During a recent remodeling project that involved adding new rooms, my outdated heating system became a problem. Our noisy, inefficient furnace was on its last legs and the ducts were wrapped with asbestos.
Asbestos is one of those invisible menaces that --at the very least-- is scary. Though the EPA restricted its use as a building material in the 1970s and proposed a 10-year phase-out of products containing asbestos in 1986, many homeowners have old equipment like mine. In my case, state law prevented air-conditioning contractors from modifying the system so the time had come to remove and replace the ductwork.
But what's involved? And is it safe to remove the stuff? Those were the questions on my mind and--no doubt--are on the minds of other homeowners considering this type of project. Here's a step-by-step account of what happened:
Two air-conditioning contractors recommended one asbestos abatement company, so that's the one I called first. This firm gave me a ballpark estimate over the phone, based upon the number of registers in the house: one day at their daily minimum of $1025. For comparison shopping, I called a couple of other firms listed under "Asbestos Removal" in the yellow pages. Their prices were comparable, so I made an appointment for the first company's estimator to come to the house.
The estimator checked the condition of the ducts and measured their lengths. He found a few separations and showed me where the asbestos was a health concern because it was flaking and friable. Following his written confirmation of his phone estimate, we scheduled a removal date.
When the trucks arrived, the workers taped plastic sheeting over all registers and sealed up cracks and openings in the floor (around the kitchen pipes, for example) and sealed the perimeter of the basement crawl space where the ductwork was located. Once the crawl space was reasonably air-tight, they connected a large, clear hose between a vent hole in the exterior wall and a sophisticated vacuum system. When this vacuum was switched on, it created a negative air space under the house that drew all ambient air out through special filters in the vacuum, cleaning the air and preventing tainted air from moving into the house.
* They assembled three plastic-pipe frames, each the size of a small closet, then encased them with polyethylene sheeting. These three chambers, when joined together and sealed at the crawl space doorway, became a kind of "air lock" between the hazardous and safe areas.
* They took air samples from the hazardous area before, during, and after their work. These were taken to a lab; results were made available to us later.
* A trained inspector from the company inspected and approved the workmanship after the crawl space was sealed-off and after ductwork removal.
*Before entering the area, the workers stepped into special, disposable coveralls that bagged even their feet and included a hood. They wrapped duct tape at ankles, collar, and head to tighten the fit, and pulled on disposable respirators.
* Under the house, they first sprayed a water mist to settle any dust. Then they sprayed the entire area with an "encapsulant" that converted the hazardous asbestos fibers into solid, safer form.
They disconnected the ductwork from the register boots and furnace, crushed them, and bagged them in large, doubled poly-bags. Ductwork running up into walls was left in tact (because it was enclosed, it wasn't a hazard) and they painted the boot stubs with a heavy, latex-based coating.
When all removal was complete, they sprayed the entire area again with the encapsulant.
After folding-up and bagging the old ductwork, the workers entered the inner chamber to remove coveralls and gear; they hosed down in the center room; then they dressed in the outer, clean room.
* They tagged and coded the bagged hazardous waste, and gave me a manifest listing the number of bags, to insure proper disposal.
* The next day they had air-quality results ready (asbestos fiber count was below the required standard) and gave me permission to unseal the area.
I may never know whether or not removing the ductwork was even necessary. I do know, however, that when I sell the house someday, the presence of asbestos won't drag down the sales price. And, in the meantime, we can enjoy efficient heating throughout the house and feel confident that the basement area is safe.
--Don Vandervort
www.hometips.com
