CONTAINING NOXIOUS MOLD
BY NADINE M. POST
Mold stinks. No argument. Feed the fungi, water it, keep it in the dark and it will prosper. Disturb it and it will attack. No arguments there, either. Beyond that, in the wars against the most prolific building pest of the 1990s, almost everything else is up in the air. One big exception The cost of abating extensive building mold growth--at best an irritant, at worst a killer--can be "astronomical."
"Mold mitigation is not an easy process or a specific science," says Thomas L. Hitz, operations vice president of Barton Malow Co., Southfield, Mich. Hitz should know. He dealt with claims against his firm, which eventually cost it $5 million, in one of the most infamous new-building-mold court cases in the U.S., which involved the Polk County courthouse project in Bartow, Fla.
"Not long ago, the industry was saying this was not a problem," says engineer Steven F. Goselin, vice president of Envirotech, a remediation contractor in Cambridge, Mass. That is not so anymore, he adds. Owners and their building teams are now realizing they have to deal with mold proliferation.
Still, "there is a fundamental misunderstanding about mold problems in a building," says Joseph W. Lstiburek, a consulting engineer-principal with Building Science Corp., Westford, Mass. "It's not a mold problem, it's a water problem," he adds.
Gary L. Luepke, principal engineer at The Trane Co., a La Crosse, Wisc.-based manufacturer of heating, ventilating and air conditioning systems, agrees "You've got to get rid of the root cause. If you don't, and you get rid of only the amplification site, I guarantee that within six weeks, you'll have the mold growth back."
Mold growth can be abetted by a number of factors, alone or in combination, including faulty design, construction, inspection, commissioning, operations and maintenance. Natural disasters--floods and storms--and freak accidents like sewage leaks, which are nearly impossible to protect against, can also trigger mold growth. "A building can get wet three ways," says W. lstiburek. "From the inside, outside or it can start out wet."
Buildings are perfect habitats for mold growth. They have lots of sources of food--everything from cellulose-based products to flaked skin will do. They have the appropriate temperature range--from 40-100¡F, and lots of dark crevices, nooks and crannies. And mold loves HVAC systems. Ductwork and ceiling plenums, aided and abetted by fresh air intakes and fans blowing air around a building, are tailor-made conduits for microbes--not to mention bacteria, like legionella, and volatile organic compounds. HVAC systems unwittingly send out armies of airborne microscopic spores into occupied spaces, where they can hit their unsuspecting human marks--primarily through inhalation. HVAC systems are also capable of sucking moist air into a building and then shutting down before the air is properly dehumidified.
"There are microbe-contaminated surfaces everywhere in a building," says certified industrial hygienist Patricia H. Heinsohn, senior managing scientist at Exponent, Menlo Park, Calif. It becomes an issue when there are high concentrations of mold spores in the air that degrade indoor air quality, she adds.
There are tens of thousands of types of the pesky microbe; at least three different illness categories linked to exposure to airborne mold; and as many human susceptibilities as there are fingerprints. Consequently, as it is impossible to set "safe" air concentration levels for individual molds, remediation guidelines are often based on the most toxic one, Stachybotrys atra.
Further clouding the issue, mold is not always the trigger of "sick-building" syndrome. "Discomfort and irritation is not exclusively a mold problem, but it happens with mold, too," says Joseph Q. Jarvis, a Salt Lake City medical doctor who is a consultant in public and environmental health.
At least with a public building, a mold problem is likely to become part of the public record. In private buildings, mold problems are "handled behind the scenes," says Goselin, because owners fear their buildings will be labeled and shunned. Abatement often "happens in the middle of the night on weekends, and nobody wants to talk about it," he says. In public, many of his clients won't even admit they know him.
Consulting engineer David Wojcieszak of the Stuart, Fla., firm that bears his name, says public buildings end up in the media because "proper protocol" for IAQ mitigation is not followed, and lawsuits are filed. To fix the problem, "the community hires lawyers first, not consultants," he says. Referring to another infamous Florida mold case involving the Martin County courthouse in Stuart, Wojcieszak says "The whole incident was driven by attorneys. It should be driven by building professionals."
With so much unsettled, mold amplification in buildings is rattling the public and inflaming the building team. Nostrils flare between doctors, hygienists and biologists--often called in to diagnose the problem and specify a cure--and engineers. There are "engineers running around giving medical diagnoses and doctors going around giving building diagnoses," says Lstiburek.
With so many variables, it's no wonder there is such a cacophony. And when there is a new or recently renovated building that develops mold problems, building teams point fingers at each other, the client and the operations and maintenance staff. When disputes can't be settled out of court--as in Polk and Martin counties in march the lawyers--draining bank accounts and raising blood pressure. "This is all very expensive," Heinsohn says. "Cost is always an issue and with litigation, the stakes are high." Heinsohn, often an expert witness, is currently investigating the Santa Clara County courthouse in San Martin, Calif., for mold growth (ENR 2/15 p. 14).
Roy S. Latka, president of Kaplan McLaughlin Diaz, the courthouse's San Francisco-based architect, declines to talk about it. But he does say architects are always vulnerable to lawsuits when a new building has problems. Responsible or not, "it costs a firm $200,000 to $500,000 just for legal fees," he says.
Mold investigations can range from some $3,500 to more than $1 million. But that's pennies compared with the potential cost of remediation, especially if full-scale containment, as in done in asbestos abatement, is required. The cost can escalate further if the building is stripped to its skeleton and largely reconstructed, as in Polk and Martin counties. Sources say remediation alone can cost as much as $150 per sq ft. And containment costs 10 times as much as just ripping something out or ordinary cleaning, says Goselin. He charges $75 per hour for an abatement supervisor and $65 per hour for a technician.
Goselin once quoted $2,000 to remove a 20 x 30-ft moldy carpet. Sensitive to mold because he himself was careless about wearing protective gear when doing estimates, he is serious about containment to avoid harming technicians, spreading spores and creating a bigger mess. Expensive or not, the real estate industry is "beginning to understand the importance of containment," he says.
Not everyone thinks building mold is a big deal. "There is overreaction to the potential exposure of humans," says J. Davidge Warfield, general manager of the Wilmington, Del., office of Indoor Environmental Technology, a division of Tri-Dim Filter Corp. "Nobody has done a risk assessment of the environment," he adds.
In the case of the 500,000-sq-ft Polk County building, many involved thought the county overreacted and didn't need to do such a major reconstruction. The late 1980s job cost $27 million to build and $37 million to remediate and reconstruct.
Others think there was even more hysteria over the Martin County courthouse. The two-building complex with a leaky exterior insulated finish system (EIFS) on the upper two of four levels cost about $13 million to build in the late 1980s and $26 million to rebuild in the mid-1990s, counting rent for dislocated occupants, legal fees and a built-out fourth floor, according to the county's lawyer.
SPARKS Though mold specialists agree on broad principles regarding mold growth prevention, control and remediation in buildings, experts are still rubbing each other the wrong way over specifics. Sparks fly like colonies of airborne spores over the thresholds of danger to humans, best practices for mold sampling, suitable elimination treatments and techniques, and the level of abatement.
Specifically for mold, there are no federal or local standards for how clean is clean and no regulation of mold remediation contractors. Yet there is an overwhelming body of work on related topics--federal standards for workplace safety, certification of duct cleaners, and hundreds of manuals, guidebooks and the like offering recommended practices for designing and maintaining buildings and their components, with an eye on preventing mold IAQ problems.
In Austin last month, at an IAQ conference, the Indoor Environment Review Board, a nascent group sponsored by a $50,000 grant from the University City Science Center, Philadelphia, met for the first time. The group's goal is to "determine criteria for developing standards to certify mold abatement contractors," says Heinsohn, a board member.
The Cincinnati-based American Conference of Governmental Industrial Hygienists is about to publish Bioaerosols Assessment and Control, a "comprehensive guide" that includes chapters on prevention and control of microbial contamination.
There is much discord and few federal standards because "only recently has building mold growth come to light," says one engineer. Public awareness was elevated several years ago, after 10 infants in Cleveland developed pulmonary hemorrhage and hemosiderosis and one died. A subsequent epidemiological study led by the federal Centers for Disease Control determined a link between the illnesses and exposure in the home to Stachybotrys atra. And an incident in New York City led to a Dept. of Health guideline for mold investigation and remediation, which has become a de facto standard. An update is expected this summer, says the city.
Building-related illnesses associated with mold are not often fatal. They range from fleeting sinusitis headaches and eye, nose and throat irritations that disappear after the victim leaves the building to hypersensitivity pneumenitis, in which the ill person "may never completely recover," says Jarvis. In between is recurring allergic disease, such as asthma.
Many buildings of the 70s and 80s are mold breeding grounds. The Martin County courthouse is the perfect example. It was designed and built when sick-building syndrome was still "in its infancy and the whole thing was still pretty murky," says Michael Evan Jaffe, a lawyer with Arent Fox, Washington, D.C. Jaffe represented the job's construction manager Centex-Rooney Construction Co., Ft. Lauderdale, Fla., during its appeal.
Engineers theorize that sealed windows and tighter building envelopes, the norm since the energy crisis a score of years ago, are partly to blame for occurrence and recognition of mold-related sick-building syndrome. Nearly all buildings are are at risk, warns Wojcieszak, though those in hot, humid climates may be subjected to longer susceptibility periods. In a 1991 study of 695 commercial buildings by the Business Council on Indoor Air, fungal growth mold and mildew was present in 35% of the buildings surveyed. Only 4% reported volatile organic compounds.
In building design, a common pitfall that abets mold growth is that architect's fail to factor in the local climate and its impact on the building envelope, especially regarding placement and type of vapor retarders and drainage planes. In the U.S. alone, there are four hydrothermal zones and four rain zones, says Lstiburek. Considering all the types of building envelopes, that adds up to about "100 different permutations" for exterior wall details. Yet, Lstiburek complains, architects are required to comply with a single building code, which doesn't require any differentiation of the exterior wall based on climate.
One glaring example of poor material selection is the use of vinyl wall coverings, considered luxurious and durable, in hot and humid climates. When moisture from outdoors penetrates the exterior wall, the vinyl stops it from being drawn into the building. Mold often grows in the wall, on the vinyl's wet, back surface. "The mildew likes the paste," says engineer Charles C. Cocotas, senior vice president of Tishman Hotel Corp., New York City. Cocotas says Tishman's hotels, which include Disney's Swan and Dolphin in Orlando, still have vinyl wall covering. "We recommend paints that breathe, instead of vinyl, but it's an interior design decision," he explains. To guard against mold problems, Tishman has a preventive maintenance program to check for growth and keep growth in check.
Another common problem in hot, humid climates is oversizing the HVAC system. "When that happens, it isn't able to dehumidify the air," says Lawrence W. Spielvogel, of the King of Prussia, Pa., consulting engineer bearing his name. That causes condensation, providing water for mold growth.
Until recently, most HVAC equipment was not designed to inhibit mold. Currently, "equipment makers are addressing this issue with drainable, cleanable and accessible units," says Luepke. Doubly sloped drain pans, not flat ones, have been available for several years. So have accessible-for-cleaning air handling units. Equipment makers are also using noncorrosive steel, stainless steel or polymer plastic surfaces, which can be cleaned easily.
Thomas J. Kelly, IAQ product manager for Carrier Corp., a Syracuse, N.Y., maker of HVAC systems, adds that double-wall construction, with insulation in the center; insulation with a foil face or insulation with an antimicrobial coating, also discourages mold growth.
NO WAY TO RETROFIT That still leaves a huge installed base. Yet all agree there is no practical way to retrofit a system to discourage mold growth.
Even with a perfect building design, from equipment to envelope, any number of things can go awry during construction to facilitate mold growth. With EIFS, "One of our concerns continues to be the quality of applicators and the ability to adhere to manufacturer specifications and the standards of the EIFS industry manufacturers association," says Bernard Allmayer, spokesman for the Morrow, Ga., based association.
To improve things, EIMA is working with the Association of Wall & Ceiling Industries Association in Falls Church, Va., to encourage certification of wall and ceiling mechanics and inspectors. AWCI is also filming an hour-long training video, due out within the year. Additionally, EIFS with drainage planes have been introduced by all manufacturers, Allmayer says.
EIFS are not the only poorly executed envelopes. One of Spielvogel's most difficult decisions was to recommend replacing the brick facade of the Polk County courthouse, where the liquid vapor barrier had been misapplied. "It cost an excess of $5 million," Spielvogel says. In the process, other construction flaws were uncovered, which justified the decision, he adds.
Construction mistakes can easily be covered up, only to rear their heads later in the form of mold growth. Consider this common scenario The contractor, in a rush to avoid late penalties, installs mold-friendly gypsum board before the building is enclosed. It rains, the board gets wet and doesn't dry before it is painted. Down the line there is a mold problem. Another scenario A contractor stores gypsum board, fiberglass insulation or any porous material on site. It gets rained on and is installed that way and covered up. Down the line there is a mold problem.
Despite this, Wojcieszak tends to let the contractor off the hook. "In most cases, contractors will build it the way it is drawn or specified," he says, but "there are a lot of buildings designed to fail." Of the buildings he mitigates, he tracks 30% of the mold problems to a faulty envelope, 33% to faulty engineering, 33% to faulty operations and the rest to poor maintenance.
Lstiburek faults architects the most, because they are charged with "coordinating the design team yet they are not trained in the physics and materials of building design." That leaves no leader who understands how all the pieces fit together, he says. But Lstiburek also attacks engineers, who have "become specialists and have no idea how their systems interact with the envelope, or with each other."
In open-air plenums, for example, condensation can drip onto ceiling tiles--a favorite fungal food. Even concrete will support mold growth, if a nutrient is present. Dirt will do.
Blaming only designers is a gross oversimplification, counter others. W. Wade Selliff, president of the Lakeland, Fla., firm that bears his name and the architect for the Polk County courthouse, points the gun back on the contractor "Unfortunately, there are a bunch of brokers out there who primarily go after the lowest price."
In Polk County, the county actually recovered a total of $45 million from the contractor and its insurer. The architect did not contribute a cent, says Selliff.
At the Martin County courthouse, the county recovered most, but not all, of the monies from the contractor and its insurers. There were $3 million in settlements with the now-defunct architect and its insurers, and a total of $24 million from lawsuits against Centex-Rooney, which held the subcontracts and its insurers.
J. David Odom, a vice president in the Orlando office of CH2M Hill, maintains that "owners go after the cm or contractor whether or not they are responsible because that's where the money is." Designers just don't have as much insurance. Consequently, owners are now beginning to require wrap-up policies, he says.
Selliff says even occupants can contribute to mold proliferation. The court employees initially brought documents into the building "covered with green, brown and black mold," he says. Owner decisions about operations can also abet mold growth, he adds. The HVAC system at Polk County would have worked properly had the county not hired an energy-efficiency consultant to "adjust it," he maintains.
But Barton Malow, admittedly "embarrassed by the project," says Hitz, thinks design contributed to the situation. "Clearly, with respect to the building envelope, in a number of instances, the courthouse was not built in conformance with the plans and specifications," Hitz admits. But the contamination problem had to do with the HVAC system in conjunction with the building envelope. "Every window was operable, anyone could open one," providing a clear path in for warm moist air, he says.
As a company, Barton Malow has taken several steps to avoid similar nightmares. It created a group to perform constructibility reviews on the building envelope; it has beefed up training; and it is developing an internal commissioning program. Also, it has put the brakes on growth for its own sake, says Hitz, explaining that the firm was overextended during that project.
Selliff, though exonerated, learned a lesson as well. He now insists the owner hire three clerks of the works to inspect "air conditioning, plumbing and building construction." On the courthouse, there was only one.
Polk County Manager Jimmy W. Keene agrees the county should have had better inspection. "We learned an awful lot," he says.
The Polk and Martin county cases are examples of a popular plaintiff tactic, says Michael K. De Chiara, senior partner in Zetlin & De Chiara, a New York City-based lawyer. "It is very difficult to pinpoint precise problems causing sick building syndrome," he says. "As a result, plaintiffs have adopted a shotgun approach. They blame anybody who had anything to do with design and construction, and then let those people point fingers at each other."
To "retaliate" before the fact, De Chiara recommends partnering. He also suggests recommending commissioning, with peer review of the mechanical system, in writing, and encourages designers recommendations on drawings and in specifications, things like "drying out" the building before its systems are turned on.
But engineers must also consider how their installations interact with others. "The issue, legally, will always come down to foreseeability and what the prudent design professional should have done," says De Chiara. If designers ignore these situations, "they open themselves up to liability," he adds.
For new buildings and old, when occupants complain of sick-building syndrome, owners typically hire IAQ investigators. After inspections, occupant interviews and mold sampling, a report is issued, which often includes remediation specifications.
Sounds simple, but it isn't. Put two mitigators in the same moldy building, and it's likely they will write different specifications. Some believe in using biocides, among them bleach, others don't, claiming that if misused, they are hazardous. Some recommend sanding or scraping affected "structural" wood that cannot be removed, others recommend treating it with a 10% bleach solution. Some even recommend scraping, bleaching and painting.
Sheet metal ductwork, which can be brushed clean, is an easy call compared with mold-contaminated lined ductwork. Many recommend removing the fiberglass liner, which means creating access ports in the sheet metal and wiping the sheet metal with a bleach solution or a commercially available fungicide. Others recommend against fungicide, which may have harmful residual effects. Some call for encapsulating the mold by spraying on a covering. Others don't. The list could go on.
Many look for guidance to New York City's "Guidelines on Assessment and Remediation of Stachybotrys Atra in Indoor Environments," as an unbiased source. It and the bioaerosols book offer recommended levels and methods for abatement, depending on the extent, location and makeup of the moldy material. They explain containment and worker protection.
Companies are starting to recognize there is remediation work available. Asbestos abatement firms, fire and water restoration contractors and certified mechanical system cleaners are being drawn into the field like fungi into a high-efficiency vacuum cleaner. They may be sucking up the cleanup work, say sources, but they are often unprepared, unschooled and irresponsible. Poor-quality remediation is tantamount to opening up a Pandora's box in an affected building. "There are a lot of mavericks out there," says one engineer. "It's like the wild West!"
Alexander J. Hernandez, IAQ technical director for NAC Environmental Services Corp., New York City, says There are federal occupational safety standards, but still, "a lot of remediation contractors just do what they want," exposing workers and building occupants to airborne mold in high concentrations. Heinsohn and others think remediation work should be monitored by qualified, independent firms. "Workers are not that highly trained," she says, and don't understand their vulnerability.
James E. Holland, a certified restorer, who runs the West Coast Training Center for Restoration Consultants, Sacramento, Calif., agrees that mold abaters need certification. He sits on the IERB board.
At Polk County, there was so much mold and so little known. "You had to improvise," says Philip R. Morey, IAQ director at AQS Services, Gettysburg, Pa., and a former consultant to the county. But that was nearly 10 years ago. Since then, says Morey, a biologist-industrial hygienist who is a coauthor of the New York City guidelines and the bioaerosols book, mold prevention and remediation has been "slowly evolving into a little more of a science."
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