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And he shall look on the plague, and, behold, if the plague be in the walls of the house with hollow strakes, greenish or reddish...break down the house, the stones of it, and the timber thereof, and all the mortar of the house, and carry them forth out of the city.

This passage from the Book of Leviticus, which reads like an awkward directive from a manual on mold remediation, is an indication that mold has been troubling mankind since Biblical times. Although mold has been an issue for centuries, only in recent years has it grabbed the spotlight. This is due to high-profile lawsuits, such as the Ballard case in Texas, in which a family claimed that mold in their home was the source of their myriad health problems. The Ballards won an initial $32 million judgment against their insurance company, which later was reduced to $4 million.

The Ballard case is only one example of the onslaught of litigation that has targeted defendants, including contractors, architects, insurers, building owners, and property manager. As health problems have become connected to mold exposure, mold has been elevated beyond a simple property loss issue, and many property owners and tenants have growing concerns about toxic mold exposure.

In reality, the relationship between health and mold growth in buildings is poorly understood. It appears, however, that short-term health implications and the possibility of long-term health effects do exist.

In the insurance industry, mold is not always part of a standard insurance policy. In instances where it is included in policies, the trend is toward instituting dollar caps on coverage, in order to minimize pay outs. It is unknown whether waivers and exclusions of mold insurance coverage will continue to stand up in court. Some argue that it is difficult to make a distinction between mold due to a "covered peril," such as a broken pipe, and mold growth resulting from other sources, such as excess humidity, condensation, or building defects.

At this point, there are still more questions about mold than answers. However, many lessons have been learned about proper building practices, preventive maintenance, accurate testing, and remediation procedures that can help curb mold losses.

Examining Building Practices

Post-World War II Construction practices are partially to blame for mold problems, due to the use of building products such as carpets, fiberglass, and gypsum board. These materials are porous and contain nutrients that support mold growth, whereas plaster and hardwood flooring, common construction materials prior to WWII, are much less susceptible. It is important to remember, however, that all building materials, both organic and inorganic, can become breeding grounds for mold if improperly installed. Careful planning and attention during the construction phase will reduce the changes of costly mold and moisture problems down the road.

First, a site should be properly graded before construction begins and all materials should be kept dry during construction. Although this seems like common sense, bad weather is not the only threat to materials during this phase. Condensation on cold concrete slabs and foundations or non-insulated building corners has provided sufficient moisture in some cases to cause mold growth.

Insulation under concrete can prevent condensation, which is a particular issue in hot, humid climates. Also, moisture barrier products can prevent moisture from entering low areas. These products, often sprayable liquids, form seamless membranes that shield porous building materials from moisture penetration. If moisture is noticed in the basement prior to the HVAC installation, the basement should be properly dehumidified. Another action that can prevent future mold problems is to allow wood and concrete adequate time to dry before installing plywood, carpet, tile, etc.

When it comes to installing carpet in commercial settings or homes, common sense should rule. Carpet should not be installed in a health-care of food setting, such as cafeteria, restaurant, or kitchen. Liquid spills and food can be difficult to clean up, and excess moisture can lead to mold growth. However, there may be minimal risk in installing carpet in a second floor bedroom or office, and acoustic and cost considerations may make carpet the best choice under certain circumstances.

Gypsum board, especially when used in basements, should be installed approximately an inch off the ground to prevent water from wicking up in the event of minor leaks or floods. Gypsum board paper-faced products used as exterior sheathing present unique problems. If the board becomes moldy and remediation is necessary, the exterior of the building may have to be removed to allow access to the gypsum sheathing, a colossal undertaking and one example of why vigilance during construction is important.

O&M Plans

A well designed operation and maintenance plan is one key to preventing mold damage and property loss. These plans ensure that building managers, owners, and maintenance workers are aware of the specific actions they must take to prevent and, should the need arise, promptly address mold and moisture problems. The value of these plans increasingly is being recognized across the industry.

In the commercial insurance field, some carriers require that the building be evaluated by mold consultants initially, a requirement for purchase and insurance coverage in some cases. Additionally, some require that the building management maintain an O&M plan designed to prevent water instruction. Failure to follow the plan could result in loss of coverage or added costs.

Unfortunately, there is no standard O&M that works for every building. To be truly effective, an O&M must be tailored to the individual building, existing building systems, and the climatic region. Humid climates will have very different building pressurization and HVAC needs that dry environments. Buildings in these humid regions, such as the southeastern United States, should be positively pressurized and should have moisture barriers designed to minimize moisture intrusion. An O&M plan would include special focus on monitoring moisture in the basement and inspection of the integrity of the building envelope.

In the Northeast, ice damming and moisture condensation are problems, but can be combated with well-designed attic ventilation and well maintained roofs. Colder climates also suffer frozen pipes that can burst, causing water damage. The roof, attic, and plumbing system in colder climates should be inspected regularly, especially during winter months.

Also of importance: if a building in this climate is to be vacant for an extended period of time during the winter, the water system should be shut down and drained. If the water system remains turned on, pipes must be insulated and kept warm, and someone should check on the building frequently to ensure that an event, such as a pipe break, has not occurred.

In general, an O&M plan includes common-sense inspections carried out by maintenance staff or outside contractors. Roofs, HVAC systems, building envelopes, crawl spaces, basements, attics, and plumbing and drainage systems should be inspected and evaluated. Any standing water, visible growth, or water stains should send up red flags. Disaster response procedures should be outlines clearly, and a list of vendors with expertise in inspection and remediation is helpful to have on hand.

Moisture problems uncovered during inspections may be small and cost little to nothing to fix, such as moving a water cooler to a tile surface rather than allowing it to remain on carpet, where water damage is evident. Larger problems may require outside help and may be more costly, but it is always better to address the problem immediately rather than allowing it to spiral out of control, which could cost even more money later.

When Mold Happens

Approximately 200,000 species of mold are in existence, and only about three dozen species are known to contain mold toxins, the black mold that has caused widespread fear and attention and is linked to varying health issues. However, even on-toxic mold can cause allergies, irritation, and asthma. In rare cases, immune-suppressed individuals can develop opportunistic infections from specific mold species. Therefore, it is important to have mold problems eliminated quickly and effectively.

Remarkably, at this time, there is no federal, state, or local licensing of mold investigators or remediation contractors. Hiring incompetent people or companies to handle mold issues can have catastrophic consequences. Ineffective remediation work could release mold spores into the air, worsening the problem. In school, health-care, or residential settings for example, occupants may be very young, elderly, or have preexisting conditions that could be exacerbated by shoddy clean-up jobs.

What should you look for in a competent remediator? Field experience and knowledge of building systems is the short answer. A mold expert may hold many different certification programs and titles, but those are not the most important criteria in deciding whom to hire. A mold expert can be Certified Industrial Hygienist (CIH), a microbiologist, or a Certified Microbial Consultant/Investigator (CMC/CMI), but be sure to look past the degrees, certifications, and fancy titles and ask questions about a candidate's field experience.

It also is helpful to be aware of some common mistakes that help identify lack of experience. For example, a novice investigator is likely to overcompensate by collecting more samples than needed. Unnecessary sampling can drive up the cost of the investigation and, often, is not valuable in establishing the cause or the age of the water loss.

Another mark of inexperience is the collection of airborne fungal samples when visible mold growth is present. Although required by some insurance companies, if mold growth is visible, little is gained from sampling airborne fungi. Airborne levels are altered with temperature, relative humidity, and vibration, and air sampling does not provide assessment information unless mold growth is not visible.

Evaluation of whether mold exists in a wall cavity presents a challenge to many new investigators. Is destructive testing required, and will the testing affect the building occupants? How and where does one test in order to minimize the damage and still be confident that the testing is thorough? The industry does not have clear-cut answers to these questions, and picking the best options can be daunting for an unseasoned investigator.

Solving the Problem

Why have mold losses been so difficult to control? One possible answer is that, because to prevent and quickly solve mold problems, a commitment must be made by all parties: the architect, construction company, building owner, manager, and tenants. Everyone involved must be dedicated, and this is difficult to achieve for obvious reasons.

However, more people are now aware of not only how dangerous mold can be, but also what actions can be taken to prevent and address problems. O&M plans are gaining momentum, smarter construction practices are being implemented, and building supply companies are working to develop moisture-resistant materials that may eventually replace what contractors are using today.

The battle against mold has been waged for centuries and, despite a sometimes frustrating struggle, experts are developing new and inventive ways to keep the slimy beast at bay.

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EFI Global is a full-service Engineering, Fire Investigation, Environmental, Health and Safety, and specialty consulting firm. Over the last four decades, they have grown from a boutique firm to become a recognized leader in engineering failure analysis, origin and cause investigations, and environmental consulting. This expertise coupled with the extensive coverage of our 27 national offices, more than 400 professionals, and global work abroad capability allows EFI Global to deliver timely responses that consistently meets their clients' expectations.

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