We Value Your Privacy

We and our partners use technology such as cookies on our site to personalise content and ads, provide social media features, and analyse our traffic. Click below to consent to the use of this technology across the web. You can change your mind and change your consent choices at anytime by returning to this site.

Update Consent
Loading ...

How to Tell Rock Wool From Vermiculite

Updated February 21, 2017

While many types of insulation are considered harmless, other types may affect your health. Vermiculite insulation was once commonly installed in homes and is now considered dangerous, since it is often contaminated by cancer-causing asbestos. Another commonly used insulation, rock wool, is thought to be safe. To identify which type of insulation exists in your home, it is important to learn the differences between rock wool and vermiculite.

Loading ...
  1. Observe the texture of the insulation. Vermiculite insulation is loosely packed and granular in appearance, often resembling small pebbles. The size of the pieces may vary from 1/8 inch in diameter to 1/2 inch. Rock wool is made up of soft fibres, rather than loose particles, and has a cottony appearance.

  2. Observe the colour of the insulation. Vermiculite insulation is made up of grey or brown particles that may be sprinkled with bits of reflective gold or silver mica. Rock wool can be either white, off-white or brownish white.

  3. Slip your protective gloves onto your hands. With your gloved hands, feel the texture of the insulation. Vermiculite insulation feels granular between your fingers, almost like small pieces of gravel. In contrast, rock wool feels like dense wool.

  4. Tip

    If you are still unsure of the type of insulation in your home, contact a professional to help you. EPA.gov features photos of vermiculite insulation to help you better identify it in your home. If you find vermiculite insulation in your home, the Environmental Protective Agency advises to leave it alone as opposed to removing it. Covering the insulation with more insulation can be done by the homeowner, but removing it must be done by a professional.


    Asbestos is considered very dangerous to your health. Always take great care when dealing with vermiculite that may be contaminated with asbestos. If you are concerned that the insulation in your home may be vermiculite, do not attempt removal by yourself. Disturbing the insulation could cause asbestos-tainted dust to contaminate your home.

Loading ...

Things You'll Need

  • Disposable gloves

About the Author

Melissa Busse

Melissa Busse is a freelance writer covering a variety of topics, including natural health and beauty, budget balancing and parenting. She received her Bachelor of Fine Arts in studio art from Maryville University in St. Louis.

Loading ...
Loading ...