One possibility is that the contractor used Chinese drywall. There are known issues w/ this product. Do some on line research.
I would like to know how you make out. Good luck

Interesting, I had never heard of Chinese dry wall. However, no dry wall was used in the remodel... the original walls (some knotty pine) were painted over but not changed in any way.

Is there any way you can try to be more descriptive in the smell? You outlined what it ISN'T but I'm trying to understand from your passage what it IS. Is it a musty, natural smell? A moldy smell? A chemical smell? A death smell? Cigarette smell?

Hmm. Could it be mice? I'm constantly fighting them, here, even during the summer. Don't know HOW they get in, & they're very sneaky about making their presence known! I finally got them all "out", & I'm vigilant about traps. But the odor lingers & drives me insane! It's distinctive, different from anything else, disgusting (excrement!), & in un-reachable places! Inside walls, under cabinetry, etc. Even if there aren't any mice there now, there very well could have been while it was empty for so long - and the smell can definately hang around long after they're gone. (I'm the only one in the family that notices it... But I swear I do!).

sorry, krycek1984, for not being able to say what the smell smells like, because it isn't like anything I've smelled before, and everyone who comes by is equally unable to place it.

not musty or moldy smell, not cigarette. I've had the misfortune to smell an animal dying in an apt wall I was renting in college days, and it's not that... yuck. I guess it's closest to a rotten egg smell but it's not that exactly, and it's close to a sewer smell, but I'd put this smell in that family, if that makes sense? I;d call it a smell more than a stink. The smell doesn't make you lose your appetite or anything, but it did used to give me a headache and make me sneeze, did not have the same effect on my husband, tho. I'm certain everyone who comes to the house notices it although some people are polite and don't say anything. But the first thing a child will say when entering, is "what smells?!" If I bring it up to an adult they say, Oh yeah, what is that?!
.
Anyway, the point I'd like to stress is that this smell not going away, not decreasing in intensity, despite airing out the house each weekend for 4 moonths. So it must be eminating from something?

Thank you, antiquesilver, for asking about new waste vent stacks, I don't know the answer to that one and I will talk to my husband about that. And, to reply to ks_toolgirl, I have never seen mouse droppings in the house, but there certainly could be critters under the house. that;s a good thing to check. The neighborhood has deer and racoons, etc. So if something is living under the house and pooping, would that explain the smell in the house? But there is no smell outside the house (unless the windows are open, so you smell the inside).

I really appreciate all of your input!

Might animal urine be in the subflooring?

Do you have gas in the house or propane? A small leak in a joint or pipe can make a horrid stink and give you a headache.

Might also be a pipe that isn't slanted the right direction for drainage. Water collects it stinks.

Could also be bats in the attic or walls. It only takes a 1/4 inch opening for them to get in. The build up of bat guano can stink up a place too.
Stand outside at twilight and see if you see any coming in or out...........tho given it's fall they might have migrated already for the year depends on where you live.

Inspectapedia has some further suggestions. Too bad electronic noses are still limited to medical, lab and industrial applications.

The house is just 700 sq feet, one level. The 2 (very small) bedrooms have new carpet, the rest of the house has new slate tile, so I don't think the smell is from something that soiled the sub floor.

Carol_from_ny, the house has natural gas. There is a gas water heater off the kitchen and a gas stove. The furnace is under the house in the crawl space. But the smell isn't the distinctive gas smell. The ac/heat is turned off when we're not there, could the furnace still emit a smell, something other than natural gas, when it's not running?

And, my husband said there was dry wall installed, since they removed the ceiling to put in can lights. Lastly, he also said there is a water barrier sheet under the house, this was added as part of the remodel. He is going to talk to the contractor to see if anything else was changed and what might cause the smell, since the previous owner/occupant said the smell wasn't there prior to the remodel. My thanks again to all posters, if there are any other ideas/suggestions, please add them here.

Mama_mia, my (embarrassing, lol) suggestion was that "previous" mice could be causing the smell, not current inhabitants. It can last a LONG time after they're gone.
Not "under the house" so much as IN the house. I've been told they find ways to get between wall studs & other places hard for us to get to for cleaning up! (dangitall!). Mice are tiny, and seek shelter indoors. Even if house is un-lived in. They manage to thrive, even without humans going to Sams Club or Cosco to stock their food supply. I hope it's something else for ya! Something easily dealt with and done.
:-).

Mama, it sounds like you're on the right track at least. If it is something that didn't smell before the remodel, but smells now, I think it's smart to follow the logic in that.

So now that you know there was new drywall put up...you can explore the possibility that it may be the drywall. And something could be going wrong with the vapor barrier, it's hard to say.

I don't ahve experience with homes that have a crawlspace, only basements, so it's much easier to inspect stuff down there and if there's any grossness, smelly stuff, etc.

I hope you do find out what is causing the stink, how frustrating for a vacation house that is supposed to RELAX you, not AGGRAVATE you!!!!!!!

Jonnyp might have hit the nail on the head! Don't know where you live, or why Chinese drywall might still be available, but here is an excerpt from a google post:
"The drywall is alleged to emit sulfur-based gases that smell of rotten eggs and corrode piping and wiring, causing electronics and appliances to fail". It also makes you sneeze.
You may want to look into this....yikes!

Could be off-gassing from the new carpets or the slate could be cheap Chinese slate. I remember someone on the kitchen forum had received a shipment of slate last year that stunk. She said it was really, really bad and after letting it sit out with the boxes opened up for a week, it still stunk something awful, so she decided to return it. She fought with the company for a bit about being able to return it, and when she finally got the ok to return the slate several weeks later, it still stunk. The Chinese slate is more brittle and slakes off more than the domestic stuff. It wouldn't hurt to check your floors.

mm

this is a mystery

Read the above here are possible culprits:

Cheap Chinese dry wall -
New carpet or padding
-slate or the mastic used?
Improper vent stack

Old possibilities
Animal feces/urine in sub flooring

unlikely
animal decay - eventually that would stop smelling

Continue to act like a detective - what other new items came into the house during remodel?

Also, you are relying on builder & PO word that the smell did not exist - I would see if there is someone who visited the house that may be able to back that up or not. Perhaps a RE Broker that was showing the home prior to remodel

in the interim -

Charcoal, baking soda & white vinegar left around throughout the home may help in absorbing some of the offending odors

GOOD LUCK!

Try preserving the odour and trying it out on more discriminating noses. See link.

My step-son has such a derelict sense of smell that he doesn't even notice skunk. (Perhaps why his mother insisted that he bathe every day whether he thought he needed to or not.)

Here is a link that might be useful: Smell Patch Test

You all are great. Thanks for your suggestions, thought provoking questions, and pointers to websites. My husband is in the area today anyway, so based on when I've learned from all of you, he is going to go under the house to look at the furnace (maybe there is a leak?) and also to check for signs of animals setting up their own vacation getaway under our house. I forgot to respond to one question above, there aren't any bats in the area, so probably not guano.

He will also try to find some copper wire inside the house, in a socket for example, to see if there is a change in the copper finish... per the websites, this is a good test for the presence of Chinese drywall. From googling, it seems there aren't many cases of Chinese drywall around here, but there are some. Crossing my fingers it's not that, because that would be a mess (and expensive) to correct.

I think the smell has to come from something that is still generating the smell... otherwise, I imagine that the smell would dissapate over time, and it has not.

That inspectapedia website is really interesting. I read the questionaire and checklist and keep on coming up with "other." very frustrating!

It smells the same in all rooms so I don't think the flooring is the issue, sine some rooms have slate and the bedrooms carpet. It really seems to be in the air, rather than in something - I mean I don't get a varied level of smell as I go closer to a particular room, or wall, or floor or anything. It's just everywhere. Like I said, even opening a closet and I smell it in there, too. Not to sound like a horror movie, but now I'm really thinking it must be coming from under the house.

hi everyone, just wanted to provide an update, things are looking up.

My husband went under the house and saw that the drain bucket for the condensation coming from the furnace had tipped a bit, I guess settled into the ground, so the pump indicator was on the higher part and was not sensing that the bucket was full and the pump needed to go on... therefore the bucket was overflowing and there was a puddle of water collecting on the vapor barrier sheet.

There are some holes in the sheet, since the sheet goes around the central support beams, and cannot touch the furnace, so some water had found its way to the ground (that is a good thing, otherwise there would have probably been more water) Anyway, the collecting water was definitely part of the smell.
Also, he had the gas company come out to check the gas line and there was a teeny tiny leak (1 on a scale of 1-100), so he got some loose screw tightened, which showed the leak was then fixed. Btw, he said that when he called the gas company to ask about a possible gas leak, they were there within 15 minutes!

He then called the home inspector, who suggested installing a dehumidifier under the house; that will be done this weekend. I'm hopeful that these three changes will fix the problem and the smell will go away! Thanks again for all your help.

mama mia said: It's not sewer gas, or a natual gas smell,

Why it's good to get some "outside" noses in on the stink!

I'm betting you got it.

Could be dead mice. A way to get rid of smells is rent an ozone-generating air purifier and let it run full-bore for a day. Ozone will get rid of any smell caused by long-chain organic-based molecules as the ozone breaks up the molecules. If you do this, find another place to stay while the machine runs as otherwise you will get a sore throat and headaches. Once the machine is off, the ozone quickly reacts and converts back into plain old oxygen so you can get back into the house as soon as you turn it off.

Sufficient ozone causes human red blood cells, which are supposed to be shaped like a hockey puck, to become spherical, in which configuration they work less efficiently. I vaguely recall seeing this problem explained in a non-add for a non-existent Braun electrostatic air cleaning machine, which was invented but not marketed. Braun spent money on ads in Europe to educate the public about the effects of ozone. Do not expect to find this on the Web, because the non-ad was published in the 1970s.

"Sufficient ozone causes human red blood cells, which are supposed to be shaped like a hockey puck, to become spherical, in which configuration they work less efficiently."

Ozone, O3, spontaneously breaks down into O2 and a free oxygen atom.

The free atom is very reactive and can even casue burns at low temperatures and high enough concentrations.

Think of it as the ultimate 'free radical' that can get loose on your body if inhaled.

Ozone is used to deodorize things since it can easily combine with molecules it comes in contact with and oxidize them.
This often changes how they are perceived when we smell them since the the shape of the molecule is altered.

I had to laugh, not at your dilemma, but at your comment about children - you can always rely on a child to say it like it is. LOL.

Embarassing though. The previous owner of our home let their dog urine all over everything. We yanked all the carpet out, and luckily there were hardwood floors underneath. In getting them refinished, the stains came out, but still on our second floor in humid weather we get a bit of that smell. So then you have to explain to people that it's imbedded in the floors. I don't smell it so much these days, so maybe with the passing years it's getting better, or we're just getting used to it. Charcoal helps absorb odors.

My first thought was possibly mold between the walls. Hopefully you've resolved the issue.

brickeye,

Thanks for making it clear that it is the free oxygen radical and not the ozone itself that is the source of the trouble.

I cannot recall another instance of a company spending money to invent a product, then taking out ads to explain that the invention would not be marketed because it would harm the customers.

Do you have a crawlspace? Do you have a vapor barrier? A dehumidifier would do wonders for removing moisture and mold odors also. My home had some real 'fine' smells to it before I had the space encapsulated and put in the dehumidifier. Makes a huge difference!

Teresa

Is the house properly vented. My sister bought a lake house and it never smelled very clean, not awful, but certainly not good and worse at times. Upon remodeling they found the bath vent was pulling it out the room and then back in...can't explain it but in short they said it was venting back into the house.

This might not explain the smell when you first arrive though?

I appoligize but i dont know how to start my own thread to ask a question but im looking for advice. My home has a strange sour smell to it. we moved in about 3 months ago. Had carpets professionally cleaned. I am a very clean person. no dishes in the sink, laundry always done exct. Once im in the home for a lil while i dont smell it any more. but if i leave and when i walk into my home im hit with this sour smell. I dont know how elas to exsplain the smell but sour. We do have natural gas and propain heaters in my home wich i have never had before now. could that be it? I have co2 detectors in every main room in the home and havent had a problem. Nothing i do seems to get the smell out and im at a loss. can someone please help?

I know this is an old thread, but I'm hoping the OP is still around and can provide an update. Inquiring minds want to know...did you solve the mystery stink?

I have the odor of something soured at the front entrance. It's kept clean, hedge trimmed away from house...I cannot find or get rid of it. Help!

I'm with karateken123, I'd love to know if mama_mia really did resolve the odor problem she wrote about in 2010. What she is describing sounds exactly like what I have been fighting in a small house I bought in June 2015 (still haven't moved in.) My odor also defies all normal description and typical odor causes. I've tried lots of things and I've had a dozen experts from various fields in and no one knows what it is.

I had some success with an ozone treatment, but the odor was back in a few weeks. I thought that humidity and/or heat hitting the house made it worse, but since it is cooling off now, and the odor has been steadily bad anyway, I am starting to suspect that the amount of wind might be a variable that causes the strength of the odor to fluctuate and not heat or humidity.

My situation is a little different from mama_mia because my house is a slab-on-grade, so no crawl space, and the odor is strongest on the south facing side of the house, where my front door/vestibule and kitchen are situated, but it does either carry to or exist in the other rooms of the house-just not as strong.

Please, don't reply if you have only the typical recommendations--this problem defies all normal solutions and I've been working on it and researching for months. Unless you have something that is NOT typical to suggest, then you can be sure I've thought of it/tried it.

We've finally discovered where they buried Jimmy Hoffa?

This isn't exactly related but years ago I spent several weeks in a motel in Tennessee and kept smelling dog crap. It was Spring and the door and windows were always open. There wasn't any dog (daog) and there wasn't any crap (crayup). It was a bush outside the door. I stuck my nose right into that bush to make sure. It was the bush.