This Summer Prevent Pests by Reducing Moisture Outside of Your Home

By Marcia Anderson

Clogged gutters provide the standing water that mosquitoes need for egg laying and larval growth

Clogged gutters provide the standing water that mosquitoes need for egg laying and larval growth

Like most suburban dwellers, I spent the past few weekends trimming vegetation, mowing the lawn and making sure gutters and other areas around the house were clean of debris and standing water. I soon realized that the mosquito, black fly, and other insect populations were blooming along with the flowers. But where were all of these pests coming from?

Bugs and rodents go wherever there is water. If you have a water leak in or under your house, and the wood stays wet, it will attract pests such as: wood lice, carpenter ants, and termites. Pests that eat wood are particularly interested in moist wood because it is easier for them to chew. They also rely on the moisture in the wood as a source of water. Termites and carpenter ants are known for burrowing through wood and forming nests inside the wood structures. Once holes are made because pests have found wet, weakened spots, rodents may enter the home through those gaps. Have your home’s crawlspaces checked for pests when plumbing problems are detected.

Insects and other small pests need to draw life-sustaining moisture from their surroundings, so they avoid dry places and are attracted to moist areas. If the soil around your house is dry, it’ll be less attractive to insects, spiders, centipedes and other pests.

Buckets provide great habitats for mosquito breeding

Buckets provide great habitats for mosquito breeding

Downspouts and gutters are the first places to look for breeding pests. Termites thrive in the moisture often found around your home’s downspouts. Direct water away from your home by turning the downspouts away from the house and use downspout extensions (splash blocks) to disperse rainwater and prevent soil erosion around the foundation. Also watch for leaks and clogs in your gutters that may eventually lead to water damage. Make sure all other drains, including the air conditioner drain lines, flow away from the home and that the pipes extend at least two feet from the foundation.

I found a few standing water sources on my property.

  • The drainage holes on the bottom of a planter were clogged with leaves and collecting rain water.
  • My grandson’s plastic pail and other play equipment had been forgotten outside and had filled with rainwater and mosquito larvae.
  • One of my sprinkler system’s underground lines was leaking, creating a puddle in the yard.
  • Water was collecting in a cavity in one of our trees.

Everyone should take steps to eliminate places where water collects outdoors, such as: tires, garbage cans, tree holes, buckets, wash tubs, even table umbrella stands, etc. This will not only eliminate mosquito breeding habitats, but also water sources for cockroaches and termites. Empty out any water you find to eliminate this problem.

I also had to remove some mulch that was piled too close to the house and trimmed the plants that were growing too close to the siding.  Mulch traps moisture and should be raked away from windowsills, siding and any other wood. Keep a two-foot pest-free strip around the building by trimming branches, and making sure mulch doesn’t touch the foundation.

Tree cavities provide an unexpected breeding spot for mosquitoes

Tree cavities provide an unexpected breeding spot for mosquitoes

Plants growing against the house will also keep siding damp so trim back bushes and trees. Make sure that the soil is sloped away from the house at least six inches every 10 feet. This will reduce soil dampness near your foundation and keep your basement drier.

Lastly, monitor irrigation systems. Ensure sprinklers are adjusted to spray away from the foundation walls and the house.

Be PestWise! Regular maintenance and sanitation are key components of a smart, sensible and sustainable pest management program. Recognizing the value of pest prevention is an important first step. Preventing the accumulation of moisture outside of your home protects you from pests, saves water, and helps the environment. Visit EPA’s website for more information on controlling pests in and around your home.

About the Author: About the Author: Marcia is with EPA’s Center of Expertise for School IPM in Dallas, Texas. She holds a PhD in Environmental Management from Montclair State University along with degrees in Biology, Environmental Design, Landscape Architecture, and Instruction and Curriculum. Marcia was formerly with the EPA Region 2 Pesticides Program and has been a professor of Earth and Environmental Studies, Geology, and Oceanography at several universities.

Editor's Note: The views expressed here are intended to explain EPA policy. They do not change anyone's rights or obligations. You may share this post. However, please do not change the title or the content, or remove EPA’s identity as the author. If you do make substantive changes, please do not attribute the edited title or content to EPA or the author.

EPA's official web site is www.epa.gov. Some links on this page may redirect users from the EPA website to specific content on a non-EPA, third-party site. In doing so, EPA is directing you only to the specific content referenced at the time of publication, not to any other content that may appear on the same webpage or elsewhere on the third-party site, or be added at a later date.

EPA is providing this link for informational purposes only. EPA cannot attest to the accuracy of non-EPA information provided by any third-party sites or any other linked site. EPA does not endorse any non-government websites, companies, internet applications or any policies or information expressed therein.

When it Rains, it Molds: Part 2 of 2

By Marcia Anderson

Schools can harbor mold that triggers asthma in students.

Schools can harbor mold that triggers asthma in students.

When I was in EPA Region 2 (New York, New Jersey, Puerto Rico and the Virgin Islands) I visited several schools that had questions about mold. This prompted a follow-up discussion with Mark Berry, EPA’s Region 6 (Serving Arkansas, Louisiana, New Mexico, Oklahoma, Texas and 66 Tribes) Indoor Air Quality Coordinator about common mold questions resulting from these visits. An earlier blog looked at general questions about mold and moisture. Here, we focus on these issues in schools.

What are the most impacted areas in school buildings?

Areas without adequate air flow by themselves are not, necessarily the issue – it is areas where it is damp or humid and the airflow isn’t adequate enough to help dry up the moisture. Problem areas may be in the walls behind restrooms, kitchens, gyms, facility manager closets, near air conditioners, compressors and in damp basements. Moisture problems in schools may also be associated with delayed or insufficient maintenance due to budget and other constraints. Temporary structures, such as trailers and portable classrooms, have frequently been associated with moisture and mold problems. Most respiratory issues are associated with poor ventilation or outdated HVAC units. Mold is often targeted as the cause for illness, but, in fact, the mold is an indicator of moisture.

One area that is often impacted by mold and moisture problems in schools are gym locker rooms. Do you have any advice for school facility managers?

It is common for mold to grow on and around areas that are continuously wet. The moisture has a tendency to increase the relative humidity levels in a building, providing the perfect environment for mold and mold spores to grow.

  • Vent showers and other moisture-generating sources to the outside;
  • Control humidity levels and dampness by using air conditioners and de-humidifiers to provide adequate ventilation.
  • Maintain indoor humidity levels between 30-60 percent.
  • Students should remove clothing from their gym lockers at least weekly, and damp laundry, such as towels, should be removed daily.

For existing mold, the first step is to eliminate the moisture source, then take appropriate steps to clean it up. The EPA does not encourage the use of harsh chemicals for mold clean-up. Soap and water will suffice. These measures, along with monitoring for adequate ventilation, locker checks and educating students about the importance of following these guidelines, will go a long way to decreasing mold in your school.

Mold and moisture problems in the basement of an older school.

Mold and moisture problems in the basement of an older school.

What do we do if we suspect hidden mold?

Investigating hidden mold problems may be difficult and will require caution when it involves disturbing potential sites of mold growth. If you believe that you may have a hidden mold problem, consider hiring an experienced professional.

What can building facility managers do to decrease the incidence of mold in their buildings?

EPA’s guidance is solutions based – to focus on the source of the moisture that feeds the mold. The three principles of mold remediation are:

  1. Fix and eliminate the moisture source.
  2. Clean and remove mold and mold spores. In many cases detergent and water will be sufficient – there is no need to use harsh chemicals that may endanger your health. Follow all manufacturer’s directions when using cleaning products.
  3. Dry out the area. If you continue to see mold growing, you have not eliminated the moisture source and should repeat step 1.

Does carpet cause mold or related allergy problems in schools?

Carpet use in schools provides a decrease in noise, falls and injuries. Mold problems can be encountered with carpet and many other materials if the school has any type of water intrusion or moisture problem, such as a leaky roof. If carpeting remains damp, it can become a primary source for microbial growth, which frequently results in adverse health effects. Carpet and other furnishings that become significantly water damaged should be removed and discarded. Use care to prevent excess moisture or cleaning residue accumulation and ensure that cleaned areas are dried quickly. In areas where there is a perpetual moisture, do not install carpeting (i.e., by drinking fountains, by classroom sinks, or on concrete floors with leaks or frequent condensation).

How does mold affect asthma?

Molds can trigger asthma episodes in sensitive individuals with asthma. People with asthma should limit contact with and exposure to areas contaminated with a mold presence. However, remember that molds are a natural part of the environment – and it is impossible to totally avoid mold for asthmatics. EPA provides very useful information on mold and asthma.

How does mold remediation compare to Integrated Pest Management (IPM)?

IPM and mold remediation are both based on the principle of limiting sources of the primary needs for life – but they are very different practices. Molds are microscopic fungi that grow best in damp places such as kitchens, bathrooms and basements. Mold has the same basic needs as any pest: 1. Mold needs a surface to grow on; 2. Food (paper, wood, carpet, food, insulation or other organic fibers); and 3. Water (moisture to germinate and grow). IPM is similar, in that it employs common sense strategies to reduce sources of food, water and shelter for pests in your school buildings. If just one of the essential components that a pest needs to survive can be removed, then the pest cannot survive. In the case of mold, remove the moisture. Mold problem solved.

For more information on controlling mold and moisture, visit www.epa.gov/mold

About the Author: Marcia is with EPA’s Center of Expertise for School IPM in Dallas, Texas. She holds a PhD in Environmental Management from Montclair State University along with degrees in Biology, Environmental Design, Landscape Architecture, and Instruction and Curriculum. Marcia was formerly with the EPA Region 2 Pesticides Program and has been a professor of Earth and Environmental Studies, Geology, and Oceanography at several universities.

Editor's Note: The views expressed here are intended to explain EPA policy. They do not change anyone's rights or obligations. You may share this post. However, please do not change the title or the content, or remove EPA’s identity as the author. If you do make substantive changes, please do not attribute the edited title or content to EPA or the author.

EPA's official web site is www.epa.gov. Some links on this page may redirect users from the EPA website to specific content on a non-EPA, third-party site. In doing so, EPA is directing you only to the specific content referenced at the time of publication, not to any other content that may appear on the same webpage or elsewhere on the third-party site, or be added at a later date.

EPA is providing this link for informational purposes only. EPA cannot attest to the accuracy of non-EPA information provided by any third-party sites or any other linked site. EPA does not endorse any non-government websites, companies, internet applications or any policies or information expressed therein.

When it Rains, it Molds

Part 1 of 2

By Marcia Anderson

Mold spores up close

Mold spores up close

When I went back home recently to visit my family, I noticed a number of mold spots on the ceiling in multiple rooms. A result of roof water damage from the winter ice and snow the northeast experienced this year. This prompted me to have an interview with Mark Berry, EPA’s Indoor Air Quality Coordinator for Region 6 (serving Arkansas, Louisiana, New Mexico, Oklahoma, Texas and 66 Tribes). Here are his responses to some common questions about mold and moisture.

  1. What is it that many people misunderstand about mold? It is important to view mold, not as a mold issue, but as a moisture issue. People think that mold is a hazardous material. Most people do not realize that mold and mold spores are all around us. Molds live in the soil, on plants, and on dead or decaying matter. Outdoors, molds play a key role in the breakdown of leaves, wood, and other plant debris. Molds produce tiny spores to reproduce, just as some plants produce seeds. These mold spores can be found in both indoor and outdoor air, and settled on indoor and outdoor surfaces. When mold spores land on a damp spot, they may begin growing. It is important not to provide the moist environment mold needs to grow.The solution to the problem is to find and eliminate the moisture source first, and not focus only on the mold. Removing the mold alone does not solve the problem. If the water remains, new mold will grow in the same area.
  1. Mold spreads in the damp area behind a sink

    Mold spreads in the damp area behind a sink

    Should I use bleach to clean up my mold? In most cases using bleach isn’t necessary. Soap and water will often do the trick. Using bleach or some other harsh chemical cleaners can create a breathing hazard for you. If you choose to use disinfectants or biocides, always follow manufacturer’s directions, ventilate the area and exhaust the air to the outdoors. Never mix chlorine bleach solution with other cleaning solutions or detergents that contain ammonia because toxic fumes could be produced.

  1. Can I just paint over the mold? Many people see mold, spray some chemical then paint over it, thinking that will solve the problem. Mold can grow between the paint and the wall in all directions. The paint merely acts as a temporary cover-up. The issue with the paint is that it traps moisture between the paint and the wall, further aiding and abetting the growth of mold. Fix the source of the moisture first, and then take the appropriate steps to clean the affected area or remove it altogether.
  1. What are your most compelling mold calls? Landlord /tenant disputes over mold are our most frequent calls. We attempt to educate and make suggestions for remediation that may be used or not used by the caller’s choice. Callers need to consider the problem as both a building water issue as opposed to a mold issue. This strategy addresses the cause of the mold infestation and not the symptom. We try to get to the root cause of the problem and ease the caller’s concerns. Mold is essentially the result of water damage.
  1. Is there more mold in different parts of the country? Yes, and No. We have more mold inquiries in humid areas because the mold continually gets fed more moisture which allows it to flourish. However, mold can grow everywhere and can exist in a broad range of temperatures and humidity levels. Although moisture is necessary for growth there are molds which prefer drier environments and would need much less than other types to survive.
  1. Mold can be a variety of colors

    Mold can be a variety of colors

    What are your most frequent calls? “I’ve got mold problems can you do something to help me?” EPA Region 6’s Indoor Air Quality program (IAQ) is a voluntary program primarily responsible for conducting outreach and educating the public about indoor environmental issues, including health risks and the means by which human exposures can be reduced. IAQ educates the public about indoor environmental pollutants and sources of pollution, including mold. However, EPA does not have any regulatory authority to control mold in private residences nor do we have the resources to inspect individual homes.

    The EPA does not conduct mold cleanups, but we do provide the education necessary to give people the strategy and empowerment needed to solve the problem. We recognize the health danger to schools, homes and places of work. The EPA is the technical lead in mold research from which many states and local agencies borrow.

  1. Is testing for mold necessary?
    In most cases, if visible mold is present, sampling is not necessary. Since no EPA or other federal limits have been set for mold or mold spores, sampling cannot be used to check a building’s compliance with federal mold standards. Remember that mold and mold spores are natural in the environment so any sampling will result in finding mold.

For more information on controlling mold and moisture, visit www.epa.gov/mold

About the Author: Marcia is with EPA’s Center of Expertise for School IPM in Dallas, Texas. She holds a PhD in Environmental Management from Montclair State University along with degrees in Biology, Environmental Design, Landscape Architecture, and Instruction and Curriculum. Marcia was formerly with the EPA Region 2 Pesticides Program and has been a professor of Earth and Environmental Studies, Geology, and Oceanography at several universities.

Editor's Note: The views expressed here are intended to explain EPA policy. They do not change anyone's rights or obligations. You may share this post. However, please do not change the title or the content, or remove EPA’s identity as the author. If you do make substantive changes, please do not attribute the edited title or content to EPA or the author.

EPA's official web site is www.epa.gov. Some links on this page may redirect users from the EPA website to specific content on a non-EPA, third-party site. In doing so, EPA is directing you only to the specific content referenced at the time of publication, not to any other content that may appear on the same webpage or elsewhere on the third-party site, or be added at a later date.

EPA is providing this link for informational purposes only. EPA cannot attest to the accuracy of non-EPA information provided by any third-party sites or any other linked site. EPA does not endorse any non-government websites, companies, internet applications or any policies or information expressed therein.

Moisture Control: A Key Factor for a Healthy Indoor Environment

EPA’s mission is to protect public health and the environment. While a large part of this mission involves protecting the air and water outdoors, we also need to make sure that people have the tools and information they need to keep the air clean in the areas where they spend up to 90 percent of their time – indoors.  And the agency is doing that through voluntary actions and information sharing, not regulations.

Some of the biggest threats to indoor air quality stem from moisture issues. Leaking roofs, plumbing problems, condensation issues, poor indoor humidity control, and lack of drainage around the base of buildings are commonly reported causes of moisture problems in the United States. Not only does excess moisture damage the structural integrity of buildings, it can increase people’s exposure to mold and other biological contaminants. Such exposure is associated with increases in the occurrence and severity of allergies, asthma and other respiratory illnesses. And, climate change will only worsen these issues as we see an increase in the frequency and intensity of severe storms and flooding that damages homes and buildings.

The good news is moisture problems in buildings can be controlled with steps that can be taken to make buildings more moisture resilient. For example, design landscaping to slope away from building foundations. Doing simple steps like this can prevent economic losses on multiple fronts by avoiding building damage as well as negative health impacts as it makes our indoor spaces healthier and more comfortable.

That’s why EPA pulled together experts from across the country to develop new, practical, state-of-the-art guidance for controlling moisture in buildings.  EPA recently published the result of that work, entitled, “Moisture Control Guidance for Building Design, Construction and Maintenance.” Encouraging voluntary actions to control moisture and other indoor contaminants will be a critical part of our climate adaptation strategy for ensuring healthy buildings as we continue to address our changing climate.

The key to controlling mold and many other indoor contaminants is moisture control.  It’s a simple concept, but it takes attention to detail to get it right. That’s why this practical guidance will be helpful to people who design, build or keep buildings working. Building professionals who incorporate the principles provided in this guide can enhance the health and productivity of Americans and the sustainability and resiliency of our communities. While this guidance is primarily for building professionals, EPA also offers mold and moisture control guidance for homeowners and residents at epa.gov/mold.

Editor's Note: The views expressed here are intended to explain EPA policy. They do not change anyone's rights or obligations. You may share this post. However, please do not change the title or the content, or remove EPA’s identity as the author. If you do make substantive changes, please do not attribute the edited title or content to EPA or the author.

EPA's official web site is www.epa.gov. Some links on this page may redirect users from the EPA website to specific content on a non-EPA, third-party site. In doing so, EPA is directing you only to the specific content referenced at the time of publication, not to any other content that may appear on the same webpage or elsewhere on the third-party site, or be added at a later date.

EPA is providing this link for informational purposes only. EPA cannot attest to the accuracy of non-EPA information provided by any third-party sites or any other linked site. EPA does not endorse any non-government websites, companies, internet applications or any policies or information expressed therein.