My crawlspace smell problem is not ordinary or easily resolved but I am hoping someone might have some thoughts on what might be the cause.
First let me give you some back ground information on the building and steps taken to remediate the smell so far.
The original building was built in the 30’s, was a warehouse next to a railroad spur so the floor is set at dock height about 4 feet off the ground. The crawl space ranges from 30 – 40″ of clear space from dirt to bottom of floor joist. The framing, by the way, is old growth cedar nominal size lumber (a 2×12 is really 2″ by 12″) with super tight grain. The smell was present when reconstruction began. I disassembled the entire skin of the structure and reassembled to current building codes. Several exterior wall sections had areas of wrought and mold due to bad stucco or roof leaks but all of that framing and materials were removed. Basically, I have built a new building on top of an existing foundation and floor.
From the beginning I had planned to seal the crawlspace using the latest techniques and procedures outlined in many of the trade journals but not adopted by local building codes yet.
Crawlspace conditions:
the dirt has been dry on the surface and even dry at 12″ deep in some locations where I installed a emergency drainage system. During most of the construction The side walls were open and the space had complete ventilation during the hot dry summer here in California . At that time there was a crawlspace smell. There are no signs of mold or fungus on the exposed cripple walls and sub flooring system. The dirt floor has been cleared of all cellulose materials and large rocks, exterior cripple wall framing and band joists have been insulated with R19 and exterior concrete footing walls insulated with rigid insulation boards R11 (with termite inspection gap of 2″). The dirt areas have been covered with not one but 2 layers of 6mil poly sheets sealed to the concrete cripples 12″ up with polyurethane caulk. My crawl space sealing job was based in-part upon the Fine Homebuilding feature on crawl space containment.
Still I have smell.
I then brought in two crawlspace experts who do this sort of thing for a living, both said they didn’t see any signs of mold, said I have done better work than their own crews at drying in the space, and they had no idea as what or where the smell was from.
So, as a precaution I installed a commercial grade dehumidifier set the automatic controls to 48% relative and off near 43%, it turns on maybe once a day for 30 minutes. In addition I rented a fogging machine and fogged the entire space and all surfaces of the crawlspace with Concrobium Mold Control. Still I have smell.
I have bought a commercial grade Ozone generator to combat the smell and anything producing the smell. I have performed many 8 -10 hour treatments to the crawlspace when no person is in the building. The results are a combination of heavy ozone smell and the crawlspace smell, still not gone. I run the ozone machine once a week now, still no help.
My last effort has been to at least remove the smell from the building living space by creating a negative pressure in the crawlspace, which of course slightly defeats the efficiency of sealing the crawlspace. I now have a continuous duty inline fan pushing crawlspace air outside which draws outside air from the living areas. The result is very little smell inside (my wife, with her bionic nose, can still smell it) but now we have the strong odor outside. I have just diverted the smell problem but have not stopped or removed it.
To help monitor the air conditions I installed remote humidistats in the crawlspace, one near the NE corner and the other near the SW corner of the space, another is based in our living room and finally one outside. I am in the Bay Area in California so outside humidity levels range from 20% on very dry summer days to 85% on foggy mornings and higher when we have rain, which has not happened very much( we are on 3rd year of drought). The crawlspace NW reader ranges from 48% – 52% consistently and the SW ranges 41%-46%(closest to the dehumidifier). The living space has been 45% lately.
I am pulling my hair out on this problem.
Do you know of any case like mine? What could be producing this unrelenting smell?
Could it be a gas of some sort?
If you have any thoughts about my crawlspace smell I would really appreciate them. It has taken the last two years to complete our home but my wife refuses to move in (understandably) until the smell has been removed. It seems to smell like trichloroanisole known as TCA (cork taint in wine).
Any thoughts would be greatly appreciated.
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Replies
Just a shot in the dark, but maybe the smell is coming from the framing wood itself.
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wow, that was a lot of reading to get to the smell.
so you have a smell "like cork taint in wine" which you believe to be emanating from your crawlspace.
maybe someone can help with the cliff's note version.
k
maybe you are on top of an old oil well?
Now you can afford not to live in the house you just built.
Really, I hope someone here can help you with your problem. My post just marks it in my list so I can review it from time to time to see what is suggested to resolve your problem.
Good luck!
I assume the crawl space is vented. Next question is do you have adequate number of vent spaces for volume of space? As someone mentioned smell could be in the wood having soaked up the odors after all these years. I guess next thing would be to install fans to get some airflow through the space. Do you have a vapor barrier between the crawl space and living space?
You can eliminate the wood as a source of the smell, by painting/sealing it. There is a special kind of paint made for sealing wood after it got smelly from mold, smoke etc. Sorry, I don't know the name of it. Perhaps Kilz would work to seal it?
Had any skunks living in there?
If afterwards of sealing, and the smell remains then it must be from the earth. I don't know if it really does anything but I've heard of people spreading powdered lime in the crawlspace.
Have you tried a lot of mothballs down there?
Quantum materiae materietur marmota monax si marmota monax materiam possit materiari?
Any old creasote timbers?
What was in the warehouse? Could it be contamination from that? If nothing else works, you could always lose about 6" of the dirt, lay a poly or foam seal, and crete the deck.
Mike Hennessy
Pittsburgh, PA
I would treat it like a smoke damaged structure. Crawl under and use an airless sprayer on EVERYTHING you can see.
I have had great sucess with BIN Zinser, the oil base. It's a hassle to clean out the sprayer when done, but it has sealed every smoke smell I have ever used it on.
Once it's done, let the space air out for a few days and that should help, if not, just let a bunch of feral cats under there for a week, and the tainted wine smell will be replaced with something else!
There is a little house, not far from here, that was built after WWI with lumber from ammunition crates. No mold or anything on the wood, but talk about a house with smell. To this day if will just about knock ya down when you walk into it.
You didn't mention anything about DWV pipes running thru this crawl. Perhaps because there aren't any. But if there are and they are cast....try running your hand along the very top of these pipes. Have seen quite a few of these crack down a seam after they get some considerable years on them.
The local outfit around here that specializes in fire restoration work and the like uses alot of aluminum paint to seal in odors. Works great. Same basic principle as using Zinnser's BIN which is a white-pigmented shellac product. Shellac makes an excellent vapor barrier and so does a thin film of aluminum. A couple coats of either should do the deed on your timbers/lumber....if that lumber isn't contaminated with something that will cause serious adhesion problems.
Do you know the history of what the warehouse was used for? That includes what it was used for at night in addition to what its reported purpose was. If not, I think you may need to check into the possibility of industrial contamination. This would involve the services of an environmental contamination specialist. This could open a can of worms that you don't want when you find you have a superfund site under your house. On the other hand, if the problem is some nasty carcinogen, you probably don't want to make it home sweet home even if you learn to live with the smell.
Don't count on the poly to seal any odors that may be coming out of the ground. It won't do it. It takes a while for things to leak through, but they will.
I was going to ask if there was any way you can have your soil tested, but just thought of a few experiments that you could do yourself for free.
1. Just gather some soil samples from around the crawl space. You might want to dig down a little in a place or two just to get some representative samples. Keep the samples separate & label them as to location. Put them all in something like a cheap styrofoam cooler & let them set a few days. Open up the cooler & sniff (carefully). If you get the odor, you can separate the samples & see if you can identify a specific location.
2. The second experiment I was thinking of probably won't work because the floor framing has probably been exposed to the odor long enough to absorb it. However, I'll post it anyway. Take a wad of sterile gauze or probably just a handful of sterile cotton balls & some sort of heavy unscented plastic, e.g., ziplock freezer bags. Fill the bag with the gauze or cotton & staple the opening of the bag tightly to a framing member so that the gauze or cotton is exposed to the wood. Let that set a few days & then check for scent. If you get some odor in this case, unfortunately, it doesn't tell you what the source is, but it should give some indication of whether or not the framing itself has absorbed some of the odor.
Hope you get something that will help you. Best of luck addressing the problem
One thing comes to mind. Just an idea.
Instead of pulling a negative pressure in the crawl space, pull one under the plastic.
You would have to get the plastic off the ground somehow. Maybe round gravel so it doesn't puncture the plastic when you move around on top of the plastic. You could also extend a perforated pipe under the plastic to pick up gas from further under the plastic.
This is how it is done for radon abatement.
So you've got the smell completely gone from the structure.
Then extend the line with the fan on it further away from the building. Figure out what the prevailing wind direction is and put the end of the pipe down wind.
You might have to increase the power of the fan.
This would get the smell out of your house and away from it.
I agree with several of the posters here. It would seem that you have practically eliminated the crawlspace as the culprit leaving the floor framing as the next logical suspect. I would research the original use of the loading dock. The SF area never had a big passenger or general goods train system built before the car came into fad, mostly specialized for local industry i.e. lumber and dairy on the coastline. If you are in the East Bay where there were a lot of industrial and chemical plants, the framing may have soaked up years of industrial use that is out-gassing heavier than air particulates that sink to the crawlspace area. Sealing all might help arrest that, and lab testing should offer some clues.
>>>Basically, I have built a new building on top of an existing foundation and floor.
Just a thought.....
- Take a number of small core samples of joists, subfloor, and other framing members, label them carefully as to where in the structure they came from, and put them in individual zip bags.
- Now go away from the building and open each bag. Take a whiff. Are they all stinky or some of them? Think about where in the frame the sample was taken and how strong the smell is.
I too think you've all but eliminated the crawl space as the culprit. Time to think about what that warehouse beside the rail line might have been used for.
Always remember those first immortal words that Adam said to Eve, “You’d better stand back, I don’t know how big this thing’s going to get.”
I have lived in the bay area all my life. If I knew the locale, I might be able to give you some ideas. Email me if you'd rather not post.
Well, if nothing else, I learned about TCA.
http://en.wikipedia.org/wiki/Cork_taint
Did an old Portuguese guy live there?
It sounds like old house smell and I would go with sealing the lumber as others suggested.
But it seems that someone who has been under your house and smelled the oder would have already suggested something similar.
I the original interior plaster still intact? I think that can contribute greatly to the classic musty old house smell, if exposed to moisture in the past.
I live in Alameda in an old house (1885) and would be willing to have a sniff around and give my 2 cents, if its close by.
Mike
Small wheel turn by the fire and rod, big wheel turn by the grace of god.
If you ever DO figure out what the smell is, please report back. This is a good puzzler.
Here's hoping you don't pull out all that hair....
Scott.
Always remember those first immortal words that Adam said to Eve, “You’d better stand back, I don’t know how big this thing’s going to get.”
Supplemental to all of the good ideas that the pros have posted, here are a few thoughts that could be potential culprits:
1) A plugged drain from a central heat & air unit, and/or a moldy drain pan. (Assuming you might have such an arrangement in the crawlspace.)
2) It's possible that the house might sit on top of a void or cavern that could collect gases, the same way that mines do. (I live in the Ozarks, where the bedrock is swiss-cheesed with caves & voids, some of which flood with the water table & other collect gases.) While radon itself is odorless, I'm wondering if radon testing might render some clues, since radon tends to collect in underground cavities. I'd think that testing could also be done for methane & other gases--you never know but what a buried antique sewer line that you never knew existed might have collapsed under or near your foundation.
It's probably not cheap to do, but you might be able to consult a geological engineering firm to see it they can get an idea of what the ground underneath your structure sits on if all other options fail. Since you live in an area famous for seismic activity, I think it makes sense to eventually explore what's under you.
Hello All,
Thanks for responding to my crawlspace issue. I will test the soil and framing members this weekend. After gathering some historical information on the building and site I have a feeling the culprit might be microbial activity in the soil. But why a TCA smell? And if it is coming from the soil how can I stop it?
To help answer some of your questions here is the building history and related data: Site was once used as a nursery 1930's (No structures), circa 1933 the warehouse was constructed for use as a grainery used 25 years, next inhabitent was electrical components storage 15 years, and the last was as an Upholstery shop until 2005.
No signs of a super fund site. The crawlspace dirt was cleared of all cellulose (which was not very much) before laying the poly down.
Checking with the city engineer only one sewer lateral has ever been established for the lot and I replaced the line from the curb to the structure. Inside, the entire plumbing system is new, no leaks.
I have contacted some local gas testers to get their input. I'll let you know any results.
Thanks
Mark Wagter
Electrical component storage? Did this include transformers?
I don't believe so. There is no sign under the building that anything was dumped or stored in the crawlspace. We found some old milk bottles dated in the 40's, several mummified cats, well preserved. Otherwise nothing else of any significance.
The electrical components storage was more a ship in ship out warehouse.
Smell persisting after all this time? So dry it mummified cats? No benefit from the ozone? Let's look at those items, and what they suggest.
Most any 'organic' cause .... mold, bacteria, dead animals .... would have been eliminated by your cleaning, venting, and sterilizing with the ozone. So ... either the odor is continually being re-introduced, or it's not anything organic, a chemical in nature.
Odor can be re-introduced by your drain and vent lines. I'd pressure test them, and see if they leak. Then I'd make sure the vents are not also blocked.
Then there's the possibility of a gas leak. Or, in a similar fashion, there being either the tank, or the residue from, an oil heating storage tank. Both contain smelly sulphur compounds.
Last winter's "big job" included a crawl space that had installed two ducts, a fan, and a humidistat. The ducts went up two floors, and exited through a "chimney." Air in, air out. Any odors were vented up high, and not at ground level.
I'm betting on the framing. I worked in a Berkeley warehouse loft conversion years ago. It was located on the railroad tracks and the wood had a foul odor of creosote and diesel as well as a thick layer of filth.
The owner pressure washed the interior and the black sludge ran out the door back to the tracks from whence it came. It smelled a lot better after it dried.
I do a lot of remodeling and most old lumber has an unpleasant odor.
I bet you're in for a nasty oil base sealer job.
Kurt
The "electrical components" might have included high voltage transformers and the like that contained various types of oil, some of which might cause such an odor.It would be useful to know if the odor is coming from the soil or from the structure. If the suction system were placed under the plastic (use runs of perforated pipe) then the odor should either decrease (if from the soil) or increase (if from the structure).One possibility is that the soil on which the building rests once held an outhouse or a feedlot or some such.
The mark of the immature man is that he wants to die nobly for a cause, while the mark of a mature man is that he wants to live humbly for one. --Wilhelm Stekel
old transformers carried HIGH amounts of PCB's. Although you are opening a can of worms by getting it tested, you might save yourself from sleeping with worms sooner than you planned on (sorry, bad joke)
Seriously, if you can't determine it as an organic odor, the chemical odor seems to be a realistic scenario
Saturday, Dec. 13, I watched an episode of "Flip This House." This sounds so much like what the buyer found, worse problems then you may have, I hope. He ended up tearing off the sheet rock, flooring, kitchen cabinets, discovered leaking plumbing in the crawl space, vermin, such as dead rats, etc. He was way over budget by the time the job was complete. I wish I had paid more attention as they recommended a paint using a sprayer that will kill smells on the walls. I wish you well.
Reading through teh first 27 posts, if it isn't something impregnated in the wood, it wood seem that it would have to be some kind of outgassing from the soil. I think i would start digging. Eventually you may be pumping concrete to make a floor in your crawlspace. Whatever it is, you can't ignore it if you and yours (actually, if anyone) are gonna be living there. Good luck, and let us know when you discover the answer to the mystery.
Further thinking about those 'mummified cats:'
What killed them? Just how decomposed were they?
For example, if there were boxes of rat poison also found, they may have been poisoned by prey they caught. In that case, there are likely dead rats around as well.
Or, had there been a cat colony living there? Cats do mark their territory; this can produce a skunk-like smell. Their ####, as it decomposes, can also be quite smelly. On the 'plus side,' these cat markings will glow when exposed to a "black' light. Unfortunately, your ozone treatments should have eliminated any such "biological" causes.
Back to the dead cats .... when bodies decompose, they largely liquify, and soak into the soil under the body ... leaving the hide, and the bones. This fluid will really stink as it decomposes, and your ozone treatment would not have penetrated the soil. For that, about all you can do is pour plenty of bleach on the spots, and wait.
So was there any resolution to this problem? Always nice to have some closure on these type of threads.
John
Unfortunately not. Still trouble shooting. I'll report back on progress as I make it.
Thanks,
Mark
I had a buddy that had crawlspace mold UNDER his tightly sealed poly and he couldn't ever seem to get rid of it. Are you wanting to get rid of the smell completely or just out of your house? Maybe spray that expanding foam insulation on the underside of the joists, crawlspace walls, AND ground?
Crawlspace encapsulation materials outgassing?
Hello - wondered if you ever solved your issue with crawlspace smell. I live in GA and had my crawl encapsulated in the Fall. Have a dehu down there and everything seemed to be in order. But when AC kicked in this Spring we started to get a strong smell in the house. It is like a cat urine type smell. Researching it now but some have said it could be outgassing of the plastic or adhesives used. Will evenrtually go away. I don't know if toxic. Need to test it but where and how? Does anyone know if this could be the reason for the smell?
my experience, maybe it helps
I added on to my parent's house back in '95. About a 20x20 addition, with a laundry room, bathroom, and a dining area, extending off an existing/remodeled kitchen. Did a pressure/leak test on the plumbing, got everything else tidied up. All good. That winter, started getting a sewer smell in the area. Checked all the joints, all well. Kept getting it, especially in the crawlspace. Disconnected the sewer line in the old house, plugged all drains (pulled fixtures), and retested, no problems. Not fun, but had to know.
Fast forward three years later. We're digging an outdoor faucet line from the house to the garden out back. About 1' off the foundation of the new building. I'm 4' deep (deep frost line) and hit a concrete cap. Turns out, there was a cistern, from a very old septic. About 6' deep, 2' around. Filled with the most horrible smelling sludge I've ever come across. We missed the thing by about 2" when we dug the footing/foundation for the new addition. Somehow, the fumes were working up through the soil into the crawlspace. We had it pumped out, broke out the bottom, etc., and filled it in with compacted gravel and soil. Solved the lingering smell problem overnight.
Starting to think ground radar is a good thing if I ever break ground again.
Made me think you have no clue what might have been buried under that place over the years. Good luck finding whatever it is.
Sure- Blame Kitty!
.... But before you do, I have one word: Meth. A tell-tale sign of someone making meth, especially with the small-scale, portable, "shake & bake" method is a strong smell of "cat pee." Poor kitty has been taking the blame in countless apartments around.
Still, to be fair, it is possible for cats to cause odor issues. Cats will mark their territory with a smell best described as "skunk lite." If this happened, you'll see little brown dots where the droplets dried. The smell usually dissipates after a week or so, and your treatments should have destroyed it anyway, so this is probably not the cause.
Cat pee, even fairly small amounts, can dry, then ferment in porous materials after a while. This is also what happens to the bodily fluids from a dead animal. The bacteria decomposing the pee will cause a continual stink. It can take "forever" for this to run its' course; your remedies so far would make this problem worse, by slowing it down. You 'speed it up' by exposing the contaminants to air and moisture. Or, you can remove the contaminated soil (or whatever). Sometimes you can identify this contamination with a black light, but not always.
Finally, remember that soil is porous. That is, anything buried can cause a stink several feet away - be it a dead animal or an old oil tank.
I say it's time to stop guessing. Perhaps you can find a lab somewhere that will take air samples, and analyze them for whatever. This might help you identify the cause. Heck, the problem might come from the ground near the place, rather then right under it! Might be worth digging some 'test holes' at various places around the house, just to see if they have the odor. You might even get someone to walk the site with a 'cadever dog' - you never know!
crawl space smell
I am experiencing the same issue in my house (NC). The house was in bad shape when we bought it, there where multiple plumbing leaks and there was actually a pond under the house and mold growing on cinder block foundation and joists. Also the bathrooms and kitchen subfloor and plywood underneath was rotten. I thought the smell was coming from the nasty pressboard type subfloor that was laid on 1/4 inch plywood and was all stained up from many years of who knows what.
I replaced all the plumbing and killed the mold by spraying bleach on affected areas. I then laid 6 mill poly on the ground in crawlspace but did not seal to walls or tape. I also replaced 80% of the pressboard subfloor with 3/4" plywood and installed new tile and carpet in the house. All the walls have been painted and the house looks really nice inside now.
The problem is the smell coming from a part of the house which was an addition that includes a bathroom, laundry, dining and bedroom. The smell is slightly noticable in the house but it also gets into our cloths and anything else that spends time in that area. Its really noticable when we go to a hotel or family's house and pull our cloths from suitcase and they stink!
I am 100% certain the old beams under the additiion are treated with something similair to creasote. I know this because the same beams where used in a shed in the back yard that I ended up tearing down and had the same strong smell. I didn't know this when we bought the house. I don't know what to do about this other than possibly painting the entire underneath of my house which also means removing the blanket insulation. Anyone else been through anything like this and have any success stories?
For the OP's problem (yeah, I know, from 2008), with a rail-side building from the 30s, I wouldn't be surprised if there was an old latrine under or adjacent to the building. But given that the smell is chemical in nature, it's also quite likely that there is soil contamination from chemicals handled in the warehouse. The only two solutions are to completely encapsulate the contaminated soil or entirely remove it.
Any time you deal with any old building there is a good chance that a latrine or cesspool is hidden somewhere, and any time you deal with an old agricultural, warehouse, or industrial building there is significant danger of chemical contamination.