Vermiculite insulation contamination photos (C) David Grudzinski Vermiculite Building Insulation Action Recommendations
What to do about Vermiculite Insulation & Zonolite Insulation ZAI in Buildings

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Vermiculite insulation action: what to do about vermiculite insulation in buildings:

What should be done about potential vermiculite-asbestos hazards ascribed to Zonolite ZAI attic insulation? Should the vermiculite insulation be removed, encapsulated, sealed, or left alone?

This article series explains ow to recognize vermiculite building insulation that may contain asbestos fibers. 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.

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What to Do About Zonolite or Other Vermiculite Building Insulation

Vermiculite insulation still in the original bag in this attic ceiling may contain asbestos fibers.Article Contents

Health Canada Information on Vermiculite Insulation Hazards in Canada

The following advice is adapted & excerpted from Health Canada's vermiculite risk minimization advice, cited below. Note that the advice presumes or pertains to vermiculite insulation that contains amphibole asbestos. That determination can be made only by a laboratory test.

The best way to minimize your risk of amphibole asbestos exposure is to avoid disturbing vermiculite-based insulation in any way. If vermiculite-based insulation is contained and not exposed to the home or interior environment, it poses very little risk. 

Do not use the attic for storage if retrieving items from it may disturb the insulation. If you must go into the attic, walk on boards in order to minimize disturbance of the insulation and use an appropriate respirator mask. Do not remain in the attic any longer than is necessary.

Do not allow children to play in an attic with open areas of vermiculite-based insulation and make sure anyone working in the attic knows about the possible presence of amphibole asbestos.

Common dust masks are not effective against asbestos fibres. [You would need to wear a HEPA filter respirator and you would need to take care not to track potentially hazardous dust into other building areas - Ed.]

If you have vermiculite-based insulation and you decide to have it removed, speak to trained and qualified asbestos removal professionals to handle the insulation removal. They can be found by looking up experts in "asbestos abatement /removal." NEVER attempt to remove the insulation yourself.

If you plan to remodel or renovate--for instance, by re-insulating your attic--in a manner that would disturb the vermiculite, speak to professionals who are trained and qualified to handle asbestos removal before proceeding with the work to be done.

Seal all cracks and holes in the ceilings of the rooms below the insulation (for example, apply caulking around light fixtures and the attic hatch) to prevent insulation sifting through.

If you suspect you have vermiculite-based insulation in your walls, as a precautionary step, seal all cracks and holes. For example, apply caulking around window and door frames, along baseboards and around electrical outlets.

- Health Canada, 26 March 2015, original source:

Thanks to Alan Carson, Carson Dunlop Associates, a Toronto home inspection & inspector education firm for correspondence and refrerences on vermiculite insulation hazards.

US EPA Advice on Vermiculite Insulation

Quoting from the U.S. EPA advice on vermiculite:

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:


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 [image].

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.

Warnings To Consider Before Removing Vermiculite Building Insulation

Watch out: in our opinion, after reviewing the research literature on vermiculite insulation and Zonolite, there are some remaining risks and open questions that consumers should consider when approaching the removal and "remediation" of vermiculite as a hazardous building substance.

It appears that the ZAI claims website information suggests that building owners or tenants may be offered financial relief for the removal of any vermiculite insulation that was or is in buildings within the United States as long as the tenants or owners can provide the documentation required by the claims procedure. [We have asked the claims administrator for clarification on this point.]

That documentation does not require proof that the vermiculite insulation being considered actually was Zonolite nor that it contained asbestos - perhaps because such proof is impossible to establish in many cases such as when the material has already been removed. Therefore it would appear that the claims trust may be burdened by claims to remove vermiculite that did not contain asbestos.

But the total amount of financial assistance available to building tenants or ownes where vermiculite insulation was installed is likely to be a small portion of the total cost of removing loose-fill poured-in vermiculite insulation in a building when that insulation has to be treated as an asbestos-containing material. Such treatment requires costly containment and removal and disposal measures.

In sum, it would make sense to avoid such significant expense if the vermiculite insulation in your building is not harmful.

Photographs & Examples of What NOT to do in a home when you have vermiculite in the attic

Vermiculite insulation contamination photos (C) David Grudzinski - David Grudzinski [4]

Mr. Grudzinski continues with an example of vermiculite insulation that had been missed by previous occupants, owners, buyers of a building.

It appears that some contractors still have no clue how to work around attic insulation, and this home has paid the price. The occupants had no clue and when I arrived and saw what was done, many long faces were observed.

The worst thing you can do when you have Vermiculite in an attic is to allow the bath fan to be blowing the product around.

Vermiculite, depending on its source, (from the Grace mine in Libby Montana) contains tremolite asbestos. For anyone who doesn't’t know the history, serious health and life safety hazards affected mine workers and others exposed to high levels of asbestos dust; millions of dollars in corrections were spent to clean up the site.

The vermiculite insulation product sold under the name Zonolite contained significant levels of asbestos, and was shipped all over the country for use as building insulation, even refrigeration system insulation, and for use in other applications.

Apparently this home owner had no idea of the potential hazard of asbestos dust in his/her home, and allowed this bath fan to blow the vermiculite insulation and its finer dust particles around for years.

Vermiculite insulation contamination photos (C) David GrudzinskiThe attic hatch from which I took the photo, is a pull down stair. Pull-down attic stairs do not provide an air seal between the attic and the occupied space. Further, under some conditions (such as when air conditioning is in use at a building, air (and attic dust) can be drawn downwards from an attic space into the occupied building areas. In my opinion there is a high probability that asbestos may have been released in the living space of this home.

To make matters worse, all sorts of fabric and carpets were tossed in the attic, and as you see in five vermiculite insulation and insulation contamination photos shown here, the vermiculite was disturbed and is on top of the fabric and is scattered everywhere.

To remove the fabric and debris, one will have to disturb the Vermiculite further.

Worse, bringing carpeting (below right) or other items stored in the attic down into the living area means importing vermiculite insulation (reasonably treated as Presumed Asbestos Containing Material or PACM) into the occupied space as well.

Justification for treating any vermiculite building insulation in the U.S. as PACM comes from the U.S. EPA who point out (later in this article) that Zonolite comprised about 70% of vermiculite insulation sold in the U.S.

Vermiculite insulation contamination photos (C) David Grudzinski Vermiculite insulation contamination photos (C) David Grudzinski

Continuing my inspection it was apparent that the air conditioning system air duct (upper center in the photo at above right) passes through the ceiling and down into a closet below. (Second of the next two photos).

Vermiculite insulation contamination photos (C) David Grudzinski

The question arose: how well was that ceiling penetration (above left) sealed against the passage of insulation, air or dust from the attic as it entered the closet (below left)?

I found not a shred of evidence that any measures had ever been taken to contain the vermiculite insulation, and it has spilled into the living space as you can see in our next photograph.

Evidence of Vermiculite & PACM (Asbestos) Entering the Living Space

Vermiculite insulation contamination photos (C) David Grudzinski

Even at the time of my inspection, vermiculite insulation was seen falling out of the closet ceiling and onto closet contents as well as the closet floor (photo at left) because AC duct was installed in this space.

These conditions - vermiculite insulation and dust entering the occupied space of the building have almost certainly been ongoing for decades.

The actual level of airborne vermiculite (and very likely asbestos) dust would have varied as building air movement conditions varied, and would most likely have been highest when fans and/or the central air conditioning system were in operation.

In the attic the A/C system air handler in the attic is sitting in and on vermiculite insulation.

The A/C return air duct was observed to have vermiculite inside.

Vermiculite & asbestos dust contamination in a buildnig (C) & David Grudzinski

This condition virtually guarantees that airborne insulation (and presumably asbestos) dust and fragments would have been drawn into and sent through the air conditioning duct system whenever the air handler blower was operating.

What Should the Building Inspector or Owner Do About Suspected or Known Vermiculite Insulation & Presumed Asbestos Dust Contamination?

Extensive asbestos testing and repairs will be needed in this house.

We [OPINION - InspectApedia] would recommend a professional assessment of the extent of asbestos dust contamination in the building, including settled dust not just airborne dust, and almost certainly professional cleaning of the HVAC system and possibly other building areas are going to be in order.

When a home inspector sees loose vermiculite in a building during an inspection, we recommend not entering such an attic without wearing a HEPA respirator and a TYVEK suit that is bagged and disposed-of (in your home garbage not that at the property) on leaving the attic. If you didn't wear tyvek, dust off outside and wash your clothes. Those steps minimize the risk of importing PACM dust into other areas or buildings.

David Grudzinski, Advantage Home Inspections, is a professional home inspector who contributes on various topics including structural matters. Mr. Grudzinski, Cranston RI serving both Rhode Island and Eastern Connecticut can be reached at 401-935-6547 fax- 401-490-0607 or by email to



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