The Dangers of Asbestos Attic Insulation

If you’ve heard of asbestos before, then you probably know that it should be avoided. Exposure to asbestos can lead to the development of primarily two types of cancers, and exposure of as little as a few days has been linked to cancer growth.

While avoiding asbestos exposure should be a top priority for everyone, most attic insulation doesn’t actually contain asbestos. Understanding what asbestos is, what types of insulation contain asbestos, and what to do if you suspect your insulation contains asbestos is important for all homeowners given the potential health risks of exposure.

What is Asbestos?

Asbestos is the name given to a group of minerals that share fire and corrosion-resistant properties. These minerals include:

  • Chrysotile 
  • Amosite
  • Crocidolite
  • Tremolite
  • Anthophyllite
  • Actinolite

Materials containing asbestos inherit its corrosion and fire resistance, which is why they’ve seen use in applications ranging from shipbuilding and repair, construction, and the automotive industry. Examples of products containing asbestos include brake pads, floor tiles and sheeting, cement pipes, vinyl wall coverings, and roofing shingles. 

What are the Health Impacts of Asbestos Exposure?

Even limited exposure to asbestos has been linked to two types of cancer:

  • Cancer of the lung tissue
  • Mesothelioma

Mesothelioma is a type of cancer that affects the lining of the lungs and other organs. It is important to recognize that even very limited exposure to an asbestos material, including asbestos attic insulation, can result in cancer growth years later. This is why it is so critical to avoid any exposure to asbestos containing material, even if you are only exposed briefly.

Does Insulation Contain Asbestos?

Some insulation does. Specifically, some insulation containing the mineral vermiculite may contain asbestos. Vermiculite is a mineral that, when heated to very high temperatures, puffs up. The expanded form of vermiculite has uses in a variety of industries, including organic gardening. 

On its own, vermiculite isn’t harmful. However, between the years 1925 – 1990, a substantial portion of the world’s vermiculite originated from a mine in Libby, Montana. That mine also contained a deposit of asbestos, which contaminated the products that used vermiculite.

One of those products was a type of blown-in attic insulation. So, the easy rule of thumb is: if your attic contains vermiculite insulation, assume it has asbestos in it. While not all vermiculite insulation contains asbestos, much of it does, and the risks of exposure are so great that it is better to err on the side of caution.

To be clear though, other common types of insulation products do not contain asbestos. This includes fiberglass batt and cellulose insulation, both of which are very common in residential homes.

Where Can Asbestos Be Located in Your Home?

Here are some of the most common places where you may find asbestos in your home:

  • HVAC Duct Insulation
  • Ductwork flexible fabric connections
  • Air duct boots
  • Electrical wire insulation
  • Pipe insulation
  • Floor tiles
  • Vermiculite insulation

Vermiculite attic insulation looks like small pebbles that are grey-brown or silver-gold in color. Vermiculite insulation will be installed in between the joists in your attic.

What to do if you Suspect Asbestos Insulation

If you suspect you have asbestos-containing vermiculite insulation in your attic, the most important thing to do is not disturb it. Asbestos poses the most danger when it has been disturbed and enters the air, where the asbestos dust can be breathed into your lungs. 

If you suspect asbestos, leave your attic disturbing as little as possible. Keep in mind these basic rules to help limit exposure:

  • Don’t try to collect a sample of the insulation, touch it, or move it in any way. 
  • Don’t store items in an attic containing vermiculite insulation.
  • Don’t sweep, dust, or clean around vermiculite insulation.
  • Limit access to areas with vermiculite insulation, including for children.
  • Do not attempt to remove vermiculite insulation on your own.
  • Only have your insulation sampled or removed by trained and accredited asbestos professional.

Solutions for asbestos-contaminated insulation vary. Sometimes the best solution is to seal it up in-place since it poses little risk unless it is disturbed. If it has been heavily damaged, it may need to be removed. Removal of asbestos is very tricky, so be sure to not attempt it on your own and consult with the professionals for replacing attic insulation and helping you understand if there is too much insulation in your attic.

Closing Thoughts

Asbestos is the name given to a group of minerals that all share similar properties. Asbestos is only found in insulation made from vermiculite that was mined in Libby, Montana. Though that mine was shut down in 1990, the legacy of the tainted vermiculite it produced persists in a variety of products we may come into contact with.

Even limited periods of exposure to asbestos can lead to the development of lung cancer or mesothelioma. Because of this, if you suspect your attic contains vermiculite insulation do not disturb it. Leave the attic and limit access to it until you can have your insulation professionally tested by a trained and accredited asbestos expert.

Skip the “attic cleaning near me” search and instead give us a call if you have questions about your attic insulation or are concerned about asbestos in your attic, contact us at Attic Construction today!


  1. “Asbestos: Overview”
  2. “Protect Your Family from Asbestos-Contaminated Vermiculite Insulation”
  3. “Vermiculite”


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