Preventing Mold Problems in Hotels: Mold Remediation
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Megan Headley is the editor of Moldmag
The nonresidential construction market is expected to increase by almost seven percent in 2007, following the growth of near six percent in 2006, according to the American Institute of Architects’ (AIA) semi-annual Consensus Construction Forecast. AIA is predicting the strongest growth—about 13 percent—in hotel construction. “Over the last three years there’s been a huge increase in hotel construction nationwide,” says David
Odom, a principal of Liberty Building Diagnostics Group in Orlando, Fla. “For example, Hilton Hotels is opening an average of one hotel a day during 2007. It’s unbelievable.”
With the rapid construction of such large buildings, one single design flaw could potentially pose a problem—in hotels across the world.
“The process is sort of unique with the hotel industry,” Odom says. “They will come up with a prototype and then they will just replicate that prototype a hundred times and they will do it in very quick periods of time, in a few years. So then the problem with the design of the prototype gets replicated a hundred times.”
Odom adds that he has noticed an increase in the number of “niche” hotels being produced, particularly four and five star hotels. As one example, he cites an impending chain based on the classic Waldorf Astoria in New York. The hotel’s patrons will be expecting the best. If mold appears, it could pose a major problem.
“People are much more concerned about mold odors and mold problems in a $400 a night room than they are in a $40 a night room,” Odom says.
With the potential for increased hotel design and construction, architects and engineers have the opportunity to perfect designs for dry buildings—or the possibility of repeating design problems in chains across the country.
The Hotel Industry Cries Out
Odom says that the hotel industry has plenty of reason to be concerned about potential mold problems.
“If you look back over the last ten years by far some of the largest moisture and mold remediation problems, by cost, have been in hotels,” says Odom. “Without question.” He adds, “There was a real building boom in hotels in the late 1990s and many hotels were having moisture problems and a number went into multimillion dollar moisture problems.”
Bill Garcia, associate principal with TVS Architects in Atlanta, provides oversight of his company’s hospitality projects. Garcia agrees that mold prevention is a focus for the hotel industry.
Garcia says he hasn’t faced any mold problems in a hotel he has helped design. “We’ve been fairly fortunate in what we’ve been doing appears to be working,” he says. Tom Horn, manager of quality control, and Rick Bartels, CEI, manager of quality assurance, quality control and post construction services, both of Perini Building Co., have seen the hotel industry’s concern with water intrusion. They say that for the hotel industry, the preventative cost of eliminating mold and water leakage far outweigh the ramifications of water intrusion after a project is built. Mold equates to a loss of revenue. “There’s a lot of concern in the industry as a whole about mitigating, preventing mold and mildew,” says Garcia. “It’s residential construction and also has a huge assembly component to it, so you’re dealing with a significant number of occupants.” Garcia adds that he hears concern about preventing water intrusion not only from his hotel clients, but also from contractors and project managers involved on those jobs.
Harry M. Neill, CIH, vice president of 1Source Safety and Health Inc. in Exton, Pa., sees what happens when there is a problem somewhere in the design or the construction of an architect’s vision. He says that when he hears concerns about water intrusion prevention, it is from “those companies, architects and engineers, who have been through the problem.”
Designing For A Mold-Free Stay
With the hotel industry coming face to face with mold problems—and the loss of revenue and public relations nightmares that can lead to—designers who focus on hospitality projects are learning some of the key components that can prevent these devastating problems.
“We try to develop wall systems that are appropriate for the climate,” Garcia says. “What’s appropriate in cold climates is not appropriate in hot, humid climates. We get the vapor barrier in the right position, consult with engineers … we typically have a waterproofing consultant in the decision.” Neill agrees that, from his experience, developing an appropriate wall system is a big step toward preventing future water intrusion problems. “[We recommend] on the design side that they look at appropriate vapor barriers and proper pressure relationships in the building,” he says. Horn and Bartels add that the entire exterior can provide reason for concern, with potential for leaks into faulty exterior cladding, roofs and curtainwall. These experts say that anything built below-grade— from parking garages to offices— poses a design risk. Like almost any structure, hotels are subject to problems in the building envelope leading to water intrusion. But there’s another problem that Neill says he often sees occur specifically in hotels.
“Aside from the obvious liquid flow, leaks—which can be flashing or roof issues—one of the major things we see is a hotel or motel being under negative pressure,” he says. Neill explains how negative air pressure created in hotels and motels can lead to mold growth. “If you look at the design of a hotel, you have a lot of bathroom exhausts, you may have a laundry exhaust,” he says. “If the amount of exhaust air is not made up with make-up air, you have a lot of negative pressure.” Essentially, Neill says, this draws hot, humid air in through the wall assemblies. In many hotels, that humid air travels through the wall cavity before it is stopped by an unintentional vapor retarder: vinyl wallpaper. “If you have vinyl wallpaper, that [hot, humid air] gets trapped,”Neill said. The humid air then condenses upon the air-conditioned interior wall and begins to promote the growth of mold. It’s a combination of building envelope and mechanical issues,” Neill says. He adds that it is an issue that can “absolutely” be prevented in the design stage. The experts at Perini note that hotels and resorts have more humid areas within than other structures.
These places can cause problems if not properly ventilated, including bathrooms, saunas, steam rooms, interior swimming pools, kitchens, water features and even planters. Odom agrees that some of these problems can be prevented in the design stage, although he sees envelope problems often stemming from construction issues. “If I had to oversimplify it … I would say most HVAC problems, most air conditioning, dehumidification problems, are mainly design issues, and most rainwater intrusion issues are construction issues,” Odom says. He cautions, “Now that’s vastly oversimplifying it. But I would say that’s been my impression over the years.”
Finding The Problem—And The Fix
Horn and Bartels note that there is never a time after-hours when hotel management can let in mold remediators without alarming guests. Hotels are always open and run 24 hours a day, seven days a week. In Las Vegas, for example, where properties never close, hotels and resorts simply can’t afford problems relating to mold and water intrusion. In residential and office buildings, investigations into mold problems may often be the result of a health complaint from the occupants.
However, in hotels, the complaints from the transient guests are generally not health-related. “It’s not a concern strictly driven by health,” Odom says. He says concerns are more driven by aesthetic problems. Training maintenance staff to recognize mold problems could help prevent significant problems. When building owners are alerted to the problem and the cause is located, that can be real wake-up call to designers. Neill adds that simple solutions noted in the design stage can mean averting extensive payouts in remediation and reconstruction.
“It seems too simple [to architects] to recommend looking at vapor pressure areas,” says Neill.
“But when these problems occur, particularly behind the vinyl wall covering, it can be extensive.”
Odom recommends that to prevent these design issues, architects consider peer reviewed design processes. Horn and Bartels agree, saying that Perini recommends involving a third party consultant to review design and work closely with the general contractor and owner. The company makes it a practice to hire third-party consultants to check the exterior and all below-grade construction.
Consultants are also hired to test and monitor all interior water features— all planters, sinks, swimming pools, etc., are filled with water and monitored for 24 hours. Kitchens and all plumbing are also tested. Odom offers his advice on what the peer review should address. “I believe the best peer review is one that doesn’t just look at the building envelope and rainwater intrusion, it’s one that looks at the building envelope for rainwater intrusion, vapor diffusion and air infiltration,”
Odom says. “So it’s really looking at the three sources of moisture. It also looks at the second component, which is an HVAC peer review.” He adds that it is still a very underused tool. “There’s no question it’s underused, but there are some barriers to its use,” he says. The first barrier, Odom says, is that in the design phase, architects aren’t expecting a problem.
“I don’t believe in the stage of the project where a peer review would be most likely used, which is in the design stage, anybody is sitting back and anticipating two or three years down the road multimillion dollar moisture problems,” he says. Another barrier he sees is that peer review is not currently common practice. “If I haven’t done it for the last 15 years why do I need to do it now?’” he says. “‘I hired a great designer; I hired a wonderful contractor, we’ve got a good construction manager, why do I really need to have that peer review document?’”
Another problem Odom recognizes is that the process also adds cost to the project. However, he says clients should take the potential costs of repairing a problem into consideration. He says that his company refuses to participate in bids for peer review. Horn and Bartels report that they have heard of some cases of significant losses in the industry that have ended up costing those involved as much to eliminate the mold problem as it did to build the original hotel. “Even if you go to the most expensive peer reviewer, it’s cheap by any standard of what it will save you,” Odom says.
Thermographers Offer Their Advice on Using Infrared
Did your mother ever tell you when you were a kid that you had to eat your carrots so that you’d have good eyesight when you grew up? Urban legends aside, professionals in the mold and moisture industry have been clamoring toward a tool that’s providing an extra strong set of eyes—because these eyes “see” infrared (IR) waves and can pinpoint water damage quickly. “Thermography is the use of an IR measuring instrument, such as an IR camera, to detect and measure the thermal energy emitting from an object,” according to information from Boston-based Flir Systems.
Thermal imaging devices can point professionals in the direction of a moisture intrusion problem by allowing technicians to see the temperature of a surface, as well as areas of dissimilar temperatures that might indicate a problem.
“The great thing about the [IR] camera is that, with the proper training, you can walk in, quickly shoot a building and determine where you have problems with the building envelope—in terms of potential leaks, air gaps and that sort of thing.
It’s not invasive. In other words, you don’t have to tear anything apart.
And, the technology has become easier to use and much more affordable than ever before,” says Larry Wilson, public relations manager with Fluke Corp. of Everett, Wash.
“It allows you to do in a matter of an hour what used to take days to do with a moisture meter,” says Louis Relle, CMRS, co-owner of Relle Thermal Imaging LLC of Gretna, La.
“It is just an excellent tool.”
Seeing Red
These days, most professionals who pick up a thermal imager for the first time know that the gradation of gray or blend of bold color indicates the temperature differences on the surface of the object at which they’re looking. But it’s one thing to look, and another to understand what those subtle shading differences mean. “The first thing people need to do is understand the technology, what it’s going to show them and what it’s not going to show them,” says Wilson.
“When you’re doing thermal imaging you have to establish contrast between one area and another so that you can pick up the differences in temperature,” says Relle.
“You need to find a thermal anomaly,” adds Scott Wood, primary instructor/consultant for the Building Science Institute (BSI) of Fremont, Calif. “its pattern recognition.”
“Because moisture reacts more slowly to a change in temperature than the building material—that can show an anomaly,” says Relle.
“What it [the imager] will do is determine if there are thermal variants Wood notes that as long as evaporation is occurring, there is an approximately 4º Centigrade variation between the water and the nearby building materials. Lew Harriman, cofounder of Moisture Detection and Measurement of Portsmouth, N.H., makes the distinction between indoor investigations and exterior envelope investigations. “That’s just day and night,” he says.
“Indoor water damage problems are extremely simple because, in almost 99.9 percent of the cases, water is evaporating,” says Harriman. “That means the areas that are most moist are darker they’re cooler.”
For exterior investigations, the time of day can make a difference in the investigation.
“Morning and evening tend to work best,” says Relle. That’s because the contrast is greater when the day is beginning to warm up— when water spots remain cool—or the night is cooling off—and moisture is holding onto the day’s heat. “At some point in the day it all tends to blend out,” adds Relle. “You’re not necessarily looking for cool spots, you might be looking for warm spots,” Wilson reminds users. Wilson uses a roof as an example.
“If you run out first thing in the morning to shoot that roof you would be looking for cooler areas because that water has set overnight,” he says. “If you went out after a thermal load in the evening, then you would look for warm spots, because water absorbs heat.”
Supporting Roles If there’s no difference in temperature, there’s no anomaly to find.
Similarly, if a material is completely wet, thermal imaging won’t pick it up, notes John Edgar, CIH, MSPH, MS, CMC, of Relle Thermal Imaging.
Edgar recalls a case he investigated after Hurricane Ivan, in which the hurricane had blown off a building’s decorative roofing. Water had poured under the concrete deck until it was completely saturated.
“We looked at a half dozen roofs, and had no thermal imaging anomalies.
Everything appeared to be the same temperature—and it was,” he says. Using thermal imaging only, investigators were unable to pinpoint the problem because there were no differences in temperature. “When you’re looking at high-rise buildings, if you base the investigation solely on thermal imaging you can make mistakes,” says Edgar.
That’s a key point on which these experts agree: thermal imagers act
as a screening tool that can point an investigator in the right direction— but it has to be backed up with concrete numbers.
“You look for the anomalies and then you go back it up with other moisture meters, etc.,” says Relle. “If we’re going to say absolutely this is wet or this is not, we always back
it up with [another tool].”
“You have to have … more than one moisture meter because you have many things you’re trying to measure,” says Harriman. Edgar adds that when the thermal imager is used in conjunction with a digital camera, the documentation can be invaluable—particularly
if the findings are called into the courtroom.
“If you see something that’s on the side of a building or on a wall, you can take that picture. Then you go back and verify with a moisture meter, and take a digital picture,” says Edgar.
Harriman recalls explaining the use of an IR camera, and the importance of supporting tools, to his colleague David Governo, a partner in Governo Law Firm LLC. Following the explanation, Harriman saw Governo nod in appreciation. “I understand,” he said. “The camera indicts, the meter convicts.” These Waves “Bounce Off Me and Stick On You” These thermographers point out another tricky complication of which new users need to be aware. With some materials, the temperature the thermal imagers show might actually be a reflection from something else. “People using a camera for the first time [must] remember those surface temperature patterns are not just emissions, they’re also reflections from other surfaces,” says Harriman. “If you’re standing next to a window shooting something, you could be getting the reflection,”
says Wilson. “If you’re shooting a mirror and you’re standing in front of it you’ll see the temperature of your body,” elaborates Michelle Relle, co-owner of Relle Thermal Imaging.
“Ceramic floors are a little quirky too,” says Louis Relle. ”They aren’t quite as bad as a mirror, but you have to look at the anomaly out of the grout.” It’s not just the surfaces people typically think of as reflective that can be problems. Surfaces that don’t normally act as a mirror become reflective to IR waves, Harriman explains. A discussion on Identification and Suppression of Thermal Reflections in Infrared Thermal Imaging by M. Vollmer, S. Henke, D. Karstädt, K.-P. Möllmann and F. Pinno of the University of Applied Sciences in Brandenburg, Germany, presented at the 2004 InfraMation conference, discusses this potential problem:
“Thermal reflections are a common source of problems in interpreting infrared thermal images. In particular, atomically smooth surfaces like glass, metals, or wet surfaces, and also brick and concrete, may easily give rise to reflections of infrared radiation from often uncared sources. If unnoticed, these thermal reflections may give rise to misinterpretations of the object temperature.”
The writers further observe that objects can be “a poor mirror in the visible, but a good mirror in the infrared. This behavior is due to the relation of surface roughness versus wavelength of the radiation.” “There are a lot of little subtle things that will affect what the thermographer
is viewing on the camera,” says Wood.
Edgar advises that, “The thermal image is not what determines what’s going on, it’s really the expertise of the investigator.” Building that expertise takes training and plenty of practice.
Taking Off the X-Ray Vision Glasses While thermal imagers can be powerful tools, there are some misconceptions among new users about what this tool can accomplish.
“People have to keep in mind …that IR cameras show surface temperature patterns and they show nothing else. If you forget that—and it’s so easy to forget because it kind of doesn’t look like that—then you get distracted into, ‘Gee I want a better camera that will see deeper into the wall,’” says Harriman. “They think it is an x-ray, and it’s actually seeing into the wall cavity,” says Louis Relle. “Really, you are truly just measuring the surface temperature. That is an absolute misconception that people have.” “Most building materials are not IR windows, and you’re only looking at surface temperatures,” adds Wood. Louis Relle recalled a training exercise done at a hotel. His staff was walking through the hotel with the IR cameras, searching for evidence of moisture intrusion—until hotel management began to complain.
“They had people freaking out, asking, ‘Are they looking through the walls into my hotel rooms?’” says Louis Relle. Wood adds another misconception— he says that his truly ‘green’ students expect their camera to do all the work. “Some of them want to know what button to push to tell where the water is. It’s not a single button— you can’t just turn it on autopilot. You have to tune the image,” says Wood.
So Who Is Riding the IR Wave?
Thermal imagers have definitely become the “in” tool for the mold industry. Rarely does a trade show go by without a seminar on the topic—no matter what the show, because it’s a tool that spans a number of industries and numerous applications.
“Thermal imaging goes across all markets—it can be used for electrical work, water damage, building diagnostics, etc.,” says Wilson. “It’s a fairly broad market.”
Wood sees individuals with a broad variety of backgrounds attending his training sessions at BSI. He sees professionals “from the restoration firm with a minimal amount of technology, but who want to document moisture,” ranging to the “high-end building investigators who are looking for construction defects, building design problems, flashing issues and where they’re using the tool as an additional view of the building.” He also sees some degree of crossover in the fields for which his students use thermography. “You have people who have 20 or 30 years of thermography experience… but they don’t know anything on building sciences,” says Wood.“I end up talking to two types of customers: water damage restoration people and building investigators,” says Harriman. “I make a distinction between those two even though there’s a lot of overlap.”
He explains that the type of thermal imagers these customers need vary greatly.
Water damage professionals, he explains, are generally looking to get “the biggest bang for the buck” because they may be investing in more than one IR camera.
“Water damage people really need few features,” Harriman says. “They need something that’s really tough and has a lot of battery life.” He adds that in the last three years, he’s seen an increase in the number of water damage professionals investing in IR technology. Building investigators, Harriman finds, are dealing with more complex problems than the water damage professionals, and “tend to want the most complex camera possible.” He says that while these investigators generally do need the highest resolution available, no one should purchase an IR camera that’s overly complex, especially if they won’t be using the tool on a daily basis.
One thing the pros agree on is that the number of possible applications is increasing.
The Right Tool for the Job
As thermography grows in popularity in the moisture management- related industries, the number and types of tools available has grown as well. These professionals recommend looking for a durable, rugged tool with a simple user interface. “You want to have enough capability in the camera that it gets you what you need without having so many bells and whistles that you can’t figure out how to use it,” says Wilson. “A lot of people in this market have told me they’ve gotten rid of cameras that are too complex to use,” says Harriman.
Quality is also important to these professionals. “The low-end models I have almost no experience with,” says Louis Relle. “We’ve heard complaints about the clarity of less expensive models.”
Harriman notes that potential customers can find cameras for less than $7,000, but he recommends investing $7,000 to $20,000 for a reliable tool with high resolution. “$7,000 and up, pretty much any camera will work,” says Harriman. “It becomes more a question of balancing the price for the features.” He adds, “Everyone needs the best possible image they can get.”
Harriman says he has also found that most water damage professionals “don’t like color because it confuses the image.”Louis Relle has found some accessories to be useful.” We have additional lenses for our units so that you can zoom in or look at things from a further distance,”he says. Edgar elaborates, “When you’re looking at a 15-story building with thermal imaging, you can actually see those anomalies on the 15thfloor when standing on the ground,” he says.
IR Advice
Wilson advises that anyone interested in purchasing an IR camera do their research first.
“People need to do their homework because there’s a lot of differences. You want to make sure there’s no hidden cost; is software with it or software extra; does it come with training; is it well matched with the purpose you want to use it for?” He stresses that it’s important to know the application for which the camera will be used, so the user can pick a featured capability that matches its use. “My advice to everybody is try to avoid getting confused by superfluous features of cameras and focus on the resolution,” says Harriman. But just as important as research,
Wilson adds, is picking up the tool. “Try it out. Go get it, pick it up, see how easy it is touse, see how it feels in your hand,” advises Wilson. Wood agrees that, in the end, practice makes perfect. “It’s just like driving a car, the more practice you get the better you’re going to get,” says Wood. “You can read the manual; see where to put the key, where the gas pedal is …but to make it a nice, smooth trip it takes a lot of practice.” Once the camera is in hand, these experts remind new thermographers that training is crucial. “On top of that practice, you do really need to understand building sciences and IR thermography. I don’t think it’s a wise idea to pick a camera up, push the buttons and expect to get results thereafter,”
says Wood. “I think that training is essential,” agrees Louis Relle. Wilson notes that there are three recognized levels of IR certification. “There is a 2-day course to become a Level 1 certified thermographer,” he says. “You can get further training. And you should if you get specialized applications,” says Edgar. Levels 2 and 3 offer more in depth thermography training, appropriate for specialized applications or managing thermography programs. Louis Relle adds, “We haven’t really encountered anything in building investigations that wasn’t covered in a Level 1.” Wood summarizes BSI’s basic training session: learning how to “fine-tune” the camera, understanding what you’re actually seeing and why, followed by more indepth information on building sciences. “You really need to know building construction and materials and how they are applied and what your substrates are,” says Louis Relle. Harriman agrees that training in building science gives new thermographers a big edge.“For building investigators who are more experienced with industrial hygiene issues, I would greatly encourage them to go to one of Joe Lstiburek’s and John Straube’s building science symposiums,” says Harriman (for more information on these symposiums, visit (www.buildingscienceseminars.com).
“What they need is to understand the complex layers of an exterior wall … and they need to understand the dynamic hygrothermal behavior of those layers as the sun plays across it during the day.” Harriman adds that investigators coming to thermography with a background in construction defects have an advantage. “Their understanding of those [building] layers is the most important part of thermal imaging. They should understand they have a tremendous advantage over those who do not understand those layers; they should harness that knowledge and think about those layers in a dynamic situation where the sun rises and sets and where the shadows from trees fall on an exterior wall,” says Harriman. “Basically they have a much shorter distance to go for effective and efficient use of a camera.” Harriman has some advice to offer water damage technicians as well.
“The biggest benefit for them is to use their camera … not just for scoping the job but also for managing the job. By that I mean that they can gain a huge benefit by seeing what’s drying now versus what was dry yesterday.” He notes that by using thermal imagers daily, water damage technicians can track damp areas and quickly pinpoint when and where they should redirect their drying efforts. “They’ll speed their drying processes, because they won’t be drying things that don’t need it,” says Harriman.
