treating mold in crawlspace? (subfloor, roof, dehumidifier, foundation)
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Got some great feedback on crawlspace humidity. Thanks again community!!!
I took at look at what was there, and sure enough there was mold. Attached are some pictures.
I plan to get the problem formally inspected and addressed, but can anyone tell me
1) Though not everywhere, there is mold (see pictures), is this a fairly typical or scary amount of mold?
2) I didn't see any mold anywhere else in the house, but should an typical inspect look elsewhere in the house for mold too? Attic? Vents?
3) What is involved with a typical remediation? Chemicals? Replace existing barrier? Tear out insulation?
4) Is there any safely concerns my family for chemicals used?
5) Should I be aware of something to be sure is done the "right" way?
6) Assuming a dehumidifier & closed crawl are near future consideration (but not part of remediation) , for a roughly 1200 sqft crawl, what might one pay for ballpark? (I am not confident enough in my abilities to do myself)...My Realtor gave me a ballpark of 3K.
I sent you a private message. I can walk you through all of this.
That is a moderate amount of mold but it can certainly be dealt with. Cost would be dependant on your comfort level. If you cure the moisture source, it goes dormant and some people are fine with that. Others want it treated like nuclear contamination however. Of course, many mold remediation companies trend towards seperating you from as much of your money as they can.
Last edited by sacredgrooves; 06-02-2011 at 08:02 PM..
Living in Southern AZ, I have a furnace/AC unit in the attic crawlspace above my laundry room (common placement here). Condensation from the unit is supposed to flow outside the house via a pipe, with excess being collected in a safety pan below the unit that is drained into a second pipe (water from both goes out onto the side yard space and just evaporates in short order).
Problem was, unbeknownst to me, the pan shifted slightly so the main pipe wasn't being used, and during the hot summer the water collection in the pan was too much for the secondary pipe. The overflow flooded the crawl space and the water drained downward. But it drained inside the closet of a guest bedroom so I only recognized the problem when I noticed the carpet outside the rarely used closet was wet.
I won't bother to detail the damage and expense, but the upshot was, even after the repairs were supposed to be finished, a mold problem appeared in the overhead air ducts. I might have never known, but being an allergy sufferer, I'm on a contract with a company that cleans the ducts on a yearly basis. Luckily they found it before the mold had grown much (they didn't even know about the flood) and they initiated remedies. They've been back a couple of times since then to keep an eye on the situation and supposedly we're mold free. I now have a auto-shut-off alarm on the AC unit that will operate if any significant water collects in the pan, so they don't think the mold will reappear. Having lived in back East for many years, I know the dangers of mold and was very glad this was caught before problems arose. Next to my bug company, I love my ZenAir guys the most. So if you're worried about your mold having traveled to your air ducts, get one of those duct-cleaning companies to look. As home services go, they're not too expensive and it's good, for many reasons, to keep ducts clean.
Why is there insulation between the floor joists? That is just asking for mold....I bet you will find a lot more underneath all that insulation, as it will act as a sponge as all the water vapor from the dirt floor migrates up into the air conditioned space of your house. As for encapsulating the crawl space, I am a big supporter of this and there are two ways to do it....one is to do the 20mil vapor barrier, sealed seams, over the entire floor and partway up the foundation wall + dehumidifier. If you have water intrusion that you can't fix with grading outside the house, you will also need to add an interior perimeter drain to a sump pump. If you do all of this, you could be looking anywhere from $5k-8k. Another way to encapsulate is using spray foam insulation (probably closed cell to keep moisture from penetrating) on the underside of your subfloor, between all joists. This too will cost a lot b/c spray foam can get pricey. I'm not 100% sold on the spray foam method but it seems like it makes sense.
As for the mold itself, it's not a terrifying amount. Like above said, it should go dormant if you encapsulate, thus not releasing the spores into the air...but you can always have a mold inspection done anyways to take air samples and use thermal imaging cameras to spot any moisture intrusion in other parts of the house.
1 - You can't see from the pictures how widespread the problem is but I would suggest you poke around the moldy area with a pen, a butter knife or a metal rod to make sure there is no structural decay of floor joists and any other wooden structures.
2- You should have the attic inspected as well. Because of a physics phenomena known as the "stack effect" (you can Google it), air is being consistently sucked in from the lower levels of the house (your crawl space) and escaping through the upper levels (your attic). That air is carrying mold spores and moisture as well. Your family is breathing it, your attic is being exposed to it.
3 - In a typical crawl space cleanup, they will discard and remove all the insulation (which, being damp and/or moldy is useless anyway because fiberglass loses R-Value when wet), replace wood that is rot, apply an anti- fungal and leave it at that. However, if the source of moisture, which is causing the mold to grow is not eliminated, the mold might and most likely will come back. I strongly suggest you consider crawl space encapsulation instead of just mold mitigation, for a number of reasons I will explain later.
4 - Toxicity will depend on what kind of products they are using, so if you are going that route, make sure you get the all the facts and product information. Google them, do your homework. Remember the "stack effect"? It will carry the chemical fumes indoors as well.
5 - If you call a good crawl space encapsulation company, they will clean up the mold, apply anti fungal if necessary and if you so chose, all in the same job, probably for less that you would pay to do this job separately. (one crew, one company, one cost) I actually see no reason for you to do it separately. Even if there is a budget concern, reputable companies have flexible payment options.
In addition, the encapsulation will pay for itself rather quickly in terms of energy savings (and average of 20% savings in cooling and heating costs, much more if you have ducts running through the crawl) , which is why it is the crawl space treatment method recommended by the US Department of Energy, and just about every reputable green building and building science organization.
6 - I can't give you a ballpark because this type of work will typically be tailored to your needs and budget. But good companies will inspect and produce an actual written estimate for free.
Location: Visitation between Wal-Mart & Home Depot
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Quote:
Originally Posted by timd2010
Hello All,
Got some great feedback on crawlspace humidity. Thanks again community!!!
I took at look at what was there, and sure enough there was mold. Attached are some pictures.
I plan to get the problem formally inspected and addressed, but can anyone tell me
1) Though not everywhere, there is mold (see pictures), is this a fairly typical or scary amount of mold?
2) I didn't see any mold anywhere else in the house, but should an typical inspect look elsewhere in the house for mold too? Attic? Vents?
3) What is involved with a typical remediation? Chemicals? Replace existing barrier? Tear out insulation?
4) Is there any safely concerns my family for chemicals used?
5) Should I be aware of something to be sure is done the "right" way?
6) Assuming a dehumidifier & closed crawl are near future consideration (but not part of remediation) , for a roughly 1200 sqft crawl, what might one pay for ballpark? (I am not confident enough in my abilities to do myself)...My Realtor gave me a ballpark of 3K.
I'm certainly not saying that there is no possibility that you have mold growing down there, but that could be dust adhering to sap expressed from your framing.
5 - If you call a good crawl space encapsulation company, they will clean up the mold, apply anti fungal if necessary and if you so chose, all in the same job, probably for less that you would pay to do this job separately. (one crew, one company, one cost) I actually see no reason for you to do it separately. Even if there is a budget concern, reputable companies have flexible payment options.
In addition, the encapsulation will pay for itself rather quickly in terms of energy savings (and average of 20% savings in cooling and heating costs, much more if you have ducts running through the crawl) , which is why it is the crawl space treatment method recommended by the US Department of Energy, and just about every reputable green building and building science organization.
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I can vouch for the energy savings. We had our crawl encapsulated in September and I noted probably 10% lower gas bills this past winter, which is probably skewed low b/c this winter was much colder than usual and gas prices were higher, so it probably was closer to 20% savings in reality.
I then got my kids old little reg wagon, a wire brush, a mask, a old hat and I sprayed the whole beams and floor boards. Then I used a wire brush where mold was tougher and scrubbed.
Next day I did again on remaining areas.
Final day used some plain old bleach. Bleach is not great at killing mold but good at removing stains from dead mold.
Left installation off for a few weeks and ran my regular humidifier, then replaced insulation.
One neighbor who had a newer house the "new wood" soaked up water like a sponge when damp after he did the mold remediation he got a paint sprayer and actually painted crawl space roof with oil paint. Mold wont grow on it.
Years ago in beach towns they used wood from old ships and boats for lumber in crawlspaces in beach towns. You notice a wooden boat gets no mold. Wood gets harder and tougher as it ages. One neighbor who had a new extension (only 20 years old) had to replace all the wood. My 60 year old wood it was surface only. New unseasoned wood in a damp area is prone to mold .
The skill level is near zero to do this. BUT use the more expensive chemical from Home Depot, do not use Bleach as doing a ceiling Bleach will drip on you, could blind you and the smell could over welm you. It is cheap however, the better chemical you can actually touch it as only dangerous if you eat it. The Bleach is just for the final step to remove any stains from now dead mold in small amounts.
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