Crawlspace Mold

A moldy crawlspace is most often detected by technicians doing service work and by homeowners smells a hard to find musty smell in their homes. Locating mold in a crawlspace can be tricky due to a combination of lowlight and the presence of so many little nooks and crannies for the mold to hide.

Causes are near always attributed to water presence in some form or another. Whether moisture is pooling or condensing is often the concern in determining the source and location of any mold or moldy smells. It is the prevention and repair of the cause of these leaks that is the determining factor in preventing mold or moldy smells in the future. Simply placing plastic over the affected area will only give the moisture another substrate to condense on. This is why many crawlspaces that have been sealed without treating the water issues so often experience rotted wood corroded foundation walls and musty mold smells.

Can I Spray Chlorine Bleach On Mold To Kill It?

Spraying moldy surfaces with bleach can work, however the surface must be solid and non-porous.   Counter tops, certain tile floors, bathroom tiles, glass etc. can be cleaned this way.  The grout between tiles, walls or any porous surface or wood-based building products, including paneling, studs, etc. are not candidates for chlorine based products.

There are a number of new mold and mildew related products on the market, and each have their own unique instructions and intended effects.  Read the product label carefully to make certain it is appropriate for your particular problem and then follow the directions exactly.  This is the only way to be certain your efforts have a chance for success.  Of course, calling mold remediation professionals when it come to mold remediation is always a good alternative to the “hit or miss” reality of do-it-yourself attempts.

Is Mold A Health Hazard For Me Or My Family?

Fortunately, most people are not overly sensitive to the mycotoxins produced by some active mold colonies.  While the “smell” of mold growing is not pleasant for anyone, most people do not require medical treatment as a result of mold exposure.  There are, however, a significant number of exceptions.

According to the World Health Organization study from 2009,  “Exposure to microbial contaminants is clinically associated with respiratory , symptoms, allergies, asthma and immunological reactions.”  In addition the report states,  “The most important means for avoiding adverse health effects is the prevention (or minimization) of persistent dampness and microbial growth on interior surfaces and in building structures.”

Since all of us have the capacity to develop reactions to mold toxins over time, living with mold in the house means assuming unnecessary health risks for families.  When it comes to basements, “clean them up and dry them out” is an appropriate motto!

Moldy Basement Smell

It is very common for homeowners to have a moldy or mildewy smell in their basement that is very hard to locate. There can be many causes of such smell and the tracking alone can make some a little queasy. Oftentimes the mold is in small recessed areas that are very difficult to locate without either very specific equipment or a highly experienced person inspecting the area. Mold is often found behind finished walls. This makes location limited to foundation exposure in basements or some wall removal in upper floors. Sometimes these problems can only be determined by having the area looked over by professionals. Basement Detective is the DC area company capable of determining the source of the condition(s) that can cause mold growth. There are only a few independent companies like this one that offer services such as finding and repairing the cause(s) for homeowners and contractors.

How To Prevent Mold In My Home

There are 3 important steps to preventing mold growth in your home.
1. Detect it
2. Remove the mold
3. Remediate the water source

Detect it
If you smell mold, you have mold. The first step is finding the source of the smell. Once this is located and narrowed down to a relatively easy to inspect spot, then you are ready for step two.

Remove the Mold
Removing mold can be very messy and even dangerous if there is a large amount of it. Areas of heavy mold growth over a few square feet should be removed under containment or at least by a mold professional. It is possible to clean mold off of surfaces that are not porous such as glass and plastic, but it will not be possible to clean porous materials  to a mold free level. Materials such as drywall, cloth, leather, shoes, basically any organic material will not clean very easily. If these materials cannot be put in a deep cycle cleaning machine, like a washer, then there is little hope of removing all of the mold.

Remediate the Water Source

The removal of the actual source of the water is the primary goal in preventing mold growth. If the source of water is removed or cut off, the mold will not continue to grow. It is true that mold will still remain alive after the water is gone, but it will not continue to grow. This is why, however, removal of moldy materials is only one of the  important steps. Many mold removal and mold remediation companies do not perform this crucial step of water remediation and the mold only returns.

Why Basements Tend to Smell

There are many factors that can lead to mildew or moldy smells in a basement. The first and most common is the presence of water either as moisture or excessive humidity. The next is a  lack of air movement. If these two are combined there will either be a mold build-up or the likelihood of one.

Most commonly mildewy or moldy basement smells are due to wet foundation walls and the presence of finishing materials such as carpet and drywall. The building materials are a constant food supply and will aid mold growth if given enough water or dampness.

There are two basic ways to remove or prevent a moldy smell.
1. The prevention of the water or moisture present. This is the most desired cure and the best starting point to eliminate or prevent mold growth and, of course, the moldy smell. Water elimination  may involve plumbing repairs, the waterproofing of either the building’s interior or exterior below-grade areas, or the balancing of the HVAC system,  among others.

2. The removal of building materials.  While this is a less desirable approach, removal of the food that is aiding the mold growth (if the water problem cannot be solved) will slow or prevent further mold growth even if the cause of the moisture problem is not addressed.

EPA Mold Course

The Environmental Protection Agency has developed an online tutorial course as an overview to mold prevention and remediation. This course is meant to cover basic information for property owners and contractors and should not be used in lieu of a state-approved certification course. The course is based on the EPA’s guide “Mold Remediation in Schools and Commercial Buildings”. People who may find this information of value include public and environmental health professionals including, but not limited to, building managers, custodians, remediators, and contractors.

To take the basic knowledge quiz on mold, continue to the Pre-test.

This is the first of a series of mold publications circulated by the Environmental Protection Agency. More information and resources on mold can be found at the main website for the U.S. Environmental Protection Agency. All images are used for presentation and educational purposes and can be located in the EPA’s Image Library.

Suggested Study Schedule: We suggest reviewing one lesson a day. At the end of each chapter, take the knowledge test to be sure you are understanding the material. If you do not score with an 80% accuracy, you should review the material and retest.

Asthma and Allergic Diseases

Asthma and Allergic Diseases

  • American Academy of Allergy, Asthma & Immunology (AAAAI)
    (800) 822-2762

    Physician referral directory, information on allergies and asthma
  • Asthma and Allergy Foundation of American (AAFA)
    (800) 7-ASTHMA (800-727-8462)
    Information on allergies and asthma
  • American Lung Association (ALA)
    (800) LUNG-USA (800-586-4872)
    Information on allergies and asthma
  • Asthma and Allergy Network/Mothers of Asthmatics, Inc. (AAN*MA)
    (800) 878-4403 or (703-641-9595)
    Information on allergies and asthma
  • National Institute of Allergy and Infectious Diseases (NIAID)
    (301) 496-5717

    Information on allergies and asthma
  • National Jewish Medical and Research Center
    (800) 222-LUNG (800-222-5864)

    Information on allergies and asthma

Information found at Environmental Protection Agency.

Antimicrobial Information Hotline

Antimicrobial Information Hotline
(703) 308-0127/(703) 308-6467(FAX)
Monday-Friday 8:00 AM – 5:00 PM EST

The Antimicrobials Information Hotline provides answers to questions concerning current antimicrobial issues (disinfectants, fungicides, others) regulated by the pesticide law, rules and regulations. These cover interpretation laws, rules, and regulations, and registration and re-registration of antimicrobial chemicals and products. The Hotline also provide information health & safety issues on registered antimicrobial products, product label and the proper and safe use of these antimicrobial products.

Information found at Environmental Protection Agency.

Beware Organic Debris (Mulch) Around Home

“Depending on the areas where surveys are conducted, sterile mycelia and the fungi of the genera Cladosporium, Penicillium, Alternaria, Epicoccum, Aspergillus, Pullularia, and Drechslera are most commonly encountered. Studies have also shown that poorly maintained landscaping, high shade levels, and large amounts of organic debris near the home (including ivy, compost, and bark chips) are highly correlated with the accumulation of indoor molds. Also, the development of mold in room-air humidifiers, cold-mist vaporizers, and air-conditioning systems has received much recent attention.”
Quoted from

Fungal Toxins

Fungal toxins, or mycotoxins, are biomolucules produced by fungi which can be toxic to animals and humans. Many fungal toxins interfere with RNA synthesis and can damage DNA. Aspergillus Flavus and Aspergillus parasiticus are strong carcinogens. Trichothecenes produced by Stachybotrys chartarium and Asperigullus versicolor were present in most samples of tested material and dust from buildings with current or past water damage. Of fifteen samples, nine of these came from buildings without visible damage or mould.

Aspergillus mold culture.



(Photo available through Environmental Health Perspectives)


More Information available at World Health Organization.

Enforcing Codes and Regulations in your Building or Rental

If you are unsure about mold issues in your building or home and your landlord refuses to take responsibility towards remediating the problem, you do have options.  Contact your local board of health or housing authority. Health codes fall under state and local, not federal jurisdiction. Contact your state or county health department in order to read up on local codes and regulation in order to know your legal rights.

More information available at Center for Disease Control.

Mold Remediation–Key Steps

Mold Remediation – Key Steps

  • Consult health professional as appropriate throughout process
  • Select remediation manager
  • Assess size of mold problem and note type of mold-damaged materials
  • Communicate with building occupants throughout process as appropriate to situation
  • Identify source or cause of water or moisture problem
  • Plan remediation, adapt guidelines to fit situation, see Table 1 & Table 2
  • Select personal protective equipment (PPE)
  • Select containment equipment
  • Select remediation personnel or team
  • Choose between outside expertise or in-house expertise
  • Remediate
  • Fix water or moisture problem
  • Clean and dry moldy materials See Table 2
  • Discard moldy items that can’t be cleaned
  • Dry non-moldy items within 48 hours See Table 1
  • Check for return of moisture and mold problem
  • If hidden mold is discovered, reevaluate plan

Information found at Environmental Protection Agency.

Fungal Allergens

Fungal species produce Type I allergens. Common indoor/outdoor species such as Alternaria, Pen icillian, Aspgillus, and Cladosporium cause allergic repertory disease, especially asthma.  Pencillian and Aspgillus are also well-known causes of Type III allergens. And in high concentrations, Type IV allergens, hypersensitivity pneumonitius,  are seen.  Inside airways, germination and mycelia growth occur most which release greater amounts of spores, hyphae, and fungal fragments. Because these are well adapt at airborne dispersal, these are the most harmful fungal issues.

More Information available at World Health Organization.

Mold Clean Up

NCSU article details how to prevent and clean up after a flood or mold infestation.

NCSU article

Mold Prevention Tips

Mold Prevention Tips from the EPA

  • Fix leaky plumbing and leaks in the building envelope as soon as possible.
  • Watch for condensation and wet spots. Fix source(s) of moisture problem(s) as soon as possible.
  • Prevent moisture due to condensation by increasing surface temperature or reducing the moisture level in air (humidity). To increase surface temperature, insulate or increase air circulation. To reduce the moisture level in air, repair leaks, increase ventilation (if outside air is cold and dry), or dehumidify (if outdoor air is warm and humid).
  • Keep heating, ventilation, and air conditioning (HVAC) drip pans clean, flowing properly, and unobstructed.
  • Vent moisture-generating appliances, such as dryers, to the outside where possible.
  • Maintain low indoor humidity, below 60% relative humidity (RH), ideally 30-50%, if possible.
  • Perform regular building/HVAC inspections and maintenance as scheduled.
  • Clean and dry wet or damp spots within 48 hours.
  • Don’t let foundations stay wet. Provide drainage and slope the ground away from the foundation.

Information found at Environmental Protection Agency.


This article on slime mold, myxomycetes, covers it’s life cycle and classification.

Island Nature article

Physicians for Health Issues Resulting from Mold

If you are concerned about health problems that are associated with exposure to mold, you should first contact your family or general health care provider inorder to determine if you need a refer to see a specialist. Specialist include allergists, physicians who treat mold allergies, or an infectious disease physician, who treats mold infections. If the infection is located in the lungs, a pulmonary physician might be needed.

More information available at Center for Disease Control.

Guidelines from World Health Organization

Review from Executive Summary of The World Health Organization’s publication, The Guidelines for Indoor Air Quality: Dampness and Mould:

On the basis of this review, the following guidelines were formulated. Persistent dampness and microbial growth on interior surfaces and in building structures should be avoided or minimized, as they may lead to adverse health effects.

  • Indicators of dampness and microbial growth include the presence of condensation on surfaces or in structures, visible mould, perceived mouldy odour and a history of water damage, leakage or penetration. Thorough inspection and, if necessary, appropriate measurements can be used to confirm indoor moisture and microbial growth.
  • As the relations between dampness, microbial exposure and health effects cannot be quantified precisely, no quantitative health-based guideline values or thresholds can be recommended for acceptable levels of contamination with microorganisms. Instead, it is recommended that dampness and mould-related problems be prevented. When they occur, they should be remediated because they increase the risk of hazardous exposure to microbes and chemicals.
  • Well-designed, well-constructed, well-maintained building envelopes are critical to the prevention and control of excess moisture and microbial growth, as they prevent thermal bridges and the entry of liquid or vapour-phase water.
  • Management of moisture requires proper control of temperatures and ventilation to avoid excess humidity, condensation on surfaces and excess moisture in materials. Ventilation should be distributed effectively throughout spaces, and stagnant air zones should be avoided.
  • Building owners are responsible for providing a healthy workplace or living environment free of excess moisture and mould, by ensuring proper building construction and maintenance. The occupants are responsible for managing the use of water, heating, ventilation and appliances in a manner that does not lead to dampness and mould growth. Local recommendations for different climatic regions should be updated to control dampness-mediated microbial growth in buildings and to ensure desirable indoor air quality.
  • Dampness and mould may be particularly prevalent in poorly maintained housing for low-income people. Remediation of the conditions that lead to adverse exposure should be given priority to prevent an additional contribution to poor health in populations who are already living with an increased burden of disease.

Schild – Vereinte Nationen-Campus (UN-Campus) Görresstr. 15 in Bonn. United Nations Educational Scientific and Cultural Organization (UNESCO-UNEVOC), World Health Organization (WHO-ECEH), United Nations University (UNU-EHS). (Photo by Michael Z.)

Full publication available at World Health Organization.

Mold Remediation in Schools

Commercial buildings and schools are areas of concern for public health. Mold detection and remediation is pertinent in order to insure the quality of health, especially for our children and elderly populations. When mold is found in public buildings, adverse health problems may be reported by occupants, employees, and general populations. Health issues may include allergies, skin irritations, and breathing problems. Serious problems may occur in circumstances where 1) children or elderly individuals, 2) individual with low immunity systems, 3) individuals with other health issues such as asthma, or 3) toxic molds are present.

Mold in School.

(Photo available through Mold News January, 2003 issue)

Article information found at Environmental Protection Agency.