Vermiculite is a mineral that is mined all over the world. 


Some vermiculite contains asbestos which is known to have dangerous effects on our lungs.  The major draw to Vermiculite insulation is its unique ability to expand and provide better coverage, and therefore insulation, when heated.


Vermiculite insulation’s primary use was for insulating older homes which had little or no insulation when built.  The brand name Zonolite is what Vermiculite insulation was sold under for two decades from the early sixties until the early eighties.  This particular insulation was sold in large bags at most home improvement stores.  It was highly preferred because of its low price, light weight and ease of installation.  It is estimated today that approximately 15% of the homes in the U.S. contain vermiculite insulation.


Dangers of Vermiculite Insulation

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For 70 years the Libby mine in Montana was the major producer of vermiculite.  In 1990, the mine was closed when it was discovered that the vermiculite being mined there contained between .5% and 8% asbestos with an average of 1-2%.  Asbestos fibers contained in the vermiculite pose dangerous health risks.  When these fibers become airborne they can become lodged in peoples lungs potentially causing serious ailments like asbestosis and mesothelioma to name a few.


It is important to understand that not all vermiculite poses a health risk.  As far as anyone can tell, only vermiculite from the Libby mine contains asbestos. The vermiculite found in the U.S. mines in South Carolina and Virginia is safe.


What to Do if You Have Vermiculite Insulation


If vermiculite insulation is present in your home there are things you can do.  The most important thing is to prevent the asbestos from becoming airborne by enclosing and exposed insulation.  This includes sealing any light fixtures that provide access to the attic insulation.


Some key things to remember when dealing with vermiculite insulation is that a dust mask will not prevent the tiny asbestos particles from entering your lungs.  Also, you shouldn’t store anything in an attic that contains vermiculite insulation and never draw combustion air or ventilation from an attic insulated with vermiculite even if it is encapsulated.  Finally, removal requires a licensed asbestos removal contractor.


A home inspector will note the type of insulation and its coverage etc and offer recommendations accordingly.