Mystery stink in new home -- any ideas?

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by Laurie, Oct 9, 2004.

  1. Laurie

    Laurie New Member

    Messages:
    2
    Hi,

    We're wondering where to turn for an intermittent mystery stink in two bathrooms in our new home. We had the home built for us and have been living here for 8 months, so the plumbing is basically new. Here are some details:

    1) The plumber who installed the plumbing says that the awful smell is NOT sewer gas. It's stronger than sewer gas.

    2) The odor is NOT caused by dry pipes and drains; the plumber flushed out all the pipes in the bathroom, ran water for a long time, and the stink returned after just 2 days.

    3) The odor is like a stinky PortaPotty or latrine, seems like raw sewage to me or possibly something decomposing, but what could take so long to decompose, and why would the stink come and go? We just had 3 weeks of no stink and now it's back.

    4) Plumber says *all* the plumbing vent pipes on the roof reek like sewer gas. He doesn't know why but says maybe it's because our house is at the extreme lower end of the subdivision and that when more homes are built near ours, maybe this will reduce the sewer gas coming out the roof. (I'd love feedback on this theory!)

    5) There is often a smell of sewer gas outside the home. We called public works and they told us our subdivision is built over a new, large sewage pipe. I don't know if it runs under our home though. I noticed the smell of sewer gas outside the home during construction, before the plumbing was installed.
    Public works came and caulked all the manhole cover openings but said it might not stop the smell of sewer gas outside the home.
    I don't know if the outdoor sewer gas smell is related to the stink inside our home. I can smell the outdoor sewer gas smell halfway up the street sometimes. The outdoor sewer gas smell tends to come with the cold and on windy days (things that don't let the gas rise and escape/dissipate).

    6) The indoor stronger stink isn't always present. It comes and goes. We're trying to see if there is a correlation with the weather. Sometimes it comes after heavy rain; a few days ago it came with a lot of wind and a cold morning.

    7) The stink has been present in two bathrooms, one on the ground level, one in the basement. The basement one hasn't been stinking for some months, but the ground floor one does.

    8) The stink seems to be especially bad in the bathroom *sinks* in question. When brushing my teeth, the smell is so strong I nearly gag.

    9) No one else in the neighborhood has a stink in their home.

    10) I've tried pouring different types of cleaners and deodorizers down the sinks, even tried Drain-o, but these don't help.

    Who can we contact for help in this matter? Should we call the Health Dept?

    Any ideas or advice is welcome!

    Laurie
  2. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,313
    Location:
    New England
    Bummer...I wonder if one or more of the traps are being sucked dry because of a problem in the vent system. Try this...on the sink that really smells, slowly run maybe a couple of cups of water. Let it set for 5-minutes (don't run any other water in the house) then see if it still smells. Do you notice the water level in any of your toilets going down, or moving when you are running water anywhere else (when the drain is open)?

    Does anyone else in the subdivision have similar problems? If so, is it the same builder?

    If you can smell it outside, it could just be coming up through openings in the building. If the house is really built tight, it might be that the a/c system is creating a vacuum in the house, pulling in the sewer gas. Do you have a heat recovery system in the house? If you turn off the fan from the a/c (or heat) for awhile, is it worse or better?

    Are you sure it is coming out of the drains and not out of the air ducts? Could be something died in there. Do you have a crawl space under part of the house - you may want to go to the access port and see if it is any stronger there.

    Someone else will probably have some more ideas.
  3. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    27,247
    Location:
    Cave Creek, Arizona
    odor

    Outdoors the odor will often happen on cold windy days. The wind blowing past the roof pipes will draw the odor out and then it will "fall" down the roof to the ground where you will smell it. The big sewer does not go under your house or any one elses. It is out in the street, alley, or easement outside your property lines. Indoors the odor that comes out of the roof pipes can enter the house through bathroom exhaust fan openings, especially if they are close to the pipes. I once had a bathroom light fixture that became scorched due to an oversized bulb, and gave off an odor everytime the light was left on more than 15 minutes, and the customer was positive that it was sewer gase. I also had one who had a dead, decomposing mouse in the dryer vent pipe that had the odor all through the house.
    Last edited: Oct 10, 2004
  4. Laurie

    Laurie New Member

    Messages:
    2
    Thanks for both of your replies. I'll comment on both here.

    > on the sink that really smells, slowly run maybe a couple of cups of water. Let it set for 5-minutes (don't run any other water in the house) then see if it still smells. <

    I'll try this next time the stink is back.

    > Do you notice the water level in any of your toilets going down, or moving when you are running water anywhere else (when the drain is open)? <

    No.

    > Does anyone else in the subdivision have similar problems? If so, is it the same builder? <

    No to both.

    > If the house is really built tight, it might be that the a/c system is creating a vacuum in the house, pulling in the sewer gas. <

    Would this also be the case when the a/c is not being used? I'm asking because it hasn't been on lately, and the smell returned when the a/c wasn't in use.

    > Do you have a heat recovery system in the house? <

    I don't know. What is a heat recovery system?

    > If you turn off the fan from the a/c (or heat) for awhile, is it worse or better? <

    I don't know if this applies since neither the heat nor the a/c have been on lately. But I'll bear this idea in mind next time the stink returns.

    > Are you sure it is coming out of the drains and not out of the air ducts? <

    When I bend over and sniff the drain, the smell is strongest there. Soon after the smell subsides in the bathroom, the stink is still in the drain (if I bend over and sniff the drain). This makes me think the smell emanates from the drain.

    > Could be something died in there. <

    We have field mice in the garage from time to time. I suppose they could find their way under the house.

    > Do you have a crawl space under part of the house <

    No. Otherwise, we would've gone under the house to check.

    HCJ:

    > the odor that comes out of the roof pipes can enter the house through bathroom exhaust fan openings, especially if they are close to the pipes. <

    I'll try to find out if the bathroom exhaust vents/fans are near the pipes.

    > I once had a bathroom light fixture that became scorched due to an oversized bulb, and gave off an odor everytime the light was left on more than 15 minutes, and the customer was positive that it was sewer gase. <

    The smell generally starts overnight and we notice it in the morning. It has happened in two bathrooms, but lately is only in one.

    > I also had one who had a dead, decomposing mouse in the dryer vent pipe that had the odor all through the house. <

    The smell is confined to one or two bathrooms only. I suppose there could be a decomposing mouse under the home, but the bad smell comes and goes. During the hot, dry summer, we hardly had any problem and I thought the problem had disappeared of its own accord. But then when the weather got cooler with wind or rain, the bad smell returned. I don't know if this was just a coincidence or if the weather has a bearing on the situation.

    Thanks for your input!

    Laurie
  5. lakeman203

    lakeman203 New Member

    Messages:
    1
    Location:
    Lake Norman, NC.US
    Odor is Light Fixtures

    Get ready, i am going to solve your mystery. The odor you are getting is coming from either the lamp socket or the trim ring that holds the globes in place or other high density plastic part close to the incandescent lamps. Years ago, these parts were generally made of metal or procelain. Most now are imported and use as much plastic as possible.

    Let me guess, no odor when lights not on for a while, but reoccurs when lights are on and seem to get stronger.

    We had this occur in a condo we purchased and remodeled 8 or 9 years ago. drove us crazy, ruled out sewer gas, dead mouse, etc. Finally made the connection to the new light fixtures in the bathroom and kitchen. These were purchased from national home center chain. We had to replace them prior to selling the unit.

    Fast forward, we built our current house 8 years ago, and in the last three months started smelling an odor near the kitchen door to the garage and in my office which is in an open loft area above the kitchen.

    Wife nearly went crazy, cleaned and recleaned everything two or three times to no avail. Ruled out sewer gas, dead mouse, etc, again.

    This past Friday, traced the familiar odor to the 5 lamp light fixture over the kitchen table. The strange part, there is absolutely no odor when the light has been off for an hour or so, but 5 to 10 minutes after you turn it on, it comes back stronger than ever. Again, this fixture is 7 yrs old and until now not been a problem.

    Hope this helps!!

    hp
  6. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    27,247
    Location:
    Cave Creek, Arizona
    odor

    It repeats what I said a long time ago. The odor recurs when the plastic gets hot so the light has to be on for a while before it happens.
  7. Veronique

    Veronique New Member

    Messages:
    1
    Mystery stink in my new bathroom - ME TOO!

    :confused:A new bathroom was added to our 15-year home several months ago. In this bathroom, we have 2 sinks side-by-side on a 72" vanity: the right sink is fine, the left sink has the problem. The jacuzzi to the left of the vanity is also fine.
    - The problem is the same one Laurie decribed back in October 2004 when it comes to the inside of the house.
    - I have not noticed any smell outside, but then again I have not paid attention to it.
    - We don't have this problem with any other sinks in the house; just this one.
    - The smell occurs whether the window is open or closed, AC is on or off, heat is on or off...
    - The lights have nothing to do with the smell, since within the same room, one sink is fine and the other is not. Even with no lights on, the smell occurs.
    - The only thing I can think of that may be different between the 2 sinks is that on the left sink, when I look at the construction pictures, there's a pipe going straight up to the roof from where the drain is attached (the venting pipe?).
    - I'll close the stopper to the sink to stop the smell and that seems to work. But as soon as I run water in the sink the smell overtakes the room, and for a short while afterwards. Not as much before I run the water.

    It's been driving us crazy. The stench is so bad that, like Laurie, brushing my teeth is very uncomfortable. Even the cat ends up climbing on the vanity to figure out where this smell is coming from! Anyone else had this and was able to resolve it? I'll really appreciate it!
  8. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,313
    Location:
    New England
    Try to notice if the smell is coming from the overflow rather than the drain. Maybe put some tape over the overflow and pull up the stopper. See if the smell goes away. If it does, get a bottle brush and run it down the overflow of that sink and see if cleaning it helps.
  9. Raucina

    Raucina Previous member

    Messages:
    515
    Hard to buy the electric idea when the smell is outside and stronger.

    You can rule out dead animals under the slab unless the mob built the house or poured the slab after a hit. If the city has leaks in its pipes and you are at the bottom of the hill, you might be floating on a hidden river of sewage. Get public works back for a inspection, maybe they can use a methane sniffer. They won't volunteer it but they typically have the pipe maps in their truck and you can have a look if the guy visiting is good natured. Cracks in the slab might allow gasses to rise through... they might camera the pipe if you yell enough. Health department would be a good concurrent step.

    Although you might have leaking pipes under the slab and then it becomes your burden.

    City sewers are installed by private contractors, and when the city inspector takes his 3 hour lunch, they can do some really shoddy work quick and get it covered up.
  10. Gary Slusser

    Gary Slusser That's all folks!

    Then I'd say it is in the water, it could be coming in with the water or... the faucet tip is contaminated with bacteria. Spraying water into a bucket with your nose on the rim smelling the air coming out of the bucket is the best way to determine if the odor is in the water. You can do that at an outside faucet or get in a tub where you don't normally smell the odor.

    To find out if a faucet tip is contaminated, remove the faucet tip aerator without losing parts. Put all of it in a glass of water with a tablespoon of bleach in it, soak it for 15-20 minutes.

    During that time, hold the glass up so the water covers the end of the faucet. Hold it there as long as possible but at least 5 minutes. Don't estimate this time, actually clock it. Ten minutes or more is best.

    When done, rinse the parts and reinstall them. This may take chrome off so limit the length of time you soak the parts.
  11. Herk

    Herk Plumber

    Messages:
    547
    Location:
    S.E. Idaho
    Good call, Gary. I've pulled out plastic faucets that were causing an odor not unlike sulphuric acid. They would only smell on the first use of the day, then the water would clear out the contamination.
  12. Rabid_Rabbit

    Rabid_Rabbit In the Trades

    Messages:
    7
    Location:
    Maryland
    When I was redoing the the tile in my downstairs bathroom I removed the toilet and plug the hole with a rag and covered with a plastic bag. When it got cold then the bathroom would have the sewer stink. Then I started a fire in the living room fireplace the whole house started to stink. Not very helpful for you. All I did was replace the toilet to get rid of the stink. After I did the tile work.
    My point is that it seems that any small leak can let the stink in. Now I'm not a plumber this is just a guess but I think that the differance in air temp and pressure in the house was drawing it up and it squezzed by the plastic bag.
    Last edited: Nov 21, 2007
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