As a general contractor, if you’ve been contacted to investigate a suspected case of asbestos duct wrap at the site of a business, hospital, school or other organization, the first priority or your investigation will be your own safety. When inspecting the affected area, make sure you are equipped with a simple filtration mask to prevent inhalation of airborne asbestos fibers, should they be present. Asbestos cleanup for contractors can be managed in a safe and proper manner if a step-by-step approach is taken and proven techniques are employed.

Identify the problem

The next step will be to make some kind of identification of the materials in question, either positively or negatively for asbestos. During this inspection, it should be noted exactly where the asbestos materials are in use, e.g. air ducts, chimneys, vibration dampers, etc. The type of asbestos should also be noted so that a precise plan for removal or abatement can later be formulated. Your inspection should include all of the following likely areas of usage:

  • cement asbestos millboard insulation that may be installed either on ceilings or on walls, as a kind of heat shield
  • a white paper-looking material wrapped around heating or cooling ducts
  • a white paste material used as a sealer around some plumbing joints
  • a white insulating materials hanging from pipes in the plumbing system
  • white cement asbestos transite pipe installed as HVAC air ducts, chimneys, or chimney flues
  • white woven material installed as a flexible coupling between heating ducts, or in the vibration damper between the air handler and the duct work

Handle the problem safely

After the full scope of the problem is known, it is always best to contact the appropriate local agency to be sure that all guidelines and regulations are understood, and that full compliance can be observed during removal. There may also be a set of posted guidelines regarding asbestos cleanup for contractors on the local government website. When you and your abatement team are actually on site and ready to perform the removal procedure, here are the steps you should follow:

  • inspect and shutdown the HVAC system so that no airborne contaminants enter it
  • seal off all the supply vents with plastic to prevent cross-contamination
  • install a 3-stage decontamination chamber in accordance with state regulations, and to ensure the protection of all workers involved
  • set some plastic under the ducting to catch any debris that might fall
  • connect a negative air filtration system into the work area
  • once the decontamination chamber is set and work area is under negative air pressure, workers can suit up and begin the removal process
  • to minimize the volume of asbestos fibers released, wet down the duct work before starting the removal process
  • ducting should be removed in sections, and then placed in properly labeled bags
  • all parts of the remaining HVAC system, e.g. boots and plenum, should be stripped of all asbestos and encapsulated, so the ducts can be safely replaced
  • after all removal has been completed, mist the entire area with an encapsulant spray to ensure work area is safe
  • before leaving the work area, a supervisor should inspect it to make sure the full scope of removal work was completed, and that the work quality is acceptable
  • all asbestos material must be properly loaded and hauled away for disposal at the nearest hazardous waste landfill

If these steps are properly followed, asbestos cleanup for contractors can be a safe process for all workers involved, and certainly for the facility which has been freed from the potential health hazards of asbestos.