Toxic Mold Prevention

Whenever Anchorage Construction performs water-damage-repair work, we apply an EPA Registered Fungicide Concentrate called Oxy-Mold MX-500™ to prevent future mold growth from the flooding. The following articles by mold-remediation experts describe the methods that we use for mold prevention.

How to Get Rid of Mold in a Crawl Space

By: Jim Dobbins, Sr. Mold Remediation Specialist

CONTAIN- the mold from spreading into uncontaminated areas;

KILL- the mold;

REMOVE- the dead mold and materials used for remediation; and

PROTECT- the cleaned out area against future mold infestations.

Mold in the crawl space is one of the top three mold problems common to a home, affecting 1 in 3 crawl spaces in the United States. Left untreated the health effects can be disastrous to you and your family.

If you have mold in your crawl space or suspect it, it is a good idea to do a mold test inside your home for mold. The mold from your crawl space may have infected your home from small drafts and HVAC systems which blow spores throughout your home. 

The only way to be sure is to conduct a laboratory mold test.

 1.) First fix the problem that caused the mold to form.

 Mold in the crawl space is generally caused by increased humidity and moisture. The source of the moisture can be from the ground in the crawl space, improperly or to few installed crawl space vents, improperly or no installed plastic sheathing or visqueen, a water leak allowing water to stand in the crawl space from new construction, a leaky water pipe, or any other source of moisture.  A dryer may have been vented improperly into the crawl space or crawl space vents may either be closed or there may be to few vents to support the moisture in the crawl space.

ALL crawl spaces must be vented properly, even during the winter. A common misnomer is that the crawl space vents should be shut during the winter season. This is not true. As moisture builds in the space, mold will form on the ground, floor joists, plywood, or any organic material which serves as food for mold. This can lead to mold spores migrating into the home and can potentially, if left untreated cause a total loss of a home from severe mold infestation.

 2.) Get the area as dry as possible before starting your remediation project or it will not be a successful remediation. 

You must either pump out standing water (if you can see it), and then start the process of drying out the space by using at least two fans. One to circulate the air inside the area (more fans may be required for larger areas, and another fan to pump inside air outside of the crawl space. Some Remediators will bring in a HEPA filters, or positive air machines during this process to prevent mold spores from moving inside the home and outside of the crawl space. Some crawl spaces will require the use of a dehumidifier to remove excess water from the space.

You want the space as dry as possible (below 30% relative humidity) before starting the work, so that the a fungicide registered with EPA for this application  can penetrate deeply into the treatment surfaces and kill the roots of the mold effectively.

 - Some crawl spaces may need to have new 6 mil plastic placed down over the dirt after the remediation process is completed.

 - Some crawl spaces may have to be concreted in to prevent water from entering the crawl space. (This is common in wet, swampy areas of the country)

 - When HVAC systems and ducting are run under a crawl space, it is possible that the mold may have penetrated into the HVAC system and therefore blown around the entire home. The home and HVAC should be thoroughly tested for mold. If there is elevated levels of mold present in the home, it will be necessary to remediate the home as well.

 3.) All areas of the crawl space must be treated with a fungicide to kill the mold

 Even if the mold is just in one area of the floor joists, you must treat the entire dirt, visqueen (plastic), all floor joists, and foundation with a minimum of two full treatments, letting it dry in between each treatment.

 There are two ways to treat the crawl space. Fogging, and pump spraying.

 - Fogging is a method of dispersing atomized product into the crawl space area without having to go under and pump spray everything which is a very uncomfortable and tedious task with Personal Protective Equipment (PPE) and respirators on.

 - Break the crawl space area into quadrants of about 15’ x 15’ areas. You will move the fogger to each quadrant, fogging generally 45 minutes per quadrant.

 - If you are fogging it is more convenient to use a cheap 1 hour timer to turn the unit off after it has finished.

 - Put the fogger in the middle of the crawl space (It may be different for different crawl space layouts) and turn the unit on facing the one of the corner quadrants such as the example above.

 - Simply fill the 1 ½ gallon tank on the unit with EPA approved fungicide, turn on the fogger, set the timer for 45 minutes and leave the area.  If you are going to be in the space while the fogger is running, you must wear protective eyewear and an N95 rated respirator. Repeat the process for each quadrant.

- No one should be in or near the crawl space while the fogger is running. Do not re-enter the space until the fog has settled for an hour.

 - Pump spraying is also a way to accomplish this task, keeping in mind that you must do at least two treatments with soaking all floor joists, plywood, foundation, and dirt/plastic, letting it dry in between treatments. You should wear an P100 rated respirator while pump spraying in confined areas.

4.) Mold remediators would HEPA VAC any visible mold areas

A HEPA vacuum can be used to vacuum away dead mold spores on your crawlspace. This is not required, but is a good practice. Do not use anything but a HEPA rated vacuum cleaner or you are just blowing mold spores around your crawl space or home.

5.) Mold killers do not remove stains from mold on your floor joist and plywood.

It is possible to kill mold without the mold changing much in color. Molds have VERY strong pigments, and the roots of the mold actually grow into the wood. This causes in some cases permanent staining. You may try using bleach to get the stain out prior to using a fungicide. This bleaches the mold but does not effectively kill it. If you are concerned with the stains you need to decide what type of fungicidal coating to use (white or clear) to either cover the satins or seal them in.

The other option is to "brush" or sand the stains out. This is a tedious task that remediators get huge sums of money to do, but it does remove the stains. After the sanding, you can use a fungicidal coating to seal the areas in.

6.) Mold sealants are generally a good idea after the mold is dead to get long term fungicidal activity underneath the crawl space.

After the mold is dead (from 2 treatments) use the fungicidal sealant Anti-Growth™ to seal in the dead mold areas. This will provide long term fungicidal activity and deter growth for 2-5 years depending on the conditions in your crawlspace.

If all of the moisture problems are solved and you have used a mold sealant, your mold problems should be a thing of the past.

Mold Remediation of Drywall

By: Matthew Yurina, Sr. Mold Remediation Specialist

CONTAIN- the mold from spreading into uncontaminated areas;

KILL- the mold;

REMOVE- the dead mold and materials used for remediation; and

PROTECT- the cleaned out area against future mold infestations. 

Drywall mold that has high mold contamination are a major source of allergens and possibly mycotoxins in the home. Drywall mold or black spots are generally due to water damage, high humidity, or a leak behind drywall. Allowed to go undetected or ignored can cause severe health problems and damage to a home or office.

Physical mold growth on drywall needs to be removed carefully, bagged and disposed of. Standard practice is to cut the moldy material away up to three feet from where the visible growth is. There’s no safe and truly effective way to both kill and clean up mold on surfaces like drywall.

The first step in any mold remediation effort is to acquire the proper protective equipment: P100 respirator (to filter mold spores so you don’t breathe them in), gloves, goggles and disposable clothes that cover all of the body. If disposable clothes are not available, then you’ll want to ware clothes that you can wash immediately after the project in the Oxy Mold Cleaner product. In any enclosed area where you’ll be spraying or fogging, you’ll need a P100 respirator that will also protect against the chemical fumes of the fungicide you’ll be applying.

The second step would be to pinpoint the source of the mold growth and contain it as close to that source as possible. In may be necessary to erect walls of plastic sheeting to keep mold spores from spreading to uncontaminated areas.

The third step will be to use any method available to you to reduce humidity in the moldy area and dry out all infected surfaces. OXY-MOLD MX-500, along with all fungicides, will penetrate far deeper into dry surfaces than wet ones. You may need to purchase a dehumidifier to get the humidity below 50%. Air moving devices or fans may be appropriate if you take into account that you could be spreading mold spores around. In a heavy mold infestation the idea is to limit the amount of spores that get spread around, thus lowering the chances of contaminating new areas.

Effectively killing mold in drywall is virtually impossible. The difficulty isn’t necessarily that the surface mold can’t be killed, but that drywall is too porous to effectively kill the mold that has grown into and through the drywall substrate, thereby presenting a hazard. The safest measure will always be to remove the infected drywall, sometimes even up to three feet in all directions from the actual visible growth.

The quickest, easiest and inevitably the cheapest way to fix the problem will be to remove the drywall (carefully with a drywall cutter or similar blade that will keep the spread of spores to a minimum), and bag it up securely in plastic bags, or 6 mil polyethylene if there’s a great quantity. Once removed from the house the bags can be taken to a landfill.

In most cases there is more mold growth on the inner side of the drywall that cannot be seen, and it could even have contaminated insulation ceiling tiles and studs. It depends upon the source of leak or moisture problem that caused the mold, but usually there’s need for performing Mold Tests in order to help understand the full extent of the mold contamination in a home or office. While condensation due to humidity or improper ventilation may not have caused too extensive of mold growth all the way behind the walls, actual water or sewage leaks could significantly lessen the time it takes for the mold to spread right through the drywall and into other surfaces.

Unless the moisture intrusion and the mold problem have been ongoing and building up for a long period of time, the wood itself should be salvable. Even on the studs you’ll want to remove as much of the mold growth as you can. It may also be necessary to apply the Impact once before physical removal of the mold in order to lessen the spread of spores. If you have to cut more than a fifth of and inch into the studs to remove the growth, the studs themselves will not be salvable, as this will threaten the house’s structure. These studs would have to be removed and replaced.

Once all removable mold growth is safely away from the area, it’s time to apply the MX-500 product twice to the entire infected area, letting the area dry for twenty-four hours in between applications. In areas of small or limited mold infestation it should be satisfactory to apply the Impact with a spray bottle or garden pump sprayer, but in any heavy infestation (heavy = you can smell the mold), then Fogger will be the only appropriate method.

A cold fogger will atomize the biocide, turning it into droplets of micron size so that it can penetrate to the deepest roots of the mold and kill surface and airborne mold and mold spores.

When airborne mold spores are involved another step will most likely be needed to actually clean the dead mold spores from the air. You’ll want to look into buying or renting a HEPA grade air mover that can filter the old, contaminated air and remove it from the area while bringing in pure, uncontaminated air. This will be necessary because even dead mold spores can be a health risk.

Once the project is completed it is in your interest to perform post testing (clearance testing). This is the only way to be sure it’s safe to reinstall drywall, insulation, etc. The worst thing you can do is rebuild over an unresolved mold problem. You’ll also want to make sure that the original moisture problem is fixed. Once these tests prove clear, you can re-insulate, rebuild, and repaint. The final application of a fungicidal sealant like Anti-Growth can prevent mold growth for up to five years.

These instructions are general in nature, and there are always situations that can make certain parts of the remediation more difficult. Feel free to contact us by phone Monday through Friday, 9:00 to 5:00 Eastern Time if you have any questions that our web site doesn’t answer. Our biggest concern is that you’re performing the mold remediation properly.

After the mold remediation is completed, mold test (clearance testing) all of the remediated surfaces plus the air of each room in the basement, and the outward air flow from each heating/cooling duct register to find out if those areas are now mold safe prior to rebuilding the cleaned out areas with new building materials.

Remediating Mold in HVAC / A/C System

By: Thomas Jenkins, Sr. Mold Remediation Specialist

CONTAIN- the mold from spreading into uncontaminated areas;

KILL- the mold;

REMOVE- the dead mold and materials used for remediation; and

PROTECT- the cleaned out area against future mold infestations.

Mold in HVAC and heating / air condition systems is a top cause of mold infestation in a home. Allowed to go ignored can cause up to a total loss of a home or office, and creates a health hazard for families and employees.

Air Conditioning Heating Equipment and Duct Mold Problems:

When humid air passes over chilled cooling coils, water condenses and drips through the coils into a collection pan, from which it continuously drains. Problems with these systems may occur when this water collects and becomes stagnant when it becomes blocked, either on the coils or in the drip pan. The pan will grow mold that can infect your home with dangerous mold spores very quickly. Problems also exist when the HVAC ducting contains microscopic mold spores that stay continually present and blow contaminants around the home or office often caused by mold in other parts of your home.

Mold and mold spores may also be introduced to your home via a mold problem in another location in your home. For instance there may be mold in your attic, crawl space, basement, etc that has been allowed to go untreated that can release allergenic and toxic mold spores into your HVAC system. Once these spores have been introduced to your HVAC they can be carried through the ducting to your entire home. To learn more about mold treatment in other areas of the home.  Although professional duct cleaning is recommended, it does not always get these microscopic mold spores out of the duct system. Therefore other procedures for mold remediation may be necessary.

 1.) Locate and fix all sources of mold-causing water intrusion such as HVAC drain line backup, water damage/flooding, roof leaks, recurring flooding, plumbing leaks, poor drainage, etc.  These problems cause mold spores to be introduced to your HVAC system and cause the spores to be blown around your entire home. To learn more about mold treatment in other areas of the home.

The HVAC system should be either shut down or vents closed off to prevent further contamination the rest of the home or building until a treatment protocol can be administered. HEPA filtration of the home may also be required during this process.

 2.) If your air conditioner / HVAC system is infected with mold, then you should consider fogging your duct system and air handler with a ULV mold fogging device and a fungicide registered with EPA for this application while the system is running on fan mode to deliver the fungicide to internal surfaces. Certain precautions must be taken when trying to accomplish this task, including proper personal protective equipment and vacating the entire building. 

• While spraying or fogging a fungicide registered with EPA for this application inside the heating/cooling ducts and equipment, absolutely no one [except the protected applicator] should be in the home or building during the spraying or fogging application. The person doing the spraying or fogging application needs to wear proper personal protective gear like an P100 rated respirator and goggles when entering the space during and after application.

• Do not run the HVAC system until the rest of the home has been effectively remediated of mold and the building has passed mold clearance tests.

  ° While working inside the mold containment area, always wear effective protective gear such as protective biohazard suit. These are fairly inexpensive, or paint coveralls and booties or a long sleeve shirt and pants; gloves; and  a one piece, full face P100 rated breathing respirator mask using an organic vapor cartridge filtration available from home improvement stores. You also need such personal protective gear when you spray fungicides. 

• Tyvek protective biohazard suit or painter's coveralls and booties, or long sleeve shirt and pants (not required).

• Gloves: either disposable latex or good work gloves. Avoid touching mold or moldy items with your bare hands," recommends the U.S. Environmental Protection Agency. 

• Avoid breathing in mold, mold spores, or fungicide vapor. Wear a P100 rated one piece, full face breathing respirator mask using an organic vapor cartridge filtration, available from your local Home Depot or Lowes. Please note that the Occupational Safety and Health Administration (OSHA) requires that respirators fit properly (fit testing) when used in an occupational setting; consult OSHA for more information (800-321-OSHA or osha.gov," advises the U.S. Environmental Protection Agency.

• Wear goggles. Wear eye goggles with no holes if you are not wearing the P100 one piece, full face breathing respirator.  "Goggles that do not have ventilation holes are recommended.  Avoid getting mold or mold spores in your eyes," advises the U.S. Environmental Protection Agency.

• Pump spray or fog the areas that have visible mold growth.

3.) MAKE SURE EVERYONE INCLUDING CHILDREN, PEOPLE, PETS, FISH, BIRDS, ETC. IS OUT OF THE BUILDING BEFORE FOGGING. Once you are sure the area is clear, you may fog using a ULV fogging device and an EPA approved fungicide.

• Take out the air filter out of the HVAC system

• Wear P100 rated respirator and safety gloves and goggles. Take off the grate on the return air side (the side that pulls air into the HVAC system) and turn of the fogger with EPA approved product in it. Let it run from 20-30 minutes. The fogger may require a timer purchased from you local hardware store so that it can shut off without burning the motor up or you will have to go back inside and shut it down before the liquid runs dry.

• Let the area sit for 3-4 hours before returning with your respirator on. Open all windows and ventilate for several hours. Once the area is dry and free of odor, people may return to the fogged area.

• Perform step 3 twice.

• Once fogging is complete make sure to wipe down or wash any surfaces or products with water that come into contact with food. Discard any exposed foods. 

4.) After the mold remediation is completed, mold test (clearance testing) the HVAC system to find out if those areas are now mold free.

5.) Use high end 3M Filtrete 1000+ air filters in your system and replace monthly (not quarterly) to help trap any remaining mold spores

Mold Remediation from Flooding

By: Thomas Jenkins, Sr. Mold Remediation Specialist

REMOVE - the dead mold ; and

PROTECT- the cleaned out area against future mold infestations.

Flooding either by rain, hurricane, or leaking pipes is a top cause of mold infestation in a home. Allowed to go ignored can cause up to a total loss of a home or office, and creates a health hazard for families and employees.

1.) Locate and fix all sources of mold-causing water intrusion such as water damage/flooding, roof leaks, recurring flooding, plumbing leaks, poor drainage, etc.  Get the home or office as dry as possible using fans and dehumidifiers, water pumps to dry it out. If the home or building is multi-story building then the area leading up to the second floor or other rooms not contaminated should be closed off and contained with plastic sheathing so that mold spores to not migrate to areas that do not contain mold. The HVAC system should be either shut down or vents closed off to prevent further contamination the rest of the home or building.

 °   Use a fiber optics inspection device, a hidden moisture meter, and internal wall and ceiling cavity mold testing to search for hidden mold growth or water if you can not see it or feel that it may be present.

 °   Mold can start growing in as little as 48 hours after water damage! Remove any drywall and insulation that has gotten wet up to 6 inches from the waterline as soon as possible. Bag all material in 6ml plastic and discard it safely outside the home or office.

 °   Allow the area to be 100% dry. Be patient as flood damage can take weeks or more to completely dry out. Area may still be wet that you can not see behind. Run HEPA filters and adequate dehumidifiers to aid in the process.

 °   Being 100% dry is VERY important to support the next step which is the use of an EPA registered biocide to kill the roots of the mold. If it is not dry then the biocide can not penetrate to kill the roots of the mold and the mold may return.

°  Before beginning to work in the mold-afflicted areas, contain the moldy work area (and thus contain the toxic mold spores that will be released into the air by opening up mold-contaminated areas) by using wall-to-wall, floor-to-ceiling plastic sheeting as containment walls. Use 6 mill thick, clear plastic sheeting that you can buy at a hardware store or home improvement center.

° After the installation of air tight mold containment walls, dry the work area especially if still wet from flooding or a now fixed water leak with one or more large dehumidifiers or an industrial size dehumidifier. Improper fan drying can spread mold spores to cross contaminate an entire building and its heating/cooling system.  Inside the mold containment area, use a large fan in the window to exhaust air directly outside on a continuous basis to expel airborne mold spores and remediation-caused dust or an industrial HEPA filter to filter out mold, with a flexible hose directly venting the exhaust air flow to the outdoors. You need to exhaust more air to the outside than is entering the containment area to create negative air pressure.

° While working inside the mold containment area, always wear effective protective gear such as protective biohazard suit. These are fairly inexpensive, or paint coveralls and booties or a long sleeve shirt and pants; gloves; and  a one piece, full face breathing respirator mask using an organic vapor cartridge filtration available from home improvement stores. You also need such personal protective gear when you spray EPA registered mold killing fungicide. 

• Tyvek protective biohazard suit or painter's coveralls and booties, or long sleeve shirt and pants. 

• Gloves: either disposable latex or good work gloves. Avoid touching mold or moldy items with your bare hands," recommends the U.S. Environmental Protection Agency. 

• Avoid breathing in mold or mold spores. Wear a P100 brand one piece, full face breathing respirator mask using an organic vapor cartridge filtration, available from your local Home Depot or Lowes. Please note that the Occupational Safety and Health Administration (OSHA) requires that respirators fit properly (fit testing) when used in an occupational setting; consult OSHA for more information (800-321-OSHA or osha.gov," advises the U.S. Environmental Protection Agency.

• Wear goggles. Wear eye goggles with no holes if you are not wearing the N95 one piece, full face breathing respirator.  "Goggles that do not have ventilation holes are recommended.  Avoid getting mold or mold spores in your eyes," advises the U.S. Environmental Protection Agency.

• Pump spray or fog the areas that have visible mold growth with an EPA approved product two times letting it naturally dry in-between sprayings.

IMPORTANT OZONE WARNING: Do not use an Ozone Air Purifier/Ozone Generator to kill mold. Ozone is ineffective in killing mold. Ozone can only kill what it comes into contact with. Ozone cannot get at, and thus cannot kill, mold growing INSIDE drywall, wall, carpeting, upholstered furniture, wall cavities, ceiling cavities, and floor cavities. Besides being ineffective at killing hidden mold [the worst type], a high ozone treatment can easily damage all rubber and plastic parts it comes into contact with such as rubber and plastic components of appliances, electronics of all types, exposed electric lines and extension courts, and hvac controls. Ozone is also unhealthy to humans according to the U.S. Environmental Protection Agency, which specifically discourages the use of ozone for mold remediation. For more information on the ineffectiveness of Ozone and the Ozone Air Purifier to kill mold and other indoor air contaminant, read the highly-informative U.S. Federal Appeals court decision: Federal Trade Commission and the Court of Appeals. 

2.) If you have to, you can use bleach to keep the mold under control until you can get a fungicide registered with EPA for this application to kill it permanently.  Bleach will not kill the roots of the mold. It will simply keep it under control until you can get a biocide on the area. Bleach is not an effective or lasting killer of toxic mold growth and mold spores on and inside porous, cellulose building materials such as wood timbers, drywall, plasterboard, particleboard, plywood, plywood substitutes, ceiling tiles, and carpeting/padding. Bleach also destroys the wood that hold your home together.

° Unfortunately FEMA has recommended to flood victims that bleach should be used to kill the mold, this will appear like is has worked, and the individual will replace the insulation and drywall and close it back up only to find that the mold will be growing through the very drywall they just replaced in 3-6 months. The job will have to be done again using proper biocide and techniques for mold removal.  Do you really want to go through this again?

 3.) Once the area is completely dry, then either fog with a mold fogging device or pump spray the entire area with an a fungicide registered with EPA for this application. Be sure to soak all studs, flooring, affected drywall that is salvageable. This will have to be done two times letting the treatment dry in between. Generally this takes 24-48 hours to completely dry.

Fogging can be accomplished by breaking your rooms into 15' x 15' areas.

The fogging device is filled with 1 1/2 gallons of EPA registered mold killer, then allowed to run for 30-45 minutes per 15' x 15' area. Use a cheap timer to shut the machine off after the 45 minutes has passed. Always wear proper protective equipment when fogging.

 4.) If your air conditioner / HVAC system is infected with mold, then you should consider fogging your duct system and air handler with a ULV mold fogging device and an a fungicide registered with EPA for this application while the system is running on fan ventilation to deliver the fungicide to internal surfaces. Certain precautions must be taken when trying to accomplish this task, including proper personal protective equipment and vacating the building.  Air conditioning-heating equipment and duct mold problems. When humid air passes over chilled cooling coils, water condenses and drips through the coils into a collection pan, from which it continuously drains. Problems with these systems may occur when this water collects and becomes stagnant when it becomes blocked, either on the coils or in the drip pan. The pan will grow mold that can infect your home with dangerous mold spores very quickly. Problems also exist when the HVAC ducting contains microscopic mold spores that stay continually present and blow contaminants around the home or office.

• While spraying or fogging a mold fungicide and subsequently a fungicide registered with EPA for this application inside the heating/cooling ducts and equipment, no one [except the protected applicator] should be in the home or building during the spraying or fogging application. The person doing the spraying or fogging application needs to wear proper personal protective gear like an P100 rated respirator and goggles when entering the space.

• When doing mold remediation of a house or building, the heating/cooling mold problems should be fixed first, and then you can seal tightly with plastic sheeting all inward and outward duct registers. Do not run the system until the rest of the home has been effectively remediated of mold and the building has passed mold clearance tests.

 5.) Do not paint over mold problems. Mold uses paint as food. Don’t expect to kill mold successfully by using paint containing a mildicide (it is too weak to kill existing toxic mold infestation) or with a paint primer sold to hide water damage stains. Do not rely on Kilz to kill mold or anything, it does not kill mold, it does not contain a fungicide, and the product is NOT an EPA-registered fungicide. Kilz is an excellent product to hide or camouflage defects like water damage stains prior to painting over problem areas. You can use a mold inhibiting paint / clear coat like Fosters 40-50 for this purpose. 

 6.) After the mold killer has dried, then spray a liquid fungicidal coating such as Anti-Growth™ mold sealant concentrate which will provide a barrier and will inhibit mold growth and moisture for 2 to 5 years or more.

 7.) After the mold remediation is completed, mold test (clearance testing) all of the remediated surfaces plus the air of each room in the basement, and the outward air flow from each heating/cooling duct register to find out if those areas are now mold safe prior to rebuilding the cleaned out areas with new building materials.