Source of a bad smell?

[frazwood]

Backstory: We bought a foreclosed home last summer. About a month after owning the place, we discovered that my daughter's bedroom smells bad if we open her window (we had run the AC continuously prior to that day). We initially thought the smell was a natural gas leak, so we called the gas company and they checked EVERYTHING but concluded that it was something else.

We continued to try and find the source of the smell but failed until November came around and we didn't open her window again because it was so cold. With the nice weather yesterday and today, we again tried opening her window and the smell returned.

Any thoughts on what this could be? Again, it's only her room and it's only when the window is open.

[Macgyver55]

Mold and/or mildew in the window frame?

[leech~~]

Mac, maybe right but. I would also have all your heating and AC air ducts cleaned, they may even send a cam down a few to see if you have mold or something dead in one of them.

[PurpleFloyd]

Got any pictures of the room and what is out the window? Could it be getting sewer gas from a vent by the window? Could it be something dead outside the house or in an attic? Most of this will just be speculation with what you have provided.

[DTro]

Previous owner a catfisherman?

[nofishfisherman]

First thought was that something could have died in that area but I wouldn't expect the smell to last for that long. If something died last summer you'd think it would be long decomposed by now and not leaving a smell any more.

What kind of a smell is it? Rotten eggs? Sewer? Gas? Etc?

It could also be mold but I haven't been around much mold that produces a real potent smell. It might smell musty but its usually not over powering.

Can you use the old smell test and determine where exactly its coming from? If you can sniff around and see if you can determine if it gets stronger in one area that will give you a place to start.

I'd look to see if there are any vents on the outside of the house near the window, maybe something is venting out near that window. Is there a vent in the eaves above the window? That might be a place to check out.

Is there a sewer line near there? Years back we had a small break in a sewer line near the house. It would create a pretty nasty smell but it also came with a small puddle where water seeped up. Its a complete guess but maybe you are smelling the gases but the water is escaping somewhere else.

[BartmanMN]

If on 2nd level, could a squirrel have gotten in your soffit and died right above the window? I had a bunch of red squirrels get into mine, but luckily I got them all out and plugged the hole.

[CAMAN]

Something dead shouldn't have lasted this long. If there are no vents or sewer/septic in the area, my first thought is mold or rotting building in or around the window. Maybe a nest in the wall.

But it more depends on what it smells like.

[Eric Wettschreck]

Bats living in the soffets.

[Dave S]

Bats living in the soffets.

Had this issue in my last house but they were behind the shutters on the outside of the house. We were cleaning an upstairs bedroom with the windows open and there was a very rank/awful smell coming in.

I climbed an extension ladder to find out there was a colony of bats living behind the shutters on the north side of the house. Both upstairs and downstairs. One had at least 75 bats that flew out when I took it off. I think I bent my ladder from hanging on so tight . The feces and urine odor was just plain nasty. Every night I was going out with a garden hose and spraying behind the shutters to chase them out until they quit coming back. Not to mention there was several extra coats of paint put on that side of the house.

[Tom7227]

I shudder to think what can be behind shutters.

[CANOPY SAM]

frazwood,

It sounds like you really need to supply a little more information to help us help you solve this problem.

The most important questions have been asked here.

1) What does the bad smell smell like?

2) Are there any vents outside the window, either on the wall, or above on the roof, that could possibly be "gassing" into the open window?

3) Have you looked under shudders, inside the forced air furnace or AC vents, or inside the soffit above the window?

I'd pretty much guarantee, if you look closely at all these things, you'll find the source of the problem, particularly if it's just coming from that one window.

Opening that window almost certainly causes more air movement in that room as well. It may be something in or on the carpet in that room? An old urine spot from a cat or dog?

You gotta give us a little more intell. Or at least let us know if you've found anything?

[frazwood]

Mold and/or mildew in the window frame?

The window frame was really dirty on the outside (i.e., the parts exposed to the outdoors), but we cleaned them and that hasn't helped. All of the other windows in the house are like this too.

I have been tempted to rip out drywall and check underneath, but that's a can of worms that I don't want to open until absolutely necessary.

[frazwood]

Mac, maybe right but. I would also have all your heating and AC air ducts cleaned, they may even send a cam down a few to see if you have mold or something dead in one of them.

Thanks. We are hopefully going to hire someone soon to do this (I'm sure that it has never been done and the house is 15 years old, so it's time regardless).

I am thinking that something dead is the cause, but I can't imagine why the smell would only be in this one room if that was true.

[frazwood]

Got any pictures of the room and what is out the window? Could it be getting sewer gas from a vent by the window? Could it be something dead outside the house or in an attic? Most of this will just be speculation with what you have provided.

I realize that I am not giving very much information, but I really don't have much to go on. This doesn't make any sense to me.

There are no plumbing stacks or vents near the window. It's a second-floor-corner bedroom. I can't find any evidence of water intrusion.

I have not yet climbed into the attic. I think that I will be heading up there this weekend. Thanks for the suggestion.

[frazwood]

What kind of a smell is it? Rotten eggs? Sewer? Gas? Etc?

Can you use the old smell test and determine where exactly its coming from? If you can sniff around and see if you can determine if it gets stronger in one area that will give you a place to start.

I'd look to see if there are any vents on the outside of the house near the window, maybe something is venting out near that window. Is there a vent in the eaves above the window? That might be a place to check out.

Is there a sewer line near there? Years back we had a small break in a sewer line near the house. It would create a pretty nasty smell but it also came with a small puddle where water seeped up. Its a complete guess but maybe you are smelling the gases but the water is escaping somewhere else.

It smells like the mercaptans that they add to natural gas. The guy from Xcel Energy basically said, "Yes, that smells like natural gas but I can't find any leaks anywhere." He even checked the neighbor's house.

I am an expert on sewage and it is definitely not that.

The old sniff test hasn't helped. It only happens when the windows are open, so there is a healthy breeze and it's harder to track.

[PurpleFloyd]

Of all the rampant speculation I like Eric's idea the best.Unless the window faces Iowa, then my opinion might change

[frazwood]

Had this issue in my last house but they were behind the shudders on the outside of the house. We were cleaning an upstairs bedroom with the windows open and there was a very rank/awful smell coming in.

I climbed an extension ladder to find out there was a colony of bats living behind the shudders on the north side of the house. Both upstairs and downstairs. One had at least 75 bats that flew out when I took it off. I think I bent my ladder from hanging on so tight . The feces and urine odor was just plain nasty. Every night I was going out with a garden hose and spraying behind the shudders to chase them out until they quit coming back. Not to mention there was several extra coats of paint put on that side of the house.

As gross as these descriptions are... thank you! I will definitely be getting the extension ladder out this weekend and checking it from the outside and from above/inside the attic.

[frazwood]

frazwood,

It sounds like you really need to supply a little more information to help us help you solve this problem.

The most important questions have been asked here.

1) What does the bad smell smell like?

2) Are there any vents outside the window, either on the wall, or above on the roof, that could possibly be "gassing" into the open window?

3) Have you looked under shudders, inside the forced air furnace or AC vents, or inside the soffit above the window?

I'd pretty much guarantee, if you look closely at all these things, you'll find the source of the problem, particularly if it's just coming from that one window.

Opening that window almost certainly causes more air movement in that room as well. It may be something in or on the carpet in that room? An old urine spot from a cat or dog?

You gotta give us a little more intell. Or at least let us know if you've found anything?

Thanks Sam. I'm sorry about the lack of information but I really didn't have any ideas of where to start.

1. It smells like natural gas. We definitely thought that it *was* natural gas until: (a) Xcel energy told us it wasn't natural gas, ( we shut off natural gas to the gas fireplace that is kind of near that room (nothing else is close), and © we haven't blown up yet.

2. There are no vents nearby, in the wall or on the roof.

3. There are no shudders. We haven't cleaned out the ducts yet (why would that only smell in this one room and only when the window is open?) but we are going to do that ASAP. And I am going to look inside the soffit above the window (good suggestion -- thanks!).

4. The carpet in that room is new. The bank replaced all of the carpet in the house after the previous owner moved out but before they put it on the market. But, I'm thinking that the smell would still happen with the window closed.

[frazwood]

Thank you, everyone.

In spite of my obviously insufficient descriptions, you all have given me some great ideas of things to check.

I'll let you know what I find, if anything.

[nofishfisherman]

If it is something dead then its likely several things that have died in the same spot over time. Something that died last summer likely wouldn't still be smelling bad now, not after 6+ months. If you find it you might find a few dead animals.

A few other thoughts...

I'd bet its not in your duct work. If that were the case the smell should be present when your fan is blowing air through the ducts which would have happened all winter long. You'd also expect that smell to be present in other parts of the house and having the window open wouldn't make a difference.

Since it only happens when the window is open I'd start my search on the outside of that window. Do you smell it from outside the house? If so then start checking everything outside. Shutters? Exterior vent? Window wells? Behind siding? Sofit vent? If you don't smell it outside then I'd start taking a closer look at the window itself. Maybe something has died in the wall near the window and somehow having the window open lets the smell escape.

Since the window being open is what allows you to smell the odor then it makes sense to start the search there.

[tunrevir]

Could be possible a cat peed on the sill and the sill never got fully cleaned or it seeped into the underlying insulation. Is there any evidence of water damage? Sometimes when the insulation in the wall gets wet from a window left open it can make for a pretty foul smell as well. Serious on the cat pee too!

Tunrevir~

[nofishfisherman]

That's not a bad guess. Cat pee can be nasty stuff. My mother in law bought a house a few years back in a neighborhood with far too many feral cats and far too many neighbors who let their cats roam all day long. The cats made it a habit to use the area under one of her windows as their private bathroom. It was not a good smell at all.

Ended up having to plant shrubs and put down landscape rock to convince the cats to move on. I also suggested she go talk to the neighbor who was feeding the wild cats or have animal control do it for her. Not sure whatever came of that part of things.

[sptitz]

We smelled natural gas outside of our house, called Centerpoint, guy that came out checked our meter, said it was fine and left, that happened twice. Our neighbors smelled natural gas, called Centerpoint, guy came out checked their meter, said it was fine and left, that happened twice. The last time I smelled it, I called, the guy that came out was very thorough, checked everything gas in our house, furnace, stove, dryer, hot water heater and fireplace. It all checked out fine so I went outside with him, showed him where I smelled it, he smelled it too. He then went to the neighbors that had called earlier, checked everything in their house, found a leak, the gas was going out the vent on top of their house. Long story longer, it took 5 calls to Centerpoint before the leak was found.

[frazwood]

When we got home tonight, we pulled out the extension ladder and looked around the window from the outside. My wife (I'm afraid of heights) could not see or smell anything around the window that seemed out of place.

We did find a small hole in the corner of the house, perhaps large enough for a bat to enter. I can't get into the attic until I get a different ladder (7-ft step ladder is to short, the extension ladder is too long).

Thanks again for the help.