Western North Carolina Green Building Council

What you need to know about mold and how to stop it!

Topics Include: Basic Mold background, Info about Mold Clean Up, Mold Abatement and Protection after Mold Abatement.

What is Mold?   

Mold are fungi that grow in complex colonies called hyphae: these are the black mold, mildew, and basement mold spots we find in our homes and other built environments.  These colonies spread and reproduce through tiny spores that can travel long distances in the air and on host surfaces.  Mold is everywhere, and serves an essential purpose in the natural environment, breaking down dead matter such as dead leaves and plants.  There is mold in the air and on surfaces all around us, both indoors and out.  The presence of mold spores is basically unavoidable, including indoors.  Preventing the growth of mold colonies, however, is certainly possible indoors by eliminating the conditions mold requires to proliferate and by preparing surfaces that are inhospitable to mold growth.  

Why should I worry about mold abatement?

Molds a are a significant health risk for many people.  Molds can cause symptoms ranging from simple irritation and odor to allergic reactions, and in some cases very serious long-term health damage, debility, and even death.  Sneezing and congestion, red eyes and skin, and other reactions can set in immediately upon contact to mold, or may be delayed in their onset.  Mold can also cause asthma attacks in sensitive people.
       Additionally, certain specific types of mold contain highly toxic substances that can cause more serious effects.  There are frequent reports of immune system and neurological damage due to chronic or serious mold exposure.  Information in the links below provide further reading about the potential risks to humans and homes. Many people have become ill from mold and many lawsuits have been lost at great expense to the owner.

How Does Mold Grow (and how to slow it down)

All mold requires to grow is a mold spore, moisture, a nutrient source, and appropriate temperatures.  Because sunlight and airflow tend to evaporate moisture and dry out surfaces and materials, we tend to find mold in dark, stagnant environments, particularly where there is a large supply of moisture. A basic premise in stopping the spread of mold is the fact that active mold colonies, left to their own devices, can release massive numbers of mold spores and dramatically increase the chances of further mold growth and damage to human heath.  So, destroying existing colonies and keeping major sources of mold from entering our homes is a key part of mold remediation.   For example, lumber is often left outside in the rain before a house is built. Then it is put up with little thought for the mold growing in it. This can create trouble from black mold in wall cavities even though no water directly damages it, and where normally mold growth wouldn't be a problem.

However thoroughly we eliminate the sources of mold spores, there will always be countless mold spores in the ambient environment that are perfectly happy at the temperatures appropriate for humans to live.  And, in our homes and buildings, microscopic dust and other strata in and on our surfaces provide ample nutrients for mold to grow. Even with good air flow and humidity control in living spaces, significant amounts of basement mold can accumulate in walls, under carpets and cabinets, and in other sealed cavities out of sight. Spores and musty odors then emanate throughout the house. Black mold can even accumulate in ceilings as a result of leaky pipes and fixtures.   So, the main thing you can do to prevent mold growth is controlling humidity and water sources.

    However, occasional leaks in pipes, and occasional damage do to flooding or other unforseen problems happen regularly even given people's best precautions.  21% of all insurance claims in 2003 were related to water damage and freezing pipes, with an average claim cost of over $4,900.  Over 37% of homeowners report losses due to water damage.  So, additional readiness measures are called for.   Natural surface treatments that eliminate black mold stains and create environments inhospitable to the formation and growth of mold stains, such as basement mold stains and black mold stains, are great front-line prevention due to everyday conditions, and also can be a big help in avoiding problems as a last line of defense against leaks and water infiltration.  Applying these treatments to all your at risk surfaces, both in sealed cavities and in living areas, can help remedy existing black mold stains and also stop new black mold stains from forming.

Mold Abatement: A Four Step Clean Up and Preparation

Step 1: Protect yourself first

Small scale mold problems (the EPA defines this as under 10 sq. ft. of mold growth) can be tackled using care and good practices by individuals whose health isn't at risk due to mold exposure.  Individuals experiencing serious mold reactions and individuals with immune or respiratory concerns should consider looking for outside help with mold abatement.  For small-scale cleanup, basic personal protective equipment to protect lungs, eyes, and skin include an OSHA approved N-95 respirator (not to expensive and available at a local hardware store), goggles that seal around the eyes, and gloves.  Even for small-scale cleanup, it is wise to protect surrounding areas, including air vents, furniture and living areas, from high levels of mold release due to disturbing mold colonies during cleanup.

    Larger scale mold abatement requires additional protective equipment and site preparation.  Sealing off the air in the affected area from surrounding areas, using specialized air filters and particulate vacuums for cleaning equipment and clothing, special protective clothing and respiratory equipment, and more may be necessary to prevent spreading contaminated materials and air throughout a wide area and in order to protect the health of those undertaking the cleanup.  Experienced specialists are generally necessary in cases of major mold issues, for the safety of the cleanup crew and also for the likelihood of success in the operation.  In the cases of water damage involving sewage and especially when there is the chance of structural damage to a building, appropriate expertise is a called for.    

Step 2:  Remove Mold Colonies and Damaged Material
: Dead mold is just as toxic as living mold.

    During the mold abatement process you will find cleaning solid surfaces is less difficult than porous materials. Carpets and insulation are notoriously difficult to clean up and frequently need to be discarded.  Solid surfaces can be scrubbed with a safe, tough cleaner appropriate for fighting mold stains (such as Earthpaint's Earth Clean ) until all visible mold has been removed.  Mold deposits that have made their way into cushions, carpets, insulation, etc. should be removed from the building in sealed bags, to prevent spreading the mold further throughout the area.
    Toxic cleaners should be avoided during mold abatement or when attempting to remove mold.  The EPA recommends against using bleach, which can be harmful to humans and the environment, because the potential dangers greatly outweigh the benefits.  Other toxic fungicides are also available to attempt to fight mold.  However, introducing one toxin into the environment in order to try to fight another is an exercise in futility.  What's more, dead mold is just as toxic to health as living mold.  Toxic products are not needed when cleaning and removing black mold and basement mold stains naturally. Earth Clean and Lime Prime can be indispensable here.

Step 3: Eliminating Sources of Moisture and Reducing Surface Humidity

    Some mold problems occur due to identifiable point source or episodic moisture exposure, such as floods or leaky pipes.  It is essential to eliminate these sources of water, since water is the key ingredient in the outbreak of a mold problem.  When dealing with recurring (not due to a natural disaster!) infiltration of water through a foundation, or from outdoors, trapping moisture can be a big problem, especially since it creates black mold breeding grounds.  If you have just had a leak or a flood expose your basement or living space to a black mold or basement mold threat, do not delay in drying out the area, removing as much water as quickly as possible.  Moisture lingering on a surface for several days can be sufficient impetus for a mold colony to begin to form.

       Waterproofing alone is not usually successful mold abatement in a basement. Without digging in drainage pipes, directing water away from the house and waterproofing the outside of the foundation, black mold and mildew can still fester. This is a reason that air-permeable surface treatments like Earthpaint's Lime Prime are superior to sealants that trap damaging mold into hidden areas.  These trapped colonies can damage structural materials and insulation, and usually find a way to release mold spores out into the living space. If water is flowing it needs to be stopped but if the area is just moist because it's below grade then a breathable coating like Lime Prime is perfect after your mold abatement is completed.

    There are many specific ideas for reducing indoor condensation and humidity due to human causes to be found in the links section.  Key universal precautions include adequately venting bathrooms, appliances such as dryers, stovetops, and other moisture sources and insulating cold surfaces on walls and pipes to prevent condensation.

       Natural high humidity is present in many regions, and especially in cool basements, and can often be serious enough to promote mold growth on its own without other spills and leaks.  The maximum recommended range for interior humidity various by source from 40 to over 60 percent humidity.  Relative humidity below 50 percent is considered safe by most estimates.  Many people install significant dehumidification systems in their basements and homes, which can be very effective tools.  One must consider the costs, high energy requirements, and environmental consequences of employing electric dehumidification.  

Mold growth generally occurs on surfaces and in substrates where condensation (even of microscopic water particles) occurs.  Air movement across a surface can wick away moisture and dry out a surface even when ambient humidity is still.  This means that fan and ventilation systems can be effective alternatives to dehumidifiers in some cases.  Crawl spaces and basement wall cavities with no ventilation are prime examples where black mold and other molds can take hold because moisture that infiltrates into the area is never expelled.

    As in most aspects of healthy homes, but especially in mold abatement, it is ideal to incorporate passive air flow through the home into the initial design (using cupolas or any of a range of other design elements that create an air current through the home and across the wall and foundation surfaces-see our links section for an ever expanding collection of design resources).  Some homes do not include such design elements, especially in newer homes built with tighter air-flow control in the building envelope.  Tighter buildings especially that promote energy efficiency can sometimes seal in moisture problems and stagnant air resulting in worse mold issues. When you do your mold abatement keep this in mind and make whatever structural changes seem appropriate.

    In some situations, mechanical ventilation can promote air flow, a beneficial vector of suction across foundation walls, and better air quality.  Again, energy consumption is a big issue.  An interesting low energy alternative that is continually decreasing in price is solar powered fans, running on direct current and without a battery.  Some home designs include a solar fan that constantly ventilates the cavity around the foundation of the home, drying out the basement walls whenever the sun shines, effectively bringing light to the darkness and reducing basment mold issues.  Similar vent fans also exist for attics and so forth.  Again, check the links for an expanding collection of alternative energy source ideas, or let us know about your bright ideas here.

    In short, higher ambient humidity can be tolerated with good air flow to dry out surfaces.  Higher temperature air also evaporates moisture, and again, energy costs are an important factor to weigh in making decisions.

Step 4: Protect your surfaces during Mold Abatement:

    Paint all mold and mildew stains with Lime Prime. In all at risk areas, including bathrooms, basements, around foundations, etc. use Lime Prime on the surfaces inside and around your wall, floor and ceiling and wall cavities to create a durable, natural surface that doesn't support growth of mold and mildew stains. Earthpaint's Clear Skies paint can be applied over Lime Prime, tintable in any color to fit your design. Lime Prime can also be left white on ceilings.  For natural wood surfaces, Earthpaint also sells a variety of natural and non-toxic wood finishes appropriate for any application, both indoor and outdoor.

    There are other paints available that contain fungicides and mildewcides (aka. Pesticides).  However, the hazards to health that occur when using such products, even including standard house paints, rival the dangers of mold itself.   Chemical mildewcides often stop working after a year or two. Most people spend 80-90% of their time indoors.  We have selfishly bequeathed toxic buildings, and a toxic world upon our children all in the guise of "convenience".  Toxic biocides are a temporary solution to a permanent problem. Nature gave us Black Mold and it also gave us the solutions to deal with it. We have to be creative not destructive in our approach to mold abatement.

    Building Green is not about poisoning the earth. It is about being healthy and sustainable, improving the quality of life; working smarter not more frantically out of fear. A good life is available to us all, full of energy and vitality and we do not need to build any more poison into our lives. The common thinking of "I have to use this poisonous product because it's the only thing that works." has led us down a path of destruction.

    Not just the application of biocidal paints is toxic, but also the processing to make toxic chemical biocides is not sustainable. How are they made? Who gets poisoned making them? Later...What happens to them in a landfill? What do they do to our water, oceans, streams? Bleach, Oil, Gas, Coal, Paint, Make Up, Cleaning Fluids, Anti Biotic Pumped-Factory Farmed Meat. The fact is the USA produces ever increasing amounts of poison every year. All of this poison is supposed to make our lives easier, more convenient. But all it ever does is make someone else rich! And all the rest of us suffer, exhausted and worked to the bone! Enough!