Author Topic: Sewer Smell  (Read 596 times)

justchecking

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Sewer Smell
« on: November 08, 2017, 05:55:45 PM »
Greetings,

This has been an epic journey for me and I will try to keep it brief.  We have a smell in the third floor of our rental property that is being described as a sewage smell.  It has been happening for over a month off and on.  We have had a plumber out and check all of the lines for clogs etc...  We have had an hvac guy out to check the furnace.  We just had a smoke test done and there were no leaks in the sewer lines.  I have poked around a lot and really cannot figure out where it is coming from.  The tenant is convinced that it is coming from the small furnace room that is in the middle of the house, but there are no pipes anywhere near it.  All the water is on the other side of the house through several walls.  The tenant is convinced that it is an overpowering smell, but the smell is not something that I can detect and the once that I did it wasn't overpowering.  She says that it gets worse at night.
 The last professional we had out said that it might be the neighbors sewage vent that it is a mere 15 feet from our tenants window, but she says that she cannot smell it when she opens the window.  I asked the neighbor if we could put n extended pipe on the sewage vent in case that is the problem, but he does not want to.  The tenant is getting more and more upset about this issue, but I have no idea what to do about it.  They are having company in town for the holidays here and I am getting the feeling that they are going to ask me to pony up and put there people in a hotel.

questions that I have

Do I have to put their people in a hotel?
When can I say that I have done enough and there is not a solution?
What could this mysterious smell be?
Who else should I call to figure this out?
Should I open up a wall and take a peak to see if it is something in there?
Help!!!!

Boll weevil

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Re: Sewer Smell
« Reply #1 on: November 08, 2017, 09:53:26 PM »
I don't know that I have answers for you, but I have some questions which hopefully will lead to a solution.

1. Is the furnace gas or electric? If it's gas, where does it exhaust to?
   1a. Does the furnace room also contain an air conditioner? Air conditioner will likely have a condensate drain

2. Has the tenant been in there for more than a year and just noticing it now, or less than a year? (I use a year because the issue may be seasonal)
   2a. How long has the problem existed (I know you say over a month, but have you owned the building more than a year? Could the previous owner have had the same problem?) Do you know of anything that changed at about that time (i.e. storm, new tenant in another unit)?
   2b. Are any of the other tenants having a similar problem? You may have to actually ask them... I generally don't report an intermittent problem until I figured out a likely cause.

3. When's the last time any plumbing changes were made to the building? What were they?

4. Are all of the drain traps full? If you don't use a sink for a long time they can dry out and let sewer gas in through the drain. (If there's an air conditioning condensate drain, does it have a trap?)

5. Could anything in the building cause a change in local barometric pressure?

6. Is this the top unit in the building, or are there more units above it?

My initial guess would be that there's something wrong in the drain/waste/vent stack for the building or the drains leading to it. If the pressures are all about equal, you're only going to get faint whiffs of the sewer smell. But if for some reason the apartment ends up having a lower atmospheric pressure than the outside, you'd have air coming into the unit through the vent stack, which could bring some sewer gas with it.

Good luck.

Edit: more questions
7. What is the frequency of intermittent? Daily? Weekly?
 7a. On what days of the week does it occur/has it occurred?
 7b. What time of day does it occur/has it occurred?
 7c. Could another tenant be doing something to cause it (i.e. flushing a toilet or draining a bathtub)?
« Last Edit: November 09, 2017, 08:25:19 AM by Boll weevil »

Dee18

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Re: Sewer Smell
« Reply #2 on: November 09, 2017, 05:10:42 PM »
In my former house I thought there was a sewer smell. I could smell it right as I went in and out of the bathroom.  Turned out to be a dead rodent in the attic right above the bathroom.

Kroaler

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Re: Sewer Smell
« Reply #3 on: November 10, 2017, 04:34:08 PM »
Dead rodent.   Nice!   Wouldn't have thought that.

I had a similar issue with  sewer smell.   

Turns out it was a dried up p trap from not using enough.    It's still a problem in the shower, if I don't use it daily I get the smell, I think maybe the p trap is cracked and doesn't hold water but it's in the concrete so I'm leaving it...


justchecking

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Re: Sewer Smell
« Reply #4 on: November 10, 2017, 05:47:19 PM »
Let me answer some questions.

1. Is the furnace gas or electric? If it's gas, where does it exhaust to? Right through the third floor ceiling into the small attic.
   1a. Does the furnace room also contain an air conditioner? Air conditioner will likely have a condensate drain--It does not have AC, but does have a condensate line.  The line is clear and the seal to the sewer pipe is airtight.



2. Has the tenant been in there for more than a year and just noticing it now, or less than a year? (I use a year because the issue may be seasonal)
   2a. How long has the problem existed (I know you say over a month, but have you owned the building more than a year? Could the previous owner have had the same problem?) Do you know of anything that changed at about that time (i.e. storm, new tenant in another unit)?--Had the house a couple of years and no history of the smell.

   2b. Are any of the other tenants having a similar problem? You may have to actually ask them... I generally don't report an intermittent problem until I figured out a likely cause.--Two other units and no problems.

3. When's the last time any plumbing changes were made to the building? What were they?--The third floor, where the problem is, was redone about 7 years ago.

4. Are all of the drain traps full? If you don't use a sink for a long time they can dry out and let sewer gas in through the drain. (If there's an air conditioning condensate drain, does it have a trap?)--traps are good to go.  i cleaned out bathroom and kitchen sink and nothing is smelling from the bathtub.

5. Could anything in the building cause a change in local barometric pressure?--No idea about this but it seems to be worse when it is raining. 

6. Is this the top unit in the building, or are there more units above it? --Unit

My initial guess would be that there's something wrong in the drain/waste/vent stack for the building or the drains leading to it. If the pressures are all about equal, you're only going to get faint whiffs of the sewer smell. But if for some reason the apartment ends up having a lower atmospheric pressure than the outside, you'd have air coming into the unit through the vent stack, which could bring some sewer gas with it.--The only draft that seems to be bringing the smell is under the subfloor, which is exposed in the utility closet. 

Good luck.

Edit: more questions
7. What is the frequency of intermittent? Daily? Weekly?--They say that it is everpresent, but some days are worse than other. 
 7a. On what days of the week does it occur/has it occurred?--There is no pattern here
 7b. What time of day does it occur/has it occurred?--At night
 7c. Could another tenant be doing something to cause it (i.e. flushing a toilet or draining a bathtub)?--I dont think so

Thanks for all of the help this is becoming a larger problem the longer that it lasts. 

Boll weevil

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Re: Sewer Smell
« Reply #5 on: November 13, 2017, 09:36:18 PM »
The furnace exhausts to the attic? That doesn't sound right. But anyway...

So the problem is worse at night, worse when it rains, and may be coming in through the sub-floor.

My next guess would then be that you have a problem somewhere in a wall or floor, and the odor is traveling through the cavities between the joists until it finds a convenient exit, which may be in the utility room. It could be aggravated by moisture.. as the tenant(s) use the plumbing fixtures throughout the day, moisture is added to the problem. Then it dries out overnight and the odor is reduced.

The quick solution would be to somehow block off the flow of air from under the sub-floor (i.e. put a board between the joists or fill the cavity with insulation and seal all the gaps), but that's just treating the symptom, not the underlying problem.

The brute force option would be to actually do some looking, either by peeling away floor, wall, or ceiling, or drilling holes and checking to see if the odor gets worse as you explore in a particular direction. You could also get an inspection camera (see https://www.amazon.com/s/ref=nb_sb_noss_2?url=search-alias%3Daps&field-keywords=boroscope for examples) and feed that through the hole and see what you can see.

More questions:
8. Is the cold air intake for the furnace open to the utility room, or is the cold air ducted in from somewhere else in the unit? Same for combustion air. If the furnace is pulling air from the utility room, the utility room has to be replenished from somewhere, and the floor may be making a small but stinky contribution.
9. You said you've run a smoke test. Have you run a peppermint test?

Not sure what else to tell you.

clutchy

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Re: Sewer Smell
« Reply #6 on: November 30, 2017, 01:52:56 PM »
we had something like that and it was the washing machine.