Thread: substructure mold

I have had several companies inspect my crawl space and tell me the white substance on my floor joists is mold. I was wondering if someone could tell me the best way to kill and or remove it. I have heard of using bleach and water mix or commercial chemicals. Looked at Lowe's but everything said for nonporous materials. I need to treat the structure so I can install new vapor barrier. Also planning on installing humidity fans in the vents to move air and or use a dehumidifier. Any advice would be helpful. Thanks

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Most of the home centers sell mildicides that can be used for cleaning. Nothing beats just getting in and wiping down everything. If you want to go to the next level you can have a local mitigation company fog the entire area.

Hi,

Here are the steps that I would take if it were my home.

1) remove all debris from the crawl
2) roughly level the dirt floor of the crawl
3) inspect the perimeter walls for cracks and have them repaired
4) make sure your gutters and downspouts are not leaking and are draining at least 6 feet away from the structure to a well drained area
5) make sure your grading around the perimeter of the home is sloped appropriately away from the structure
6) install a heavy thick plastic vapor retarded with overlapped and taped seams. run the vapor retarder up the perimeter walls of the foundation and secure it to the concrete stem walls with wood lath and tapcons or equivalent
7) cover the vapor retarder with a couple inches of small rounded gravel aka pea gravel
8) insulated the stem walls aka perimeter foundation walls with 1.5" or 2" of extruded polystyrene rigid board insulation. you can use tapcons and fender washers to keep the rigid board tight against the stem walls. cut neat blocks of rigid board insulation and fit them into the rim joist channels; seal the edges of those neatly cut blocks of foam with spray foam or caulk
9) take your wife on a tour of your newly renovated crawlspace and get ready for the sparks to fly cuz you'll be a hero!!

- - - Updated - - -

Ooops! I forgot about the mold which, in reality, is only a symptom of the moisture problem and is not the real issue.

10) go to home depot and buy Concrobium mold killer and borrow their fogger. follow the label instructions and fog the heck out of the mold. once you've finished killing the mold dry the crawlspace out with a dehumidifier and air mover.

The last fellow wrote this:

10) go to home depot and buy Concrobium mold killer and borrow their fogger. follow the label instructions and fog the heck out of the mold. once you've finished killing the mold dry the crawlspace out with a dehumidifier and air mover.

Concrobium isn't a mold killer; it's designed to be an encapsulant. What that means is that it is intended to put it into a 'capsule' of chemicals to prevent its' growth. I know, right? Ok, I admit I really oversimplified and embellished a little.

Fact is, if what you've got IS in fact mold, you really have only 2 options:

1.) test to see if it's toxic
2.) remediate to a safe level

You can get test kits to take to a lab from Home Depot. Bit expensive but at least then you know what you're dealing with and can investigate further options.

Remediate:

This is tricky. Don't disturb it unless you can for sure keep all the mold SPORES from entering your living space. That means poly off any access points, furnace/ducts for entrance into home, and introduce negative air pressure to blow any spores into the outdoors.

If the area is large, greater than 10 ft^2, you would do well to call a NAMPA guy, that's North American Mold Proffessionals Association, forgive my phone.

Alternatively, there was some research done by some smart guys and they took military testing and made it work, I condensed it, I built a home in an area with a high water table over the past 3 years. I sprayed it with the solution I'll give you the recipe for and granted, it's all treated wood, but didn't have a sump hooked up for almost a full year and still NO MOLD!

Also, while the last guy had some good points, crawl space, slope to one area, just like a wood bsmt, dig a hole, fill with gravel, put in a sump basin and a sump pump. The basin can be as simple as a bucket with holes smaller than the gravel you bury it in.

Drainage away from house for sure, preferably with clay and then topsoil, but good clay not the silty stuff.

Here's the recipe, put it all in a large pot, let it heat until all the crystals have dissolved then spray.

You can find it on the Internet by googling borate solution or 'chemotherapy for wood rot'

I'll explain how it works after the recipe:

Borate solution

750 g boric acid (ant killer)
5 cups borax (laundry booster)
1-Ethylene glycol (car antifreeze)

The way it works is you take the solution and using it at a 2:1 solution of water to borate, spray it on the suspected areas. Ethylene glycol is hygroscopic meaning that it is attracted to water. So when this is sprayed on, the water is absorbed and then the borax/boric acid is drawn into the wood/porous material by the ethylene glycol.

Something many people either do t know or understand is that the mold you see is like the flower of a carrot. What you see are the green leaves but the things growing beneath the surface. That's why products like bleach or just scrubbing don't work well. Planing and sanding aren't good ideas either because molds natural self defence mechanism is to release its' spores and try to develop new host environments. That's why to not disturb it until you are ready. As a precaution, if you are really concerned, I would still poly off/tape areas where spores could be released into the home, also you could use a fan. Wear a mask.

One last thing, the previous fellow mentioned the cold fogger rental. Another product is an air scrubber, it will actually remove any airborne spores from the air inside your home or the crawl space. It would make sense to run it afterwards at least.

By the way, this is all assuming the first guys were right. Out here, we have very alkaline soil. When the ground dries, it looks as white as snow and is as dusty and crystalline as sugar or salt. It would be worth it to post some photos as well. In the off chance you have alkaline soil, I'd really recommend testing first.


Let us know what you do and what your results are. You can contact me directly at tim.devries@yahoo.ca if you need.

Blessings

You might start here first; Mold Remediation in Schools and Commercial Buildings | Mold and Moisture | US Environmental Protection Agency
Remedy the reasons for the mold first then attack the mold.

Not trying to burst any ones bubble, but as a certified mold professional, Indoor Environmental Professional and a well established expert on the subject, the advice given in responses to your question about mold and mold removal are not entirely accurate. For one, you NEVER try to "kill" mold, it is a fungus and as such will survive the worst of scenarios. Mold removal using all of the concoctions mentioned as well as concrobium as a "removal tool" are taboo in the industry and are not proven or effective methods. The mentions of correcting the moisture issue is excellent advise, however you still need to remove the present spores AND roots from the surfaces or they will go dormant after the moisture corrections and then release spores and continue to reek havoc on your air quality. Remember, an old dry dormant spore has the same toxigenic and allergenic characteristics as a brand new wet spore from an active growth site.

The Borax solution as well as all those products you see that claim to "kill" mold are a joke, they only expose homeowners to the chemicals as well as extreme spore release and in most cases end up making you as sick or sicker as if you would have just licked the molds off the surfaces. Follow the IICRC S520 Mold remediation standards and fully REMOVE the mold to include the roots while under massive air control to prevent spores and roots form getting into living areas or creating health issues to the workers. There are several methods of removal available, physical wire brushing, grinders with wire wheels, commercial Hydrogen peroxide removal, soda blasting, etc... However the best method is case by case and can only be decided by you or a professional remediator. Bleach has no business anywhere near a mold project, it kills bacteria, not mold! I also advise you have pre and post testing done of the air quality in the crawl, adjacent living area and a control. If you doing the work yourself and create an air quality issue then its all on you, however if you pay to have the removal done then the pre testing will give you a baseline to hold the remediation company too if they screw up and create an air quality issue. The post testing would show this error and it is then their problem for the cost of cleaning you entire living area. I could go on for an hour, I don't know what part of the country you are in, but there are standards in place in this country and only a fool doesn't follow them.

Oh ya, another point: The EPA information is great for the average Sunday cleaning of a home and they do not recommend testing at all! I have personally spoken with a regional supervisor for them and he stated the info is very vague and they will never get detailed as they have no control over commercial applications to mold issues. He also stated the testing portion of their recommendation is related to those test kits you can buy from Lowe's, home depot, etc.., they are a petry dish that tells you literally nothing and area complete waste of your money. If you log onto their site you will notice the newest language that states "Sampling for mold should be conducted by professionals who have specific experience in designing mold sampling protocols, sampling methods, and interpreting the results. Several problems can occur when sampling.".
Chapter 3 | Mold Course | US Environmental Protection Agency

Feel free to contact me or view our website if you have any questions, I would rather spend time helping you than ever see someone get sick from improper remediation activities.

Pat.

Thanks for the corrections.i didn't k ow all that

Thanks Tim, as I said I don't try to argue or burst bubbles, just try to help people understand where the industry has gone with mold and mold remediation. Your information about testing, remediating, keeping it out of the living area, etc.. is correct, it's just the part about "killing" molds that has been repeatedly proven to be incorrect. It's not anyone's fault when they relay the info they have been told for so many years, it has been what was thought to be true for many many years and education to correct the information is very slow coming.

We have learned more about mold in buildings in the past 5 or so years than mankind has known in all of time, it is an ever advancing industry with a LOT of confusing and misguided information available on the internet. The EPA information is very vague and misleading by no fault of theirs, it is a government agency trying not to create legal issues yet publishing information on a subject they have no control over (and hopefully never will). With things like lead and asbestos they can put it right out there, there are laws and established levels to follow, however with mold it is a whole different ball game and they cannot be specific as they do not have a spine in the game to stand straight and tell us what we will or will not do!

Not to forget I think the biggest urban myth I have ever learned about is that Bleach kills mold, simply not true and proven time and time again. An instructor for an IICRC class once stated "you are more likely to get sick from the bleach than if you just licked up the mold"! Obviously a play on words but the point is well taken.

The hardest thing about being the IEP on mold projects is correcting all the bad info and bringing the hype about mold back down to reality. Then once all of that is cleared up we can get on with the remediation project. I DO NOT do remediation, I am the beginning and end of the project as the Environmental consultant and tester. However, I have been the consultant and oversight on thousands of remediation projects and have seen the goods as well as the bad's. It is a learning process for all of us and I highly doubt we have solved the mystery about mold and mold remediation just yet, there is still evolving science and studies in place as well as many more to come.

Like I said, feel free to consult our online info for resources or links to more information, I follow some of the leading experts in this industry and post their blogs and articles as well as our own blogs, articles and info on different sites. Our web page and our Facebook page have lots of good information from credible peer reviewed resources. The most updated is probably our facebook site, it is much easier for me to keep up with.

web: Home
facebook: Advance Look Building Inspections & Environmental Testing

Hello Steve Owens,

Normally this type of conversation gets shot down before it has gone this far.
Why are you concerned with mold in your crawl space? The mold was there before the house was there and will be there long after it and you are gone.
You likely do not have a mold problem, you have a moisture problem.
Get the moisture under control and the rest of the issues will also be taken care of.
If you have damaged lumber or other materials then remove and replace. Cleaning and "killing" mold beyond that is pretty useless unless you are living down there or you are concerned about reselling the property. Concern about reselling is more about perception than reality since some "expert" may convince the next owner that it is imperative to "remediate".
There is absolutely NO need to test the mold, you can see it and know you have it and what specific type of mold is immaterial unless you are allergic to mold and know the specific type.
Testing for mold just lines the pockets of "mold is gold" testers.

We need some truth here.
Not pseudoscience.
Check this if you want more information.
Forensic Applications Consulting Technologies, Inc. - Mold ("mould")

Where are you CaoimhÃ*n P. Connell?

Originally Posted by Jim Luttrall

Hello Steve Owens,

Normally this type of conversation gets shot down before it has gone this far.
Why are you concerned with mold in your crawl space? The mold was there before the house was there and will be there long after it and you are gone.
You likely do not have a mold problem, you have a moisture problem.
Get the moisture under control and the rest of the issues will also be taken care of.
If you have damaged lumber or other materials then remove and replace. Cleaning and "killing" mold beyond that is pretty useless unless you are living down there or you are concerned about reselling the property. Concern about reselling is more about perception than reality since some "expert" may convince the next owner that it is imperative to "remediate".
There is absolutely NO need to test the mold, you can see it and know you have it and what specific type of mold is immaterial unless you are allergic to mold and know the specific type.
Testing for mold just lines the pockets of "mold is gold" testers.

We need some truth here.
Not pseudoscience.
Check this if you want more information.
Forensic Applications Consulting Technologies, Inc. - Mold ("mould")

Where are you CaoimhÃ*n P. Connell?

I am in McDonough Georgia. My plan is to put a dehumidifier down there and redo the poor job that was done on the vapor barrier. I intend on spaying the mold with concrodium, just to make me feel better. I was wondering if I need to seal the vents or leave them open or add one or more of the humidity fans. The mold is white. I took pics but can't figure out how to attach them.

Originally Posted by Steve Owens

I am in McDonough Georgia. My plan is to put a dehumidifier down there and redo the poor job that was done on the vapor barrier. I intend on spaying the mold with concrodium, just to make me feel better. I was wondering if I need to seal the vents or leave them open or add one or more of the humidity fans. The mold is white. I took pics but can't figure out how to attach them.

Go the Building Science Corporation for information on crawl spaces.
BA-0401: Conditioned Crawlspace Construction, Performance and Codes

Here is a quote from Dr. Joe Lstiburek when discussing top 10 dumb things builders do in the South:
"Crawlspaces are real simple to understand and deal with. When you vent crawlspaces you bring in hot, humid air and cause moisture and mold problems. The ground surface is typically colder than the dew point temperature of the exterior air. The underside of crawlspace floor insulation is radiation coupled to the ground surface and is very close to the same temperature of the ground. Moisture droplets can be seen all over the top surface of typical polyethylene ground covers as well as hanging from the bottom surface of the crawlspace floor insulation. Gee, I wonder how all the water got through the poly ground cover? It must have leaked through the walls. Give me another break. Now, when the moisture is in the insulation where do you think it wants to go? Where is the air conditioning? Moisture moves to the cold surface. Venting crawlspaces made sense only when you had no air conditioning and no insulation and no crawlspace walls."


Before doing anything or allowing anyone else to do anything, I would try to get a good understanding of crawl spaces and the science behind ventilation, dehumidifying, etc.
You can't really ventilate AND dehumidify. and you can't really install "humidity fans" if you live in an area with high humidity when the a/c is running. When you mix systems, you can make bad things worse or create problems where you had none.

A lot depends on your local weather and house construction, age, etc. since a "one size fits all" approach won't work with crawl spaces.

Steve,
You can be forgiven for not being sure what to do. Even the experts disagree on mold remediation. If the framing members are intact (you can't push a screw driver into the moldy areas) then a topical treatment may make you feel better, but lowering the crawlspace humidity is the only way to convince the mold to go dormant.

Around here, we don't need dehumidifiers, but we do seal the crawlspace floor to the walls and penetrations to make the crawlspace part of the conditioned space. The crawlspace is not ventilated. In Georgia, I guess that with high relative humidity, even a sealed crawlspace floor will still have high humidity in the crawlspace area, so putting a dehumidifier in after you've sealed the floor may help. But your ac will be lowering the humidity in the home, so a dehumidifier may not be necessary, once the space is sealed. You might see what some of the area builders are doing. Preventing mold has become a huge liability issue for builders and most are trying to employ the latest and best practices to prevent it.

If your concern is more with spore release, then spaying a stain killer like Kilz on the framing may be better than some mold inhibitor.