Encasement Bests Removal for Asbestos and Mold

By Beth Leibson

Being North America’s largest asbestos encasement installation, at 4.2 million sq.ft., is a dubious honor. Especially when it involves four mechanical floors plus a two-level mechanical penthouse, amounting to 1.25 million sq.ft. of space.

“We have a lot of structural steel, all coated with between 5% and 10% crysotile asbestos fireproofing,” says Bart DeVries, project manager of Capital Development for Ontario-based Hamilton Health Sciences, a family of five hospitals and a cancer center. The building has full mechanical floors, known as interstitial spaces, located between each occupied floor. All mechanical and electrical services for the building are routed through these spaces into the occupied floors.

Every time Hamilton Health Sciences wanted to undertake a simple project in the mechanical spaces, say making a minor adjustment to the fire alarm, all facilities management employees had to don protective suits and respirators and decontaminate themselves and all tools and materials before leaving the mechanical spaces. The process and downtime almost doubled the trouble and expense of routine maintenance, even changing a light bulb, DeVries explains.

But this situation could not continue. Hamilton Health Sciences faced two major problems: First, the asbestos was falling off the structural steel, creating a health hazard for facilities management and other employees, and decreasing the fireproofing protection. Second, the center planned to undertake a major renovation in the interstitial spaces, a three-year sprinkler installation and fire alarm system update. DeVries estimated that the presence of asbestos would increase labor costs by approximately 30%, bringing a $15 million dollar project up to between $18 million to $20 million. It was time to take action.

Generally, there are three approaches to dealing with asbestos: removal, encapsulation, and encasement.

Hamilton Health looked into the cost of removing all asbestos. But it carried an estimated $150 million price tag, which was prohibitive, particularly for a government-run university and hospital. In addition, the structural steel would have to be re-fireproofed, with no guarantee that the replacement materials were any safer. And encapsulants would add weight to the fireproofing, which might cause problems.

So Hamilton Health decided on encasement.

Asbestos encasement—as well as encasement of lead-based paint—is a two-part process. First, contractors spray on a primer, which coats the surface and prepares it for the sealer, which effectively shrink-wraps the entire surface and keeps the asbestos from flaking off or otherwise affecting occupants. However, neither coating affects the flame-retardant qualities of the original asbestos coating, which is important as asbestos remains the single most effective flame retardant commercially available.

The health center selected products from Environmental Coatings, Inc.(ECI), based in Montclair, New Jersey . The products generate virtually no airborne fibers, have no volatile chemical organisms (VOCs), and are completely harmless. “One of our consultants routinely sprays his salad with our product, then eats it for lunch,” says Joe Cusenza, president of ECI. Products are guaranteed for up to ten years but are expected to last indefinitely within temperature or humidity-controlled environments or indoors.

“We started the encasement program in 2003,” says DeVries, “and we figure we have probably already paid the $8 million investment, just by being able to access our mechanical floors more easily.”

Works for mold, too

This approach also works on mold, though that is a somewhat more complex process, according to Charles Schwartz, owner and principal consultant at Scarsdale, New York-based Environmental Assessment and Solutions Associates.

“Mold rarely appears in a vacuum,” says Schwartz.

“Humidity plus dust produces mold,” says Bruce Jazwinski, manager of Mamaroneck, New York-based Nu-Air Solutions. “Dust is a food source for mold, which can irritate the throat, eyes, and breathing, particularly for people with asthma.”

To solve a mold problem, the company must understand the cause of the mold and address that—be it a leaky pipe, façade, or roof, a need for back-up power, or some other cause.

Next, the contractor must remove all molds from the affected area. Mold is a living material, so it will continue to grow if not removed. Removing mold also involves removing all water-damaged, rotted, and mold-ridden building materials, furniture, sheetrock walls and ceiling, and other materials. The process often involves multiple applications of HEPA (High Efficiency Particulate Air) filters.

Biocides are generally not recommended for this process, says Schwartz, as they are almost as dangerous to humans as the mold they treat. In some circumstances though, such as sewage spillage or backup, they actually are the most appropriate solution.

Once the mold is removed, says Schwartz, encasement with safe products can keep it from growing back, making the process a very useful investment of time and money for most facilities.