How to Identify Asbestos Insulation in Walls & Attics

by | Jun 30, 2021 | Asbestos | 0 comments

Nowadays, most homeowners are aware of the dangers of asbestos. Unfortunately, before the 1980s, the risks were largely unknown to contractors and the general public. Back then, the material was frequently used, especially for insulation purposes. In fact, asbestos was once considered the gold standard for home insulation, and many homeowners are now paying the price. 


If your home was built in the 20th century, you may be at risk of asbestos exposure. If you have asbestos anywhere in your home, it’s important to identify it. Keep reading to learn more about asbestos insulation, its effects on your health, and how to find and remove it.

What Is Asbestos Insulation?

inspector taking a close look at asbestos in a home

The term “asbestos insulation” can refer to any type of home insulation material that contains asbestos. Asbestos insulation and other asbestos-containing products fell out of popularity in the late 1970s and heavy regulations were put in place by the EPA in 1989. But if you own an older home, the chance that you have some form of asbestos insulation is pretty high. 


Asbestos is a naturally occurring fibrous mineral. The consistency and texture of asbestos make it appear very similar to cotton, and the structure of the fibers is extremely effective at slowing the transfer of heat. That’s why it was considered such a great home insulator for so many years. In fact, insulation products containing between 15% and 100% asbestos can be found in many older homes.

Why Asbestos Insulation Is Dangerous

Inhaling asbestos fibers can have a serious impact on human health and safety. These risks are exacerbated depending on the number of fibers inhaled and the frequency of exposure. That’s why homeowners and contractors who come into contact with asbestos insulation must take precautions.


Asbestos inhalation can lead to a number of unpleasant symptoms, such as coughing, breathing problems, loss of appetite, and chest pain. These symptoms usually don’t occur immediately; rather, they often show up years after exposure. If the problem goes unidentified, long-term health conditions can occur, including the following:

  • Mesothelioma
  • Asbestosis
  • Lung Cancer

Types of Asbestos Insulation

asbestos padding in an oregon home

There are several types of home insulation that can contain asbestos. Unfortunately, it’s not possible to determine whether your insulation material was made with asbestos simply by knowing the type. But some types are more likely than others to pose a risk.


Here are some of the most common types of home insulation which may contain asbestos:

Block Insulation (Foam Board)

Block insulation is made up of rigid panels of material. It’s frequently used to insulate floors, foundations, basement walls, and low roofs and attics. It’s most commonly found in colder climates due to its effectiveness. Unfortunately, prior to the 1970s, these boards were often made of 100% asbestos. It can pose a serious risk when asbestos foam boards are disturbed or demolished, and this should always be handled by professionals.

Loose-Fill Insulation

Easily identified by its fluffy texture, loose-fill insulation is often composed entirely of toxic asbestos fibers and is either poured or blown into place using specialized tubes. This type of insulation is particularly hazardous because it’s easily disturbed by even the slightest movement or gust of air, making it very difficult to avoid inhalation.

Spray-On Insulation

Spray-on insulation is often used in hard-to-reach areas such as wall and ceiling cavities, around pipes and ductwork, and in tight corners. It’s sprayed on in liquid form and then the material expands and hardens to fill gaps. The asbestos content in spray-on products is high and can reach up to 85%. Spray insulation is also dangerous because it’s friable, which means that it’s easily disturbed unless it has been carefully encapsulated.

Blanket Insulation

Blanket insulation comes in either batts (pre-cut sections) or large rolls. It’s very popular in newer construction, used to insulate attics, walls, ceilings, and pipes. Fortunately, blanket insulation is generally made of fiberglass, mineral wool, or a combination of natural and synthetic fibers and is less likely than other types of insulation to contain asbestos. But older materials may still pose a risk, and it’s worth pursuing asbestos insulation testing prior to disturbing blanket insulation.

Vermiculite Insulation

Composed of heat-treated mica flakes, vermiculite insulation is often referred to by its brand name “Zonolite.” It frequently contains asbestos. Mica and certain types of asbestos naturally form under very similar conditions, so they’re often found in the same mining locations and used in the manufacturing of the same products. 


Not only does vermiculite insulation often contain asbestos, but the type of asbestos found in these materials (tremolite or actinolite) is particularly dangerous because it’s known to cause harm at low levels of exposure. Fortunately, vermiculite insulation is easily identifiable. It looks a lot like gravel and usually glitters brown or silvery gold.

Common Places To Find Asbestos Insulation in Your Home

blanket insulation

Many asbestos insulation materials are extremely difficult to recognize visually. That’s why, in order to know for sure if you’re being exposed to asbestos, you need to test for it. 

Asbestos insulation is usually found in less-visible parts of the home, including the following:

Basements and Crawl Spaces

Not all basements and crawl spaces are insulated, but many are. A well-insulated basement can significantly improve the energy efficiency of a home, saving thousands of dollars over time. In unfinished basements, it’s common to see exposed insulation material (not covered by drywall), which may make identifying asbestos easier. But it also poses a greater risk of inhalation.

Walls, Floors, and Ceilings

The structural surfaces of a home are especially important in heat regulation, making them a common location for asbestos products. Asbestos is often embedded in drywall and 

flooring materials and can even be found in popular flooring adhesives such as black mastic.


Although they have fallen out of style in recent years, many older homes have popcorn ceilings, which commonly contain asbestos. While they’re usually composed of less than 10% asbestos, popcorn (or “stucco”) ceilings are extremely friable and can pose a serious risk to human health if disturbed.

Attics and Closets

Attic floors are among the most common places to find exposed insulation material. In older homes, attics are one of the most potentially hazardous areas in terms of asbestos inhalation. When you go up into your attic, you’re likely to be crouching down in the dark and at risk of breathing in loose insulation fibers. If there is exposed insulation in your attic, it’s advisable to wear a mask when you need to access it and have the material professionally tested.

Pipes and Ducts

In the past, asbestos-containing insulation materials were commonly wrapped around pipes and ductwork to protect them from freezing temperatures. These pipe or duct wraps can be entirely composted of asbestos, that’s why it’s absolutely necessary to test for asbestos around HVAC systems.


Finding asbestos in your heating and cooling systems is not only common – it’s also dangerous. This is because disturbance to these materials can easily and quickly travel to other areas of your home through ventilation systems.

How To Identify Asbestos Insulation Safely

According to researchers, there is no safe level of asbestos exposure. Therefore, if you discover insulation in your home that you believe may contain toxic material, you should not try to remove it or inspect it closely by yourself. If you suspect an area may be contaminated with asbestos, you should call a professional, especially if the material is damaged in any way.


This is a good rule of thumb for asbestos insulation. But insulation is not the only place in your home where asbestos could be present. If you find asbestos in your ceiling, in your floor tiles, or anywhere else in your home, it’s important to get a sample tested by a professional lab. For a list of Oregon-approved labs visit  

Types of Asbestos-Free Insulation

asbestos insulation

Some materials like vermiculite insulation almost always contain asbestos, while others rarely do. It’s never safe to make the assumption that your insulation material is free of asbestos without verification. But as a general rule, the following types of home insulation are less likely to contain asbestos:

  • Mineral wool insulation – Rock or slag wool may be used as an insulation material on its own or it can be combined with other materials to make insulation products.
  • Fiberglass insulation – Fiberglass insulation can be loose or in blanket form and offers excellent energy control, fire resistance, and noise reduction. 
  • Cellulose insulation – Made of finely shredded recycled paper, cellulose is a highly fire-resistant insulation material that rarely contains any toxic fibers.

What To Do if Your Insulation Contains Asbestos

If you suspect that the insulation or other building materials in your home might contain asbestos and would like more information about safe maintenance and removal, you can find it on the Oregon accredited asbestos laboratories list.  


JSE Labs has a team of highly trained professionals to test materials in your home for asbestos so that you can ensure the health and safety of your family. You can drop off or mail your sample (make sure you wear gloves and take safety precautions) or contact us to schedule an in-home visit to have our experts collect and inspect your sample for you.


how to check for mold, asbestos, and lead checklist



Lisa Jones-Stohosky

Lisa Jones-Stohosky

Lisa started in the industrial hygiene and environmental industry in 1992 as an asbestos microscopist and began performing building inspections for asbestos, lead paint, and other hazards in 1994.

“This career has been an amazing experience, traveling for work to perform inspections both locally and abroad to locations such as Hawaii and Germany. My real love however is being in the laboratory and assisting our wonderful clients.”

Related Posts

What to Do If You Find Asbestos in Your Home

What to Do If You Find Asbestos in Your Home

Owning a home can be an exciting, yet stressful responsibility as many issues may arise that are out of your control and challenging to fix on your own. Some issues are visible to the eye, while others may not be so obvious, such as the air quality of your home....

read more
4 Tips for Property Managers When Encountering Asbestos

4 Tips for Property Managers When Encountering Asbestos

If you manage a residential property or oversee a commercial portfolio, it's essential to know how to handle asbestos encounters. Besides project delays, a poorly managed asbestos-related incident can create significant health and safety risks for a building and its...

read more
How to Properly Test for Asbestos: Tips and Risks to Know

How to Properly Test for Asbestos: Tips and Risks to Know

Most people know enough about asbestos to know it’s not something you want to find in your home or commercial building. But if you’ve never dealt with asbestos on your property or worked in a field like construction or public health, you may not be aware of how common...

read more