# How to control Mold Part 1



## Maintenance 6

*How to control Mold Part 2*

Clean up
Now, if everything went well, you should be looking at some things that may not be able to be removed. This would be framing, sheathing or flooring and sub-flooring. Check these items to be sure they are salvagable. Mold remediation does not restore rotted wood. Structural parts that are rotted need to be replaced. For those that are in good condition, but have had mold growing on them, either in the past or actively, a cleaning is in order. Many people want to skip this step and go directly to treatment. The two are not the same. Use a detergent solution and a stiff nylon bristled brush to thoroughly scrub all reachable surfaces. Use a wet vac to keep after the water run off. Almost any good household cleaner will work for this. Wipe everything down and discard any rags. Allow these items to dry. If necessary, use dehumidification to speed the process. Cleaning is important to reduce the airborne load of spores and mold fragments.
Kill it!!
Now the controversial and misunderstood part…..killing the mold. Mold is not bulletproof. Many things kill it. Some things that kill it will also kill you. OK, that is a little extreme. There are many good fungicides on the market. Some are hyped as better than others, but the good ones fall into a few categories. Phenols, Quaternary Ammonias and Sodium Hypochlorite (bleach) all kill mold. Most commercial products also include wetting agents to make them penetrate porous surfaces better. My own rule is that if the product doesn’t have an MSDS (Material Safety Data Sheet) listing it’s active ingredients, then I won’t use it. Plenty of companies tout some magic mold killer, but then hesitate to tell you what’s in them. Pass those by. Select a material to treat and follow the manufacturer’s instructions. More is not necessarily better. PARTICULARLY if you choose to use bleach. While it is effective, plain bleach should never be used in concentrations greater than 10%. There is a difference between laundry bleach and industrial bleach. Know what you are using. Bleach also needs a wetting agent to penetrate porous surfaces. Use extremely good ventilation practices, no matter what you use. Do not exceed recommendations, no matter what product you choose. Almost all fungicides are corrosive to one degree or another. No only to you, but to nails, screws wiring, etc. Respirators do not protect you from chemical fumes unless you have the right cartridges. P100s aren’t it. When treating, make certain that all surfaces have been covered. Allow this to completely dry. Hepa vac all surfaces in your contained area.
Seal it
You should now have surfaces that have been scrubbed to remove the surface mold, have been treated to kill anything that was growing at least on the surface and partially below. The final step and another one that most people like to skip, is to seal the surfaces. This is done to lockdown any stray mold fragments that may still be on the surface and to minimize the emission of spores from hidden spaces that could not be reached. It also covers any stains left over. Use a stain blocker for this. Zinssers, Kilz and others will work. There are some products made specifically for mold stains and these include a certain amount of fungicide in their formulation. Not a bad idea, but not really necessary. When the sealer has dried, thoroughly clean up your work area. HEPA vac everything. Take down your plastic and bag it all. You are now ready to reconstruct.
A few extra things:
The idea here is remove and or drastically reduce the number of airborne spores, mold fragments and dead mold carcasses in your home. All of which can be allergens.

Mildew is in fact a parasitic mold that thrives on the surface of living plants. There is no mildew in your shower unless you are growing plants in there.

During work, I recommend disposable coveralls. Take them off before leaving the work area. Put on fresh ones when re-entering.

I have found that there are loads of Magic Mold Killer websites. Some are very crafty in their wording. For the uneducated they can be misleading in how they present mold and their take on how to control it. Mold is Gold, and these people are out to get your gold by selling you something that is not anymore effective than anyone else’s, and in some cases is much less.

Legionella is not mold, it is a bacteria and is treated differently than mold.

Mold does not grow on masonry. It will grow on dirt accumulated on masonry, but the PH of masonry is way out of wack to support mold.

Mold will not grow in water. Therefore it does not grow in toilets. Bacteria will grow in water. It therefore grows in toilets.

OSHA has no interest in killing mold, only in protecting workers.

The U.S. EPA is interested in protecting the environment. Their mold remediation expertise is based more on protecting the environment than killing mold. Read their advice accordingly.

When using a mold remediation company: Be sure that the company is knowledgeable about mold. Many asbestos abatement companies jumped on the mold remediation bandwagon just because the negative airflow and containment processes were similar. Remember Mold is Gold? There is a difference between removing a mineral and killing an organism. Insist on air sampling prior to starting work and the same clearance samples upon completion. These should be taken by an independent company versed in mold sampling. These should include samples taken directly in the suspect area, a sample taken indoors but away from the area and at least one outdoor sample. Compare the results. Upon completion, there should be a significant drop in airborne spores and they should be lower than the outdoor sample. Some companies will try to talk you into flat plate mold tests. Mold spores settle on to a plate loaded with gourmet mold food. Days later, after a colony has grown, they will tell you the results. While it may be fun to know what species of mold has grown, there is little useful information to be gathered from this test. You won’t know the difference between 10 colonies of penicillium and 6 colonies of aspergillus anyway.

Molds are the world’s garbage processors. Without them dead leaves would never disappear. Dead grass and organic waste would not go away and soil would not be replenished by the material that they break down. Mold remediation dates back thousands of years and is mentioned in the Old Testament. 

Hope this is useful information.


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## forcedreno2012

Kudos on a great post.

Excellent easy to understand information. I agree on the sky is falling reaction - one thing that a lot of people down here were doing after Isaac was freaking out about mold when they should have been focusing a leetle more on the sewage issues. 

Again thanks for stressing the sealing. People just tend to wipe things down with bleach etc and then they think they are done. In fact we had a so called remediation company tell us that. The bleach solution will kill the active surface mold on top of wood sheetrock etc but there is still mold *in* the wood. If you don't seal before you cover with sheetrock roofing etc you going to be fighting a losing battle if there is any moisture in the air. 

Curious - what are you thoughts on the dry ice approach?

Robyn


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## Maintenance 6

Thank you for the comments.
Dry ice is effective and I have used it in places where water couldn't be used. Under side of a framed roof in a really old historic house and on the floor joists in a crawl space for example. Set up is very involved. Needs a lot of containment, good air managment and supplied air respirators.


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## zerofeel

I have hundreds of homeowners that need to see this post. Thank you!


Andy


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## roofingquotes

I really appreciate this post. Hopefully this will help minimizing molds on my home.


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## pendragon

I know it's well after the fact, but I just joined the forum and this is exactly the kind of information I was hoping to find here. Thank you so much for all your advice.


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## jharris79

" Respirators do not protect you from chemical fumes unless you have the right cartridges"

important information, thank you good sir!


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## johncle6023

Hi

I would just like to say that I am very impressed with your knowledge on the subject of mold! This post is amazing! There is so much misinformation/confusing info out there. I would be so grateful if you could please answer a few questions for me. I have come across this site in my many internet searches in an attempt to learn about the proper way to remove mold from the attic of a house my wife and I are in the process of purchasing. We believe the mold is a result of the bath exhaust being vented directly into the soffits. The mold is light in color and only on a section of the roof sheating and one wall. We will correct the venting issues but am not sure on which process is best to clean the mold.

We have had several companies come to the house and inspect and have received several different suggestions on how to remove/kill the mold. Main differences being the chemicals used. My main concern is something that you mentioned in one of your other posts. I am concerned that some of these chemicals could be worse than the mold itself! We have a 8 month old and while I understand that the attic doesnt share air with the house, I would still like to use as few/safe chemicals as possible.

I would be greatful if you could advise which process is superior/safer in your opinion.

Company A would like to kill the mold with the quaternary ammonium Shockwave. They would then like to clean it with a silicic acid? And finally seal it with a borate product called timbor. I have been told by other companies that the mold is so light and has not spread and that sealing is not necessary though. 

Company B would like to "fog" the area with a product called benefact. I guess thats the kill stage. They would then clean with the hydrogen peroxide based cleaner serum 1000. They do not recommend sealing. 

Company C would like to use shockwave to kill and a bleach solution to lighten and clean. No sealing. 

I would be very greatful to have your opinion as I know you are very knowledgeable on the subject. My main concern is the safety of the air in the house following application. And obviously getting rid of the mold  

The users of shockwave say that it is much more effective but I am unsure about the safety of it. And I am intrigued by company b's use of benefact which appears to be very safe but will this and the serum 1000 be as effective as shockwave?

Would love to know what you would do! Thank you so much in advance for your help!

John


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## SeniorSitizen

QUOTE: Molds require moisture in range of 60% sustained relative humidity or .6 water content.

**********************************************************************
Possibly someone could explain what the *.*6 water content is*. .*6 of what if anything ?


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## Maintenance 6

Fairview said:


> QUOTE: Molds require moisture in range of 60% sustained relative humidity or .6 water content.
> 
> **********************************************************************
> Possibly someone could explain what the *.*6 water content is*. .*6 of what if anything ?


.6 water content means basically that if a particular material holds a certain amount of water, mold will begin to grow when the water level reaches .6 of the maximum. For example, if one square foot of a particular type of wall board will absorb 1 once of water, but no more, then mold will potentially grow on or in that material when the water level reaches .6 of an ounce. That is the simplified version. Point 6 water content can become a useful measurement when comparing materials and when metering. Point 6 water content measured in hardwood is a much different amount of water than .6 in a piece of fiberboard for example.


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## Maintenance 6

johncle6023 said:


> Hi
> 
> I would just like to say that I am very impressed with your knowledge on the subject of mold! This post is amazing! There is so much misinformation/confusing info out there. And some of it from surprising sources. I would be so grateful if you could please answer a few questions for me. I have come across this site in my many internet searches in an attempt to learn about the proper way to remove mold from the attic of a house my wife and I are in the process of purchasing. We believe the mold is a result of the bath exhaust being vented directly into the soffits. The mold is light in color and only on a section of the roof sheating and one wall. We will correct the venting issues but am not sure on which process is best to clean the mold.
> 
> We have had several companies come to the house and inspect and have received several different suggestions on how to remove/kill the mold. Main differences being the chemicals used. My main concern is something that you mentioned in one of your other posts. I am concerned that some of these chemicals could be worse than the mold itself! We have a 8 month old and while I understand that the attic doesnt share air with the house, I would still like to use as few/safe chemicals as possible.
> 
> I would be greatful if you could advise which process is superior/safer in your opinion.
> 
> Company A would like to kill the mold with the quaternary ammonium Shockwave. They would then like to clean it with a silicic acid? And finally seal it with a borate product called timbor. I have been told by other companies that the mold is so light and has not spread and that sealing is not necessary though.
> 
> Company B would like to "fog" the area with a product called benefact. I guess thats the kill stage. They would then clean with the hydrogen peroxide based cleaner serum 1000. They do not recommend sealing.
> 
> Company C would like to use shockwave to kill and a bleach solution to lighten and clean. No sealing.
> 
> I would be very greatful to have your opinion as I know you are very knowledgeable on the subject. My main concern is the safety of the air in the house following application. And obviously getting rid of the mold
> 
> The users of shockwave say that it is much more effective but I am unsure about the safety of it. And I am intrigued by company b's use of benefact which appears to be very safe but will this and the serum 1000 be as effective as shockwave?
> 
> Would love to know what you would do! Thank you so much in advance for your help!
> 
> John


It's hard to judge without seeing the problem, but I will picture it as a lot of white dots and blotches peppered across the surface of the wooden parts of the structure with a tinge of a green tint. Sound right?

First. If you plan to hire a remediator, also hire an independent environmental firm to do air monitoring. Take air samples/spore counts prior to start in the immediate area plus the living space. And then sample in the same places after finish. Include an outside air sample as one of the tests. If you inform the remediator that you plan on doing that, some will either try to talk you out of it or just walk away from the job. Air samples protect you from shoddy work.

In regards to products, Shockwave is OK. It is similar to the Fosters products that we use regularly. As with any chemical, it must be used in concentrations and applied as recommended by the manufacturer. More is not necessarily better. I've never used a silicic acid products to clean. I'm not certain where the advantage lies with it. My process is to clean first, then treat, then seal. I've used Timbor in certain applications and it is a good product. It is not, however, a sealer. After proper cleaning and treatment, some sort sealer should be used but a *fungicidal* sealer isn't really necessary.

As far as company B, I would not walk away from them, I would RUN. Fogging has never proven to be effective as a fungicidal treatment. It is an offshoot of the pest treatment industry. Pest companies that do fogging jumped on this process, but every study I've seen doesn't show much promise. It may work for bugs, but you're trying to kill fungus. If you could see an airflow study on fogging, you would understand my stance. Serum touts their line as a two step system with Serum 2000 as a sealer to be applied after the 1000. Soooo if their going to use only one half of the system, then, well.... what's up with that?

Company C needs to evaluate using bleach as a cleaner. Bleach by itself will certainly kill mold and with a surfactant does an acceptable job, but it is not a spectacular cleaner unless mated with a detergent. 

If you've read my post, then you know that sealing is an important step to permanently lock down any stray stuff and keep it out of the airstream.

No matter who you select, they should establish a negative pressure containment in the space where they are working, exhausted directly to the outside. That will protect you from any noxious fumes or migrating the spore load/mold fragments into the rest of the structure. Attic spaces are certainly the most challenging areas to work in and can be time consuming. Normally the set up time is worse than the actual work. At the conclusion of the work, the air samples taken should reflect a significant drop in spore counts and should at the least match the outdoor counts. Normally they are far lower. That is your assurance that they've done what they said they'd do.

Good Luck!


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## SeniorSitizen

Maintenance 6 said:


> .6 water content means basically that if a particular material holds a certain amount of water, mold will begin to grow when the water level reaches .6 of the maximum. For example, if one square foot of a particular type of wall board will absorb 1 once of water, but no more, then mold will potentially grow on or in that material when the water level reaches .6 of an ounce. That is the simplified version. Point 6 water content can become a useful measurement when comparing materials and when metering. Point 6 water content measured in hardwood is a much different amount of water than .6 in a piece of fiberboard for example.


Thanks for the explanation.

I believe I'll stay with the percentage of moisture by weight method where organic material needs to be less than about 13 percent water. I can check that fairly quickly with scales and a microwave. 

Thanks again, fairview


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## arvinboy

Thanks for the guide, this is very helpful for me. It seems you're a mold expert... or something. Your knowledge about mold is very detail.


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## johncle6023

Maintenance 6 said:


> It's hard to judge without seeing the problem, but I will picture it as a lot of white dots and blotches peppered across the surface of the wooden parts of the structure with a tinge of a green tint. Sound right?
> 
> First. If you plan to hire a remediator, also hire an independent environmental firm to do air monitoring. Take air samples/spore counts prior to start in the immediate area plus the living space. And then sample in the same places after finish. Include an outside air sample as one of the tests. If you inform the remediator that you plan on doing that, some will either try to talk you out of it or just walk away from the job. Air samples protect you from shoddy work.
> 
> In regards to products, Shockwave is OK. It is similar to the Fosters products that we use regularly. As with any chemical, it must be used in concentrations and applied as recommended by the manufacturer. More is not necessarily better. I've never used a silicic acid products to clean. I'm not certain where the advantage lies with it. My process is to clean first, then treat, then seal. I've used Timbor in certain applications and it is a good product. It is not, however, a sealer. After proper cleaning and treatment, some sort sealer should be used but a *fungicidal* sealer isn't really necessary.
> 
> As far as company B, I would not walk away from them, I would RUN. Fogging has never proven to be effective as a fungicidal treatment. It is an offshoot of the pest treatment industry. Pest companies that do fogging jumped on this process, but every study I've seen doesn't show much promise. It may work for bugs, but you're trying to kill fungus. If you could see an airflow study on fogging, you would understand my stance. Serum touts their line as a two step system with Serum 2000 as a sealer to be applied after the 1000. Soooo if their going to use only one half of the system, then, well.... what's up with that?
> 
> Company C needs to evaluate using bleach as a cleaner. Bleach by itself will certainly kill mold and with a surfactant does an acceptable job, but it is not a spectacular cleaner unless mated with a detergent.
> 
> If you've read my post, then you know that sealing is an important step to permanently lock down any stray stuff and keep it out of the airstream.
> 
> No matter who you select, they should establish a negative pressure containment in the space where they are working, exhausted directly to the outside. That will protect you from any noxious fumes or migrating the spore load/mold fragments into the rest of the structure. Attic spaces are certainly the most challenging areas to work in and can be time consuming. Normally the set up time is worse than the actual work. At the conclusion of the work, the air samples taken should reflect a significant drop in spore counts and should at the least match the outdoor counts. Normally they are far lower. That is your assurance that they've done what they said they'd do.
> 
> Good Luck!


Thank you so much for taking the time to reply! I appreciate the advice to avoid the us of "fogging" to apply the biocide. I was wondering if you could explain why I am getting mixed opinions from the remediation people in regards to the use of air scrubbers in the attic space. I have been told that air scrubbers will be used in the attic day of remediation by one company. One company would like to leave them for 3 days. And two have told me that air scrubbers in an attic space is simply a money making tactic used by some companies. They explained that because the attic space is constantly exchanging air already, the use of air scrubbers does not accomplish anything. 

I'm curious where you stand on this!? All companies will provide negative air containment by the way. Thanks again for all your advice!


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## Maintenance 6

If it is not possible to exhaust air to the outside then, air scrubbers (also called traps or negative air machines) must be used. If the air can be vented directly to the outside, then a plain exhaust fan can be used without any filtration. I really don't care what kind of space it is, if it's inside a building, I exhaust my work space air either through a HEPA filtered trap or directly to the outside. I see no reason to run negative air for three days if the containment is erected properly and the remediation is done correctly, UNLESS he has reason to suspect there may be a spore load outside of the remediation area that will be impossible to clean. That could be exposed fiberglass insulation for example that might have mold debris entrained in it, but was not part of the original problem. Then a flush with some forced air might be good. I would avoid anyone who wanted to do the job without any sort of negative pressure environment in his containment, trapped or not.


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## Maintenance 6

You have to wonder what good a containment is, if there is no fan to keep it negatively pressurized. For fun, ask the companies to see documentation that their trap has been tested. We checked a bunch of traps already and found about 90% had problems of some sort. Some that had never had the filters changed (years old). Some that bypassed up to 5% of the air around the filter because it was poorly installed. Some that the users had unhooked the magnahelic gauges that monitor the filter loading. And even some that had no HEPA filters in them. Just a pre-filter taped across the intake. Companies like these are in the "Mold for Gold" business and DO NOT have your interest at heart.


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## -aaa-

Maintenance 6 said:


> You have to wonder what good a containment is, if there is no fan to keep it negatively pressurized. For fun, ask the companies to see documentation that their trap has been tested. We checked a bunch of traps already and found about 90% had problems of some sort. Some that had never had the filters changed (years old). Some that bypassed up to 5% of the air around the filter because it was poorly installed. Some that the users had unhooked the magnahelic gauges that monitor the filter loading. And even some that had no HEPA filters in them. Just a pre-filter taped across the intake. Companies like these are in the "Mold for Gold" business and DO NOT have your interest at heart.


Wow! really good info. Thanks man!


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## Brainbucket

I was hit with the August floods in southern Louisiana. I got 5 inches in the house. I ripped out 4 feet of drywall up from the floor and removed the wet insulation. There was mold everywhere bout 2 feet up from the floor. The fella that was helping me said that's old mold, not from this flood. He was right as it was from Hurricane Gustaf that put a tree through my roof that made a 20 foot hole. It was like that for 4 months because insurance company were dragging their feet. Anyway a fella convinced me to 'fog' it. He did. When I ripped the wall paper out, I seen lines here and there and I though were from the wallpaper. It was mold. After he fogged the house and attic, all the mold was gone and it hasn't returned. The walls were naked 4 feet from the floor so I figure that helped. I sure hope that the fog worked for me. I still have some stud still naked as the insurance company is dragging their feet and not wanting to pay but the mold in the worst spots is still mold free. So I say it worked in my case. What do you think or did I throw money away? Sure hope not.


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