Q: I just found out that my 1943 house has insulation in the walls — I’m assuming it’s asbestos. I can’t afford to tear out my walls. What can I do? Are the cancerous fibers getting into the air through large nail holes?
I found out about the insulation when my handyman was installing a drapery rod. After drilling the holes, a little insulation came out on the drill bit and he said, “Do you realize your walls are insulated?” At the moment, I thought it was a good thing, and then later realized it had to be asbestos. I’m so worried about this.
A: First, don’t assume your insulation is asbestos. According to a bulletin put out by the Environmental Protection Agency, houses built between 1930 and 1950 may have asbestos as insulation. But the heyday of asbestos use in construction was from around 1950 to the mid-1970s.
Asbestos is a mineral fiber. It can be identified only with a special type of microscope. There are several types of asbestos fibers. In the past, asbestos was added to a variety of products to strengthen them and to provide heat insulation and fire resistance.
Your wall insulation may be vermiculite, a mineral that may or may not contain asbestos. But even if the insulation contains asbestos, you needn’t worry. It won’t be harmful so long as it stays in the wall. Large nail holes are not enough to create a hazard.
Asbestos is not dangerous unless it is friable — that is, large amounts of asbestos fibers become airborne. We are all exposed to small amounts of asbestos as we go about our daily lives. However, if asbestos is disturbed, larger amounts of asbestos fibers are released, which if inhaled can lead to health problems. Asbestos that might crumble easily if handled, or that has been sawed, scraped, or sanded into a powder, is more likely to create a health hazard.
In general, asbestos material in good condition will not release fibers.
If the material is exposed, such as in old heater-duct insulation, check it regularly for signs of wear or damage such as tears, abrasions — or water damage. Damaged material may release asbestos fibers.
If the asbestos material is in good shape, do nothing.
If it is damaged, the problem can be corrected by either repair or removal.
Repair involves either sealing or covering asbestos material. Sealing (encapsulation) involves treating the material with a sealant that either binds the asbestos fibers together or coats the material so fibers are not released. Pipe, furnace and boiler insulation can sometimes be repaired this way. Covering (enclosure) involves placing something over or around the material that contains asbestos to prevent release of fibers. Walls are such a structure.
But, for you, the bottom line is: Don’t worry unless you are going to make changes that involve taking the plaster or wallboard off the walls. At that point, you should have the insulation tested.
If it does contain asbestos, removal by a professional asbestos abatement contractor is a must. Contact the local office of the California Division of Occupational Safety and Heath for more information about asbestos abatement.
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