Vermiculite in the Home
Published July 2007 in The Contractor's Desk
The caller on the other end was near hysterics. “I have vermiculite in my home…am I going to die?” The worst part was that this wasn’t an uncommon call lately. Our offices have been receiving more and more concerned calls dealing with vermiculite since it’s come to light that it contains tremolite, a form of asbestos.
But does it? Truth be told, not all vermiculite material on the market contained tremolite. Before we get too far into the details of how much is in homes, let’s look at what vermiculite is, and how asbestos came to be associated with it.
Vermiculite is a naturally occurring mineral that’s mined from the earth. After the surface material is removed and the ore exposed, holes are drilled, and explosive materials are placed. The miners blast the rock into manageable pieces, which are loaded into trucks and taken to be processed.
What makes this material different from other ores used is that the rock breaks into flake-like pieces, similar to little bits of mica. This material is then blown through a processor and heated. Once heated, trapped water escapes, expanding the material between 8-30 times the original size. This material is now a wonderful insulating material. Not only has it been used for insulation, but also in industrial, commercial, residential, and even horticultural processes. I personally have seen it used in attics, chimneys, gardens (for aeration of the soil), and in cement.