# MOLD found on Wood Subfloor under Fridge-HELP!!!



## Gary in WA (Mar 11, 2009)

Welcome to the forums!

I would not use household bleach/water around my kids or my lungs. Abate it with laundry soap/water first, wearing a respirator if possible: http://www.toxic-black-mold-info.com/moldclean.htm

Keep the area contained and the kids away; http://www.buildingscience.com/documents/reports/rr-0210-mold-remediation-in-occupied-homes

Moved you for more responses.

Gary


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## Maintenance 6 (Feb 26, 2008)

Since you've already opened this up, you now have mold spores travelling around the air in your house. Lots of them. First thing is to wet it down with a detergent solution and scrub it as best you can. If possible put a window fan in place and exhaust the air to the outside while you work. Wear an N95 rated respirator. When you have scrubbed everything off that will come off, then let it completely dry. Evaluate the material that was moldy. If it is solid and has not been compromised by the moisture, then you can treat it with a fungicide. If it is permanently damaged and can't be salvaged, then replace it. As far as fungicides, there are some commercially available that are effective as is a 10% bleach solution. As far as bleach, DO NOT exceed 10%. No fungicide is particularly effective at penetrating porous materials, regardless of what they may claim. Keep your ventilation in place while you treat. When everything has completely dried, seal the area that was effected with something like Kilz or Zinser. This will lock down any stray spores and mold fragments. Absolutely the most important thing is to figure out what caused the moisture problem that allowed the mold to thrive in the first place. All of your work will be for nothing if you don't eliminate the moisture. Scrub, Dry, Treat, Dry, Seal. Go 12" past the last signs of mold. The final effectiveness of your work is related to your diligence in carrying it out.

P.S. Laundry detergent would fall close to the bottom of my list of cleaners. Use Lestoil, Top Job or Lysol. If you don't have any of those, then dishwashing liquid would come next.


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## oodssoo (Jul 16, 2012)

Yes. Do what he says!

How big is your entire kitchen floor?


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## krissyp19 (Dec 10, 2012)

Thank you for your responses. It is a 3'x3' area, only under my fridge. It was suggested to go to Home Depot and buy a spray bottle of some sort of Mold killer. We are going to replace the entire piece of infected wood.


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## ccarlisle (Jul 2, 2008)

Well, not once did you mention what you plan on doing to prevent further mold problems - and that, to me anyway, is step #1. May be an icemaker leak or a faulty pan if your fridge has one. Either way, check the leak first before you go and replace the subfloor.

That's probably "Concrobium' from HD that you are talking about - a mold killer...not bad a choice compared to, say, bleach. Leave it on to dry...


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## carpdad (Oct 11, 2010)

Mold is found everywhere. It's in the air all the time. If that is all you found in the house, you don't have to panic.
I read that vinegar will kill the spores.
In addition to already listed water source, frige defroster drain may be blocked or the tub under it may be overflowing. It is possible that refrigerator is not level and defrosted water is not draining properly. It happened to me.
Check the ice maker for water supply connections inside and outside, also.


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## jagans (Oct 21, 2012)

*Dont Panic*

This is the new panic button for Lawyers, and its a load of Bull

Just open the windows, take household bleach at 3 to 1 with water in a pump sprayer and spray the d--- mold, and you will watch it disappear. Then fix the leak. I don't know why everybody makes such a big deal out of mold, its all around us all the time. Oh yeah, I do know why. Its because the Lawyers ran out of Asbestos cases.

HONEST, THATS THE TRUTH. I have been to several pro seminars on mold and that is about the size of it. 

Now its a different problem if you have a dew point problem and chronic mold, but that is much different than a leaky fridge pan, or ice maker line.

Give the poor lady a break.


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## krissyp19 (Dec 10, 2012)

Thank you Jagans. Was not looking for any judgement on my end. Strictly asking for advice on how to treat Mold until I'm able to remove the diseased wood. Obviously my 1st PRIORITY would be to find the culprit-didn't think I needed to give an explanation on that. Thank you to everyone who did give positive feedback. The area is currently sprayed with a Mold spray & am letting it dry! Thanks again!


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## Dean CRCNA (Jan 24, 2010)

Krissy,

I know you like the feel good answer that jagans gave you, but GBR & Maintenance 6 gave a lot better advice.

Just for future reference ...

1. Dead spores are many times just as dangerous as live spores. Live spores hang on to the substrate more than dead spores, which go floating in vast numbers into the air. You were better off leaving the mold alive.

2. Bleach and such doesn't kill the mold on porous surfaces. It does kill the flower part of the mold, but not the stem and roots. In fact, you may have given the roots what they were craving ... water.


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## jagans (Oct 21, 2012)

*Mold*

I never meant to imply that mold is never a problem. Where buildings are designed wrong wherein water is developed in the presence of water, heat and organic matter, a chronic problem can occur. This became a very big problem in the southern states where motels with vinyl wallpaper applied with wheat based paste were air conditioned, and the dew point fell right behind the vinyl wallpaper. The use of high grade vinyl wallpaper raised the ratings of the motels and hotels, so they insisted on its use. Extensive mold problems were the result. 

This young ladies problem is not like that. This is a one off leak, in a small, isolated case. Killing with bleach and water, and making sure that the leak is solved, removing the molds ability to live, and replacing the subfloor,_* if *_it is rotten will solve her problem. 

As I said in my previous post, we have been living with mold since the beginning of time. They are part of life. The last thing this country needs is another carcass for the lawyers to chew on, but that seems to be the way things happen here. We regulate based on Mania to the point where we scare everybody for no reason. How many people die from stress related issues compared to mold related issues?


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## Maintenance 6 (Feb 26, 2008)

FWIW, Sodium Hypochlorite (bleach) will not only kill mold, but will disolve the glucan bonds that hold the cell walls together. And it only takes 2.4% concentration to do it and less than 5 minutes of dwell time. That means that the mold is not only dead, but has been broken down to it's component parts to an extent that it is not even considered an allergen. Never exceed 10% concentration of bleach. Breathing chlorine and chloroform compound gases is far more dangerous than any of the stuff that mold produces. Dead mold spores and mold fragments can still be allergens to some people, that is why you need to clean up the mold, then treat it and finally seal it to lock down any stray fragments or spores.


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## Gary in WA (Mar 11, 2009)

Does anyone have anything more current than this 10 year old study of bleach on Doug-fir?

http://ir.library.oregonstate.edu/x...ff.Forestry.AbilityBleachOther.pdf?sequence=1

Thanks, Gary


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## Dean CRCNA (Jan 24, 2010)

Maintenance 6 said:


> FWIW, Sodium Hypochlorite (bleach) will not only kill mold, but will disolve the glucan bonds that hold the cell walls together. And it only takes 2.4% concentration to do it and less than 5 minutes of dwell time. That means that the mold is not only dead, but has been broken down to it's component parts to an extent that it is not even considered an allergen. Never exceed 10% concentration of bleach. Breathing chlorine and chloroform compound gases is far more dangerous than any of the stuff that mold produces. Dead mold spores and mold fragments can still be allergens to some people, that is why you need to clean up the mold, then treat it and finally seal it to lock down any stray fragments or spores.


Sure … bleach kills mold when it can reach the root, steam and flower, like on hard surfaces. Anti-freeze will also do this along with 100s of other products. The problem comes with it working on porous surfaces. Anyone who has ever tried to get rid of mold in their shower by using bleach and is frustrated at the inevitable return of mold within a very short time, knows that bleach does not kill mold on porous surfaces. 

Many falsely assume that it works, because they remove the moisture problem … pour bleach on … and the mold problem ends. However, if you continue the moisture source … pour bleach on … the mold will return. This is because the bleach did not reach the roots and thus … did not really kill the mold after all. It is the removal of water that does the trick. Not using bleach.

EPA, CDC & OSHA use to recommend bleach, but they even have wised up and have removed bleach as a problem solver.

Just my 2 cents


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## krissyp19 (Dec 10, 2012)

I appreciate everyone's responses. The Area where the Mold is/was is being completely replaced on Saturday. I'm sure if it was severely bad all 4 of us would be showing respiratory symptoms. Thanks again! Will post final picture of Tile floor!


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## Maintenance 6 (Feb 26, 2008)

GBR in WA said:


> Does anyone have anything more current than this 10 year old study of bleach on Doug-fir?
> 
> http://ir.library.oregonstate.edu/x...ff.Forestry.AbilityBleachOther.pdf?sequence=1
> 
> Thanks, Gary


Here's the short version. 

http://www.jacionline.org/article/S0091-6749(04)00083-1/abstract

The full study is available from the University of Arizona.


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## Maintenance 6 (Feb 26, 2008)

Dean CRCNA said:


> Sure … bleach kills mold when it can reach the root, steam and flower, like on hard surfaces. Anti-freeze will also do this along with 100s of other products. The problem comes with it working on porous surfaces. Anyone who has ever tried to get rid of mold in their shower by using bleach and is frustrated at the inevitable return of mold within a very short time, knows that bleach does not kill mold on porous surfaces.
> 
> Many falsely assume that it works, because they remove the moisture problem … pour bleach on … and the mold problem ends. However, if you continue the moisture source … pour bleach on … the mold will return. This is because the bleach did not reach the roots and thus … did not really kill the mold after all. It is the removal of water that does the trick. Not using bleach.
> 
> ...


The true fact is that the bleach works just fine. What you have to realize is that in a shower you have a mold incubator. You have temperatures in the perfect range. You have perfect moisture levels, and you have the fatty acids in soap scum which is perfect gourmet mold food. You can kill the mold and it will return, because mold spores are everywhere and they've got the perfect terrain to regrow. You've grown new colonies from scratch, not regrown the originals. If one reads the fine print, none of the commercially available fungicides garantees performance on porous surfaces. It's a fact of life (at least fungal life) that mold send mycelia (roots if you will) deep into porous materials where few things can penetrate without having a severely adverse effect on the base material. I have yet to figure out why people continue to want to hold up the EPA and OSHA as experts on mold remediation. Niether agency has ever done any comprehensive studies on killing mold. The EPA's charge is to protect the environment, not tell you how to kill things that live in it. And OSHA's charge is to protect workers. The extent of their involvement with sodium hypochlorite is to make sure mold remediators aren't breathing any toxic fumes. They couldn't care less whether it kills mold. As far as the CDC, they have done studies and even recommended bleach as a sanitizer in healthcare environments, not only to kill mold, but most every other microbe imaginable, including staph and HIV. Again with the same precautions, 10% is enough. 
So..... if you are not comfortable with bleach then use one of the hundreds of other things that will kill mold. Just be careful, because things like sulphuric acid or gasoline can cause you a lot more problems than the mold ever would have.


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## Dean CRCNA (Jan 24, 2010)

Maintenance 6 said:


> The true fact is that the bleach works just fine. What you have to realize is that in a shower you have a mold incubator. You have temperatures in the perfect range. You have perfect moisture levels, and you have the fatty acids in soap scum which is perfect gourmet mold food. You can kill the mold and it will return, because mold spores are everywhere and they've got the perfect terrain to regrow. You've grown new colonies from scratch, not regrown the originals. If one reads the fine print, none of the commercially available fungicides garantees performance on porous surfaces. It's a fact of life (at least fungal life) that mold send mycelia (roots if you will) deep into porous materials where few things can penetrate without having a severely adverse effect on the base material. I have yet to figure out why people continue to want to hold up the EPA and OSHA as experts on mold remediation. Niether agency has ever done any comprehensive studies on killing mold. The EPA's charge is to protect the environment, not tell you how to kill things that live in it. And OSHA's charge is to protect workers. The extent of their involvement with sodium hypochlorite is to make sure mold remediators aren't breathing any toxic fumes. They couldn't care less whether it kills mold. As far as the CDC, they have done studies and even recommended bleach as a sanitizer in healthcare environments, not only to kill mold, but most every other microbe imaginable, including staph and HIV. Again with the same precautions, 10% is enough.
> So..... if you are not comfortable with bleach then use one of the hundreds of other things that will kill mold. Just be careful, because things like sulphuric acid or gasoline can cause you a lot more problems than the mold ever would have.


OSHA

OSHA has some very good info on mold. In fact, we had to study it when I went to mold school. They specifically state that bleach is not recommended. Additionally, they say; “_As a general rule, simply killing the mold, for example, with biocide is not enough. The mold must be removed, since the chemicals and proteins, which can cause a reaction in humans, are present even in dead mold”_. 

CDC

_Mold growth can be removed from *hard surfaces* with commercial products, soap and water, or a bleach solution of no more than 1 cup of bleach in 1 gallon of water._ Not on porous surfaces.

EPA

EPA also has a lot of information on mold, including a booklet that many "trained" remediation companies follow. We also studied their info when I went to mold school, so I could pass several test on the subject. They say; _"Biocides are substances that can destroy living organisms. The use of a chemical or biocide that kills organisms such as mold (chlorine bleach, for example) is not recommended as a routine practice during mold cleanup"._ 

Not really trying to argue the point. Just was trying to help other contractors, who are interested. I will butt out.


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## federer (Aug 20, 2010)

it would be cool if you post before and after pics!


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## Ed911 (Oct 15, 2011)

Perhaps reading this information...about Tilex Mildew Root Penetrator and Remover...which uses beach as an active ingredient will help. Just remember, that the bleach used in household products is very diluted...and safe if used as indicated.

It appears that application is the key to killing mold...5 to 10 minutes depending on the surface, be it porous or nonporous.


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## Dean CRCNA (Jan 24, 2010)

Ed911 said:


> Perhaps reading this information...about Tilex Mildew Root Penetrator and Remover...which uses beach as an active ingredient will help. Just remember, that the bleach used in household products is very diluted...and safe if used as indicated.
> 
> It appears that application is the key to killing mold...5 to 10 minutes depending on the surface, be it porous or nonporous.


The only porous surface they say is grout. All other surfaces are hard surfaces. Additionally, they say not to use on wood, which is the original topic. Advertisements are many times different than reality.


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## Ed911 (Oct 15, 2011)

Wood...yep. The only reason that I thought they wouldn't want to use it on wood, is that it might damage it, but in this case...it would be okay...as an off label use since the wood was going to the dump anyway.


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## Gary in WA (Mar 11, 2009)

Any more current from a source other than Clorox company? They are a little bias...

What I have found;

 *"6. Hypochlorites (Chlorox Bleach):* 
Bactericidal, Virucidal, Fungicidal, Sporicidal (prolonged contact time required), and Tuberculocidal. Use a diluted concentartion of  1:10 .
*Advantages -* inexpensive
*Disadvantages -* bleaching agent, toxic, corrosive, inactivated by organic matter; removes color from many interior fabrics; dissolves protein fibers (i.e. wool, silk); has not shown to be effective against stachybotrys spores." Underline is mine, from; http://www.toxic-black-mold-info.com/disinfectant.htm


"*Why Chlorine Bleach is NOT Recommended for Mold Remediation.
*Clorine bleach is corrosive and that fact is stated on the product label (not to mention the exposure hazards of dioxins). Yet the properties of  chlorine bleach prevent it from “soaking into” wood-based building materials to get at the deeply embedded mycelia (roots) of mold. The object to killing mold is *to kill its “roots”.* " Underline is mine, from: http://www.spore-tech.com/viewCategory.asp?idCategory=78


"One reason is that bleach cannot completely kill mold growing in porous materials. The chlorine in bleach cannot penetrate into porous surfaces such as drywall or wood. The chlorine is left on the surface of porous materials and only the water component of the bleach is absorbed into the material, providing more moisture for the mold to feed on.

Some of the mold on the surface might be killed but the roots of the mold are left intact meaning the mold soon returns, leaving you in a cycle of repeated bleaching. Perhaps this is why some people believe that spraying bleach on mold doesn't affect it but instead just bleaches its color so you can no longer see it." Underline is mine, from: http://blackmold.awardspace.com/kill-remove-mold.html

"A recent scientific study paid for by Clorox states that "Chlorine Bleach is NOT registered with the EPA as a disinfectant to kill mold." Unless the mold spores are on top of a hard non-porous surface such as a counter top, bleach is ineffective at killing the mold completely. Instead it will simply whiten it and make it appear to be gone while the fungal "roots" are still alive. Bleach also dissipates quickly, leaving inert (harmless to mold) by-products behind. In fact, over 50 percent of the chlorine ions have leaked through the plastic bleach bottle in just 24 hours after its manufacture. The rest slowly leach out as it sits in warehouses, stores shelves and supply closets. Further, bleach is highly carcinogenic and mutagenic. 
Read more: Ingredients That Kill Mold | eHow.com http://www.ehow.com/list_5799848_ingredients-kill-mold.html#ixzz2FBQSGz8u" Underline is mine, from: http://www.ehow.com/list_5799848_ingredients-kill-mold.html

I found this very interesting- "Active ingredient system" of various mold cleaners; http://www.betterbiltchemical.com/Testing & Comparisons/Product Comparisons - Mold.pdf

Gary​


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## Ed911 (Oct 15, 2011)

No more using bleach on wood. Good article...thanks for posting this information. I learn something everyday...and will pass this along.


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## paintdrying (Jul 13, 2012)

In the near future mold will be broken down through genetic manipulation. Scientists cracked the genetic code of a bacteria known as Mrsa. This is a very significant break through. Let us not forget mold is your friend, with out bottom feeders breaking down organic matter we would all die.


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## Maintenance 6 (Feb 26, 2008)

GBR in WA said:


> Any more current from a source other than Clorox company? They are a little bias...
> Clorox didn't do the study. U. of Arizona did the study.
> Funny that you would say that.......


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## Gary in WA (Mar 11, 2009)

Whoops, my fault. The study was paid for by them. On porous and non-porous ceramic material. Not wood, big difference there. 
Very important to dry the wood to prevent further mold growth; 

The isolation frequencies of the various
fungi do not imply that the boards
were covered with spores or hyphal fragments;
however, the results show that viable
fungal propagules remain on the
wood surface following bleach treatment.
Some airborne spores also may
have landed on the boards as they were
drying; however, regardless of the origin
of the fungi, failure to alter the conditions
on the wood surface, primarily
through drying, will invariably lead to
regrowth of these fungi.

Water and
bleach washes tended to reduce surface
discoloration by 40 to 50 percent (Fig.
1), but obviously they did not kill all the
spores on the wood surface; it is clear
that the fungi remaining on the wood
surface after treatment were capable of
continued growth and discoloration
when the wood was stored under ideal
growth conditions. 

Implications
While bleach is often recommended
for remediation of surface mold on
wood, our results illustrate that the treatment
does not eliminate the surface
microflora. As a result, an important
component of remediation must be drying
to moisture levels below 20 percent
(the generally accepted level for inhibiting
growth of fungi onwood) (Zabel and
Morrell 1992). In the absence of drying,
some fungi clearly survive the treatment
and may re-colonize the surface. (http://ir.library.oregonstate.edu/x...ff.Forestry.AbilityBleachOther.pdf?sequence=1)


To be fair, none of the products tested treated all the mold types effectively. I feel bleach is too harsh on ones lungs and it doesn’t effectively remove all traces of mold, still researching others. Thanks for the link, I couldn’t get the PDF but it was tested on ceramic anyway (great for tile/grout). But we knew that.


Gary


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## Maintenance 6 (Feb 26, 2008)

What you've posted is very much the case. It is also why, when performing a remediation effort, after cleaning and attempting a fungicidal effort, it is very important to seal the surface. This isn't just for aethetics. It is to prevent stray mold fragments and spores from reentraining into the air. No product, regardless of claim by the manufacturer is effective at "killing" mold that is deep seated in porous materials. If possible, affected porous materials should be replaced. In the real world, there are items, such as framing and subflooring that are not easily or readily replaced. They need to be treated as effectively as possible. Bleach does come with it's risks. That is one of the primary reasons that OSHA and the EPA have come out in opposition to it. That is why I ALWAYS recommend that if one is going to use it, they NEVER exceed 10% and always use it in a well ventilated area. People will use it because it is one thing that everyone has under the counter. Of the sites that you posted links to, some have good info, while some are sponsored by "magic mold potion" companies. I have serious reservations about the "Sporetech" site, mainly because he promotes "Mold and Mildew" surveys. A true mold expert would know that mildew is a class of mold that is really only found on the leaves of living plants. (Believed at one time to be caused by the dust from industrial mills in Jolly old England, hence the name MILdew). This one: Ingredients That Kill Mold | eHow.com http://www.ehow.com/list_5799848_ing...#ixzz2FBQSGz8u says not to use bleach, but under the "More to explore" link is a site explaining to use bleach. Go figure. 

Another thing to remember is that mold that isn't "killed" will go dormant when moisture levels drop (usually below .6 water content or 60% RH). As long as moisture levels remain low, it may never become a problem, but in the event the surface is re-wetted, the mold will return with a vengeance.

"A recent scientific study paid for by Clorox states that "Chlorine Bleach is NOT registered with the EPA as a disinfectant to kill mold." That is true, but then, think about what the ramifications are for a product to be registered as any kind of "Cide" (pesticide, herbicide, fungicide). The transportation costs alone would likely triple the cost of bleach, not to mention the red tape that the manufacturer, supplier, and end user would be subjected to.


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## federer (Aug 20, 2010)

well i think she said she cut up the part and is going to put new wood in, so its all good


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## hidden1 (Feb 3, 2008)

Does vinegar or borax(diluted correctly) work on it differently?


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## Maintenance 6 (Feb 26, 2008)

Borax would be a good choice to scrub mold from a surface. Regular Borax would not be my choice for a good fungicide. I don't know if there would be enough borates in it to really do a good job. Boron compounds are used as a preventive treatment. Vineger will kill mold. The acetic acid is what does the job. It would be corrosive. I would not dilute it. It is not the fungicide of choice since there are other things present in vineger that complicate it's effectiveness.


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## hidden1 (Feb 3, 2008)

Thanks for the info.I wondered about them.Was looking for something to use on white vinyl fence that doesnt always get the sun it needs and tends to grow mold.Heard vinegar and borax leaves a bit of a shield siminar to those chemicals in big box stores like mircrobial blocker.I know nothing will stop it totally outside in open,but may help.


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## CRS (Jan 9, 2013)

The best solution for any mold issue is to completely remove it. Any "quick fix" will simply either hid the problem or only remove the surface issue. However the remainder of the mold will still be in the material and continue to grow


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## oodssoo (Jul 16, 2012)

CRS said:


> The best solution for any mold issue is to completely remove it. Any "quick fix" will simply either hid the problem or only remove the surface issue. However the remainder of the mold will still be in the material and continue to grow


Just bleach it and scrub it off, if it is on the outside. Consider doing that as an annual cleaning...


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## CRS (Jan 9, 2013)

By using bleach you will just change the colour of the mold. it will not remove it. That is just a "quick fix" solution. It will not remove the root of the mold in the material and the mold will come back


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## Maintenance 6 (Feb 26, 2008)

CRS said:


> By using bleach you will just change the colour of the mold. it will not remove it. That is just a "quick fix" solution. It will not remove the root of the mold in the material and the mold will come back


You've never really studied mold or done much remediation, have you?


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## CRS (Jan 9, 2013)

If its surface mold, any microbial disinfectants will remove it, but if the mold has grown for a long period and is in the substance of the material, the only way to remove it is by replacing the material


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## Maintenance 6 (Feb 26, 2008)

I agree that mold that has thrived on an organic material will have sent mycellia into the material that cannot be reached by a fungicide, however, there are building components that cannot be easily replaced. If the material is in a place where removal and replacement is impossible, then the mold needs to be treated by cleaning, treating and sealing, with particular attention paid to eliminating the moisture to prevent re-establishment of the mnold colonies. To state that bleach will only change the color, is misleading. There are several effective fungicidal compounds. Phenols, quaternary ammonias and sodium hypochlorite among them.


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