Photo-Guide to Identifying Vermiculite Building Insulation & Asbestos InspectAPedia® -
How to recognize vermiculite building insulation that may contain asbestos
How to identify vermiculite insulation - photographs of vermiculite particles, sizes, colors
US EPA advice on asbestos-containing vermiculite building insulation
Photographs of asbestos in building products
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How to recognize vermiculite building insulation that may contain asbestos fibers. We include our own as well as US EPA photographs of various forms of vermiculite insulation to assist in recognizing vermiculite in buildings. This document assists building buyers, owners or inspectors who need to identify asbestos materials (or probable-asbestos) in buildings by simple
visual inspection. We provide photographs and descriptive text of asbestos insulation and other asbestos-containing products
to permit identification of definite, probable, or possible asbestos materials in buildings.
While an expert lab test using polarized light microscopy may be needed to identify the specific type of
asbestos fiber, or to identify the presence of asbestos in air or dust samples, many asbestos-containing building products
not only are obvious and easy to recognize, but since there were not other look-alike products that were not asbestos, a visual identification of this material can be virtually a certainty in many cases.
Also see Asbestos HVAC Ducts a field identification guide to
visual detection of asbestos in and on heating and cooling system ducts and flue vents. Also see Micro-Photographs of Dust from the World Trade Center collapse following the
9/11/01 attack. Links to U.S. government and other authoritative research and advice are included.
ASBESTOS FIBER-CONTAINING - Examples of materials that might contain asbestos fibers
Vermiculite insulation is easy to identify by visual inspection, as it is a granular, loose-fill pour-in insulation comprised of particles typically gray or brown or silver-gold in color, often with bits of reflective mica included.
What can be confusing is that vermiculite particle sizes range from about 1/8" in diameter to more than 1/2" in diameter depending on the producer and batch, with a few large particles that can be more than one inch in length.
The individual vermiculite insulation particles, an expanded mineral, are quite light in weight. Depending on the condition of the vermiculite insulation, whether or not it has been disturbed, and also depending on its original manufacture and quality, various amounts of dust and ultra-small particles may also be present.
Vermiculite insulation may be comprised of particles of several colors and shades (see our page top photo), or nearly all of the particles may be consistently the same color, as we show in our closeup photograph of vermiculite (left). This photo shows how we noticed the presence of vermiculite insulation by peering through a crack between attic floorboards. It was not necessary to remove flooring to find this material.
VERMICULITE INSULATION - Vermiculite building insulation may contain asbestos
Our vermiculite insulation photo (left) from the attic of a home in New York state, shows how you might spot the presence of vermiculite insulation even when most of the attic floor has been covered-over. You'll also notice that while most of the vermiculite insulation particles in this photograph are silver-tan or silver gray, some dark fragments are also present, as well as incidental debris.
Protect Your Family from Asbestos-Contaminated Vermiculite Insulation
Vermiculite is a naturally occurring mineral composed of shiny flakes, resembling mica. When heated to a high temperature, flakes of vermiculite expand as much as 8-30 times their original size. The expanded vermiculite is a light-weight, fire-resistant, and odorless material and has been used in numerous products, including insulation for attics and walls.
Sizes of vermiculite products range from very fine particles to large (coarse) pieces nearly an inch long. A mine near Libby, Montana, was the source of over 70 percent of all vermiculite sold in the U.S. from 1919 to 1990. There was also a deposit of asbestos at that mine, so the vermiculite from Libby was contaminated with asbestos. Vermiculite from Libby was used in the majority of vermiculite insulation in the U.S. and was often sold under the brand name Zonolite.
If you have vermiculite insulation in your home, you should assume this material may be contaminated with asbestos and be aware of steps you can take to protect yourself and your family from exposure to asbestos. This Web page provides important information on how to protect yourself and your family if you suspect that you might have vermiculite insulation from Libby, Montana.
Why should I be concerned about asbestos-contaminated vermiculite insulation?
A mine near Libby, Montana was the source of over 70 percent of all vermiculite sold in the U.S. from 1919 to 1990. There was also a deposit of asbestos at that mine, so the vermiculite from Libby was contaminated with asbestos.
Vermiculite from Libby was used in the majority of vermiculite insulation in the U.S. and was often sold under the brand name Zonolite.
If you have vermiculite insulation in your home, you should assume this material may be contaminated with asbestos and be aware of steps you can take to protect yourself and your family from exposure to asbestos.
- original source: http://www.epa.gov/asbestos/pubs/verm.html
Vermiculite Insulation Identification Photographs
Watch out: Depending on the mine from which this mineral-based insulation was obtained, vermiculite insulation may contain asbestos fibers and could present a hazard in buildings, especially
if disturbed during renovations.
The U.S. EPA has photos of the original bags in which this product
was shipped - you're not likely to see these bags in a home, though I've found them on occasion as you'll see in our photo above.
Vermiculite insulation has an R-value of about 2.13 per inch in buildings.
As we discuss at our notes on other loose-fill insulations such as mineral wool or cellulose, any building insulated with loose-fill or spray-in insulation may benefit from the ability of these loose materials to fill gaps and openings more uniformly than might be found if sloppy workers are careless about installing insulating batts.
Drafty insulation installations can cause more heat loss than is made up for by differences in insulation R-values.
Mississippi home inspector Dan Phillips sent along these interesting photographs of vermiculite insulation from a 1940's home in Tennessee.
Phillips added "The home itself was built in the 40’s and had several renovations done to it. The vermiculite was added during one of these renovations in the past, and covered some older insulation as well as serving as single insulation to newer portions of the home." He observed that this particular vermiculite insulation was comprised of a mix of both small reflective mineral fragments (mica-like) as well as larger fragments up to almost 1/4" of expanded vermiculite insulation material.
Without testing by a certified asbestos testing laboratory, we don't know if this particular vermiculite contains asbestos or not, - appropriate warnings were issued to the client.
That experience reminds us that in an older home there are often multiple kinds of insulation present, and they may not all be visible, newer materials having covered older.
Vermiculite Loose Fill Attic Insulation May Go Unrecognized as a Potential Hazard
Home inspector David Grudzinski provides the following vermiculite insulation photographs. Mr. Grudzinski comments:
I write this ... because of the irony in the situation. .... I found some traces of vermiculite in the basement at first in what looked like an area that one would use as a potting shed spot, so I was alert, but not alarmed. I explained what I found to the buyer and his father, and explained that I would be on the look out for other signs of vermiculite in the house.
The attic revealed what I was afraid of. Bags and Bags of the stuff [vermiculite loose fill building insulation produced by W.R. Grace & Co.]. Now I calmly explained the history and concerns to the buyer, then we began to look around and take photos.
What struck me as ironic was that when I started to look deeper, the past occupant must have been in a boiler school program of some kind. there were book about boilers laying on the bags. but then after looking farther, there are actually books about asbestos containment and control sitting right on the bags of Zonolite™ insulation. In the ["Guidance for Controlling Asbestos Materials in buildings" U.S. EPA] book found on the attic floor [right next to this vermiculite insulation] was a picture of the standard corrugated asbestos pipe wrapping you see on a furnace - but this was too funny.
Vermiculite Insulation Identification Images from the US EPA
Web search 08/17/2010, original source: http://www.epa.gov/asbestos/pubs/verm.html#made
What should I do if I have vermiculite insulation?
YOU SHOULD ASSUME THE VERMICULITE CONTAINS ASBESTOS AND DO NOT DISTURB IT! Any disturbance could potentially release asbestos fibers into the air. If you absolutely have to go in your attic and it contains vermiculite insulation, you should limit the number of trips you make and shorten the length of those trips in order to help limit your potential exposure.
We recommend that you:
Leave vermiculite insulation undisturbed in your attic or in your walls.
Do not store boxes or other items in your attic if it contains vermiculite insulation.
Do not allow children to play in an attic with vermiculite insulation.
Do not attempt to remove the vermiculite insulation yourself.
Hire a professional asbestos contractor if you plan to remodel or conduct renovations that would disturb the vermiculite in your attic or walls to make sure the material is safely handled and/or removed.
Our separate websites on Fiberglass building insulation and or series of articles about HVAC duct work defects contain in-depth discussion about possible air quality and health concerns which may be associated with exposure to fiberglass dust.To compare insulating material R-values of fiberglass in various forms as well as other insulating materials, see our Table of Properties of Insulating Materials
Also see these U.S. & Canadian Guides to Asbestos-Hazards in Vermiculite Insulation
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Additional technical contributors & reference sources for this article are listed below.
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Thanks for photographs of transite asbestos heating ducts, courtesy of Thomas Hauswirth, Managing Member of
Beacon Fine Home Inspections, LLC and (in 2007) Vice President, Connecticut Association of Home Inspectors
Ph. 860-526-3355 Fax 860-526-2942 beaconinspections@sbcglobal.net, June 2007
Vermiculite:
Protect Your Family from Asbestos-Contaminated Vermiculite Insulation, U.S. EPA, web search 08/17/2010, original source: http://www.epa.gov/asbestos/pubs/verm.html
Vermiculite Insulation Containing,
Amphibole Asbestos [PDF], Health Canada, September 2009, web search Jan 2011, source: http://www.hc-sc.gc.ca/hl-vs/iyh-vsv/prod/insulation-isolant-eng.php - Quoting from the PDF document:
Some vermiculite insulation may
contain amphibole asbestos fibres. These
products can cause health risks if
disturbed during maintenance,
renovation or demolition. However,
there is currently no evidence of risk to
your health if the insulation is sealed
behind wallboards and floorboards,
isolated in an attic, or otherwise kept
from exposure to the interior
environment.
Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair
Our recommended books about building & mechanical systems design, inspection, problem diagnosis, and repair, and about indoor environment and IAQ testing, diagnosis, and cleanup are at the InspectAPedia Bookstore. Also see our Book Reviews - InspectAPedia.
ASBESTOS IDENTIFICATION IN buildings How to find and recognize asbestos in buildings - visual inspection methods, list of common asbestos-containing materials
Asbestos Identification and Testing References
Asbestos Identification, Walter C.McCrone, McCrone Research Institute, Chicago, IL.1987 ISBN 0-904962-11-3. Dr. McCrone literally "wrote the book" on asbestos identification procedures which formed
the basis for current work by asbestos identification laboratories.
Stanton, .F., et al., National Bureau of Standards Special Publication 506: 143-151
Pott, F., Staub-Reinhalf Luft 38, 486-490 (1978) cited by McCrone
Asbestos NESHAP Adequately Wet Guidance, EPA340/1-90-019, December 1990, U.S. ENVIRONMENTAL PROTECTION AGENCY, Office of Air Quality Planning and Standards, Stationary Source Compliance Division, Washington, DC 20460,original web source: http://www.epa.gov/region04/air/asbestos/awet.htm
Asbestos products and their history and use in various building materials such as asphalt and vinyl flooring includes discussion which draws on Asbestos, Its Industrial Applications, D.V. Rosato, engineering consultant, Newton, MA, Reinhold Publishing, 1959 Library of Congress Catalog Card No.: 59-12535 (out of print, text and images available at InspectAPedia.com).
Fiberglass: Indoor Air Quality Investigations: Health Concerns About Airborne Fiberglass: Fiberglass in Indoor Air from HVAC ducts, and Building Insulation
Enviro-Scare: Electric Power Lines, Electromagnetic Fields, Cancer Risk, & "Enviro-Scare" - The Normal Curve Cycle of Public Fear of Environmental Issues
Dust from the World Trade Center collapse following the 9/11/01 attack: the lower floors of this building contained spray-on fire-proofing asbestos materials.
Asbestos Information Links: Asbestos Detection, Testing, Recognition, Hazards, Field Photos, and Information Sources, including
health-related links such as legal services and information about mesothelioma and other cancers.
Basic Information about Asbestos, US EPA, web search 08/17/2010, original source: http://www.epa.gov/asbestos/pubs/help.html
"Handling Asbestos-Containing roofing material - an update", Carl Good, NRCA Associate Executive Director, Professional Roofing, February 1992, p. 38-43
EPA Guidance for Controlling Asbestos-Containing Materials in buildings, NIAST, National Institute on Abatement Sciences & Technology, [republishing EPA public documents] 1985 ed., Exposure Evaluation Division, Office of Toxic Substances, Office of Pesticides and Toxic Substances, U.S. Environmental Protection Agency, Washington,D.C. 20460
Copy on file as - /hazmat/Asbestos_in_Your_Home_US_EPA.pdf - Asbestos in Your Home - U.S. EPA, Exposure Evaluation Division, Office of Toxic Substances, Office of Pesticides and Toxic Substances, U.S. Environmental Protection Agency, Washington,D.C. 20460