building found a bunch of shut with cracks and c/o caps missing. Also traps dried out.... Fixed all issues and next day smell is the same! After doing some searching found a exhaust van on roof that was so strong was sucking traps dry and causing the Oder. Check for fan on roof! These old buildings have crazy ****!


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## Unclog1776 (Feb 5, 2013)

SERVICEPLUM said:


> I also just had a 8 story building getting bad sewer gas in the 4th floor men's room real bad... Smoked test building found a bunch of shut with cracks and c/o caps missing. Also traps dried out.... Fixed all issues and next day smell is the same! After doing some searching found a exhaust van on roof that was so strong was sucking traps dry and causing the Oder. Check for fan on roof! These old buildings have crazy ****!


Had the exact same thing at our local DMV. Smoke test showed nothing. We were even up in the attic with laser pointers looking for smoke. Only place we got smoke was thru a roof exhaust system that pumped fresh air into the building. Turns out the state made em put it in a few weeks prior and it was literally about a foot from a 4" vent


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## Redwood (Sep 8, 2008)

When you open the door to the building does air go rushing past you blowing into the building?

If it does then the building has negative pressure and needs some ventilation work...


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## Dog (Jan 11, 2012)

CaberTosser said:


> I usually find that significant pressure differences are a result of the HVAC system fans creating those differences. Usually the worst I see the effect is in taller multi story buildings. I had one call where I traced the odor to a poorly set W/C, where sewer gas was just sailing out the gap and smelling up the 20th floor two-level penthouse suite.


 wow that happened to me in a warehouse , the sewer air from a roof vent was going back in from the Ventelation !


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## CaberTosser (Mar 7, 2013)

Not smell related, but lack of make-up air related: I had a warehouse with an attached office where I'd been called to service the bank of 4 furnaces heating the office side. I immediately noticed that I was feeling the effects of CO while in the furnace room, and a quick check of the conventional draft furnace chimneys indicated air being drawn into the building through them! A check over in the warehouse bay revealed a 24" exhaust fan in the masonry wall that was to blame.


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## SSP (Dec 14, 2013)

Redwood said:


> When you open the door to the building does air go rushing past you blowing into the building?
> 
> If it does then the building has negative pressure and needs some ventilation work...


@ Redwood i haven't noticed this here but am happy to know what that means in other buildings i've been in! 

Thanks for he HVAC insight. Old buildings are always a challenge to work on or in because back in the day nobody knew what we know now and we have no effing clue what they were thinking LOL. This building is so old, it truly is an ancient relic , it even has huge glass peaked roofs in the mechanical rooms and main office (alone about 10000 FT) that have huge steel rods coming down with big loops on the ends located in the corners that when turned they will open the roof to vent the building


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## 422 plumber (Jul 31, 2008)

Are those sewer fly larvae? They look like either spit out Copenhagen dip or brown rice.

Sent from my iPhone using PlumbingZone


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## Mike Jessome (Aug 7, 2008)

We actually refer to them as pisss ants when ever you open up a rotting clean out they crawl around and some fly lol


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## titaniumplumbr (Jun 11, 2014)

Shadow makes it look like a crappy yin and yang


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