What is vermiculite?

Vermiculite is a mica-like mineral that was used as insulation in many houses and commercial buildings (sometimes marketed as “zonolite”) between 1920 and the early 1990s. When heated, it expands like “popcorn” into a loose, lightweight material that is absorbent, fireproof, and a good insulator. Much of this vermiculite contained some asbestos when it was originally mined.

If your house is more than 15 years old and insulated with vermiculite, the insulation may contain asbestos.


How do I find out if the vermiculite insulation in my house contains asbestos?

You can have a sample of the insulation collected and sent to a laboratory for testing. You should not do this yourself—have the sample collected by a qualified surveyor or consultant, experienced in conducting
asbestos hazard assessments. Ask to see his or her qualifications before any
samples are collected.

The amount of asbestos in vermiculite is small
(typically 1 to 3 percent) and can be difficult to detect.
Samples should be sent only to laboratories that use
proper testing methods for vermiculite. A qualified
consultant will know which laboratories can accurately
test vermiculite samples.


Insulation containing vermiculiteRemoving vermiculite insulation from residenceZonolite insulation
About Us
Past Projects
More Information