What Does Asbestos Insulation Look Like? Identification & What to Do

Learn the types and how to tell if it's time to have your insulation tested

Reviewed by Deane BiermeierFact checked by Jillian DaraReviewed by Deane BiermeierFact checked by Jillian Dara

Asbestos-containing insulation commonly found around the home is vermiculite insulation and asbestos pipe insulation.

Asbestos was added to insulation because it was strong and fireproof. The insulation was used for insulating walls, floors, pipes, ductwork, and beams. In the early 1970s, researchers discovered that asbestos-containing materials adversely affected health.

Learn what asbestos insulation looks like, where it might be found around your home, and what to do if you find it.

Why Is Asbestos Insulation Dangerous?

Asbestos insulation is one of the most hazardous materials found in homes. Disturbing and breathing asbestos fibers can cause asbestosis, lung cancer, and mesothelioma.

When moved, removed, disturbed, or damaged, asbestos insulation can become a danger in the home during renovations and repairs. Moving asbestos insulation will cause toxic asbestos fibers to become airborne and potentially inhaled by occupants.

Vermiculite Insulation With Asbestos

Houses built before 1990 may contain vermiculite insulation that contains asbestos.

Most vermiculite insulation containing asbestos in the U.S. was sourced from a mine near Libby, Montana. The raw vermiculite material taken from the mine was contaminated with asbestos. Insulation made from this material represents over 70-percent of the vermiculite insulation found in U.S. homes.

Because the Libby mine closed in 1990, houses built or remodeled before that date might have asbestos-containing insulation. If the house was built after 1990, the chance that your house has asbestos-contaminated insulation is reduced but not eliminated.

What Does Asbestos Insulation Look Like?

Spray-on Insulation

Spray-on insulation can be identified as a thick layer of gray material on the ceiling. This insulation is made up almost entirely of asbestos. When it is disturbed or damaged, asbestos fibers become airborne.

Loose-Fill Insulation

Loose-fill insulation is fluffy and is almost completely made up of asbestos. It was placed on the attic's flooring or blown into a wall's empty spaces.

The types of insulation most commonly made with asbestos are loose-fill, also called blown-in insulation. Loose-fill insulation comes in a variety of materials and is easy to identify by its loose, lumpy form and fluffy or granular texture. Loose-fill insulation does not have a paper backing.

Block Insulation

This type of wall insulation looks like boards and they are made entirely of asbestos. When these asbestos insulation boards or blocks are sawn apart or manipulated in any other way, asbestos is released into the air.

Blanket/Wrapped Pipe Insulation

Pipes in basements, furnace rooms, and utility rooms may be wrapped with asbestos insulation. There are two types: asbestos air-cell insulation and asbestos wool insulation.

• Asbestos air-cell insulation: This insulation looks like corrugated cardboard or paper and is an off-white or gray color. The insulation will be fully wrapped around the pipes, often with an outer casing to hold the insulation on the pipes.

• Asbestos wool insulation: This insulation is fibrous or fluffy and wool-like. Asbestos wool insulation was wrapped around pipes and releases asbestos fibers as this woven type of fabric ages.

Vermiculite Insulation

Vermiculite loose-fill insulation has a pebble-like appearance and typically is grayish-brown or silvery-gold in color. I

It is made from a natural mineral mined from the earth. The mineral expands when heated, creating the lightweight and somewhat stony-looking particles that make up the insulation.

Fast Facts

Since asbestos is fiber-like, allowing it to be woven like fabric, it was once used to make lantern wicks that would never burn up.

Insulation That Likely Does Not Contain Asbestos

Common forms of household insulation typically do not contain asbestos and are considered to be safe: batt or blanket fiberglass insulation, cellulose insulation, loose-fill insulation, and rock wool insulation.

Batt or Blanket Insulation

Batt or blanket insulation comes in long strips about 16 inches wide. A popular brand of fiberglass batt insulation is pink, while other brands are generally white. Batt or blanket insulation is sometimes shredded by hand by the installer to fit wads of the insulation around obstructions.

If your attic or wall insulation is in batt or blanket form, whether it's fiberglass, cellulose, or another material, you generally don't have to be concerned about asbestos.

Warning

If you have vermiculite insulation in your home, you should treat it as though it contains asbestos unless you can confirm through testing that it is safe.

Cellulose Insulation

If you have loose-fill insulation that is gray, soft, and without a shine, it is probably cellulose insulation.

Cellulose contains a high percentage of recycled paper and does not contain minerals. Cellulose looks like shredded gray paper, which looks different than asbestos insulation. Cellulose insulation is a perfectly safe type of insulation that is commonly blown into attics. It also comes in batt and blanket forms.

Loose-Fill Fiberglass

If you have loose-fill insulation that is white and fluffy and has a little shine, it is probably fiberglass fill.

Because fiberglass is a glass product, it has a slight shine when exposed to bright light. It is very soft, almost like cotton candy, and composed of very fine fibers.

Rock Wool Insulation

Often confused with asbestos-containing insulation, another mineral-based loose-fill insulation is rock wool. Rock wool has a fibrous, soft, cottony texture.

Rock wool is usually gray, white, off-white, or brownish-white. It is a manufactured product, made by melting basaltic rock and dolomite with added binders. The raw material is heated to 2,750 degrees Fahrenheit until it melts, then the molten material is spun into fibers with air pressure. Rock wool is installed as loose insulation or as woven insulation batts.

What to Do With Asbestos Insulation Around the Home

If your loose-fill insulation fits the visual cues for vermiculite, the first thing to do is to avoid disturbing it. Asbestos fibers are most dangerous when they are airborne and can be breathed in. Leaving insulation undisturbed greatly reduces the risk of exposure.

You can test the insulation for asbestos using an asbestos testing kit or by having a sample tested at an approved testing laboratory. If you discover that you do have insulation containing asbestos, you can leave it in place or have it removed by a local asbestos abatement company.

For more information on dealing with vermiculite insulation, the U.S. Environmental Protection Agency (EPA) provides a wealth of information about identifying asbestos insulation, safety procedures, and how to remove it.

Frequently Asked Questions

How can I tell if my insulation has asbestos?

Testing by a qualified lab is the definitive way to tell if your insulation has asbestos. Vermiculite loose-fill insulation, a common type of household asbestos insulation, looks like tiny pebbles with a gray-brown or silver-gold color.

How do you identify fiberglass vs. asbestos insulation?

Fiberglass insulation in walls and ceiling looks like long, thick unified strips or mats (called batts). Asbestos insulation generally was not produced in batt form.

Which types of insulation most commonly contain asbestos?

Vermiculite loose-fill insulation found in attics commonly has asbestos. Asbestos air-cell insulation wrapped around pipes looks like corrugated cardboard. Asbestos wool insulation looks like fluffy wool.

Read the original article on The Spruce.