Everything You Need to Know About Vermiculite

By Editorial Team

Updated on November 8, 2023

Vermiculite, the insulation that every homeowner who bought a home built before 1990 dreads finding, has made headlines many times for all the wrong reasons.

While its bad reputation is well known, the fact remains that its presence is not always as problematic as one may believe. In order to take stock of this very relevant subject, here’s everything you need to know about it.

All About Vermiculite

Everything You Need to Know About Vermiculite

Source: Canva

Before we go any further, let's start by providing a brief description of vermiculite. As we briefly mentioned in our introduction, this insulation material was used in Canada between 1940 and 1990.

This material was used for the insulation of various elements such as walls, attics, and floors, although to a lesser extent in flooring. Note that it was sometimes placed under mattresses as insulation, so its presence could be difficult to notice at first glance.

Why was vermiculite so widespread at this time? Quite simply because this insulation had a large number of very interesting qualities including a rot-proof and unalterable nature, the ability to offer good thermal and sound insulation as well as high fire resistance and low cost.

As for its appearance, it can vary. Sometimes it’s recognized as having a colour closer to brown or gray, while it’s found to be more similar in hue to gold or silver.

In order to make it an effective insulator, it was once swelled under the effect of heat to a temperature of 1000 degrees. This exposure to intense heat caused air pockets to form inside the particles, hence its insulating properties.

Vermiculite: why is its presence problematic?

The presence of this type of insulation material is considered problematic due to the relatively high probability that it contains asbestos. Indeed, it should be noted that a large proportion of the vermiculite used in Canada comes from an American mine (Libby, Montana). Moreover, about 70% of the vermiculite sold at that time came from this place. The mine in question contained an asbestos deposit, hence the contamination of this vermiculite.

The insulation in question was called "Zonolite® Attic Insulation". Therefore, it’s first and foremost the presence of asbestos inside the insulation material that’s the problem and not the insulation itself.

Can other materials contain asbestos?

Aside from Zonolite brand insulation, asbestos can be found inside other materials:

  • Joint cement for gypsum coverings (between the 1960s and 1985);

  • Insulation for stoves and boilers;

  • Roof coverings;

  • Steam pipes and boilers;

  • Ceiling tiles used for soundproofing;

  • Textured paint;

  • Vinyl floor tiles;

  • Interior wall coverings;

  • Exterior sidings (such as concrete floors and shingles).

Asbestos Exposure: What Are the Dangers? 

Source: Canva

While this topic has already been the subject of another blog post, the dangers posed by asbestos should be reiterated. Indeed, it poses a considerable risk to the health of those exposed to it and can lead to the development of various diseases such as lung cancer, asbestosis (causing respiratory problems) and mesothelioma.

The aforementioned is a lung tumour that can develop in the abdomen or lungs causing dry and persistent cough, as well as chest and shoulder pain.

It’s important to clarify a very important fact about the presence of asbestos in a home: it’s the direct exposure to it that causes a health hazard and not its presence itself. The reason behind this statement is quite simple and boils down to the fact that it’s the inhalation of asbestos particles that’s responsible for the diseases mentioned.

It should be noted that symptoms related to these diseases can take 15 to 40 years to appear and that their severity can vary from one individual to another.

For more information, take a look at our article: Asbestos and lead: take care of your health!

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Does my insulation material contain asbestos?

To find out if the insulation in question contains asbestos, it’s advisable to call on a specialized firm with the expertise required to collect and analyze a sample. Regardless of which firm you’re dealing with, they should collect three samples. Since it’s possible that some of the insulation material will show a lower concentration, it’s better to obtain several samples and not just one.

Note that to be considered positive, a sample must contain more than 0.1%. This method of performing asbestos analysis has been in place since 2004 and obtains the most conclusive result possible. Moreso, new measures have governed the management of waste contaminated with asbestos since 2013 and these have been readjusted over time as new information presents itself.

What to do if you sell your house

Everything You Need to Know About Vermiculite

Source: Canva

This is a question that many homeowners must ask themselves! Of course, the procedure to be followed will depend on the results obtained following the analysis of the samples, which is obviously necessary to confirm or rule out the presence of asbestos inside the vermiculite.

If the results are negative, that's good news! Otherwise, you’ll have two options (which will need to be discussed with the buyer): pay to have the property decontaminated or agree to reduce the selling price of your property. It should be noted that the decontamination work includes an air test at the very end to ensure that there are no asbestos particles in suspension.

Is it a hidden defect?

Continuing on from the previous point, it should be clarified that the presence of Zonolite brand vermiculite is not considered a hidden defect. We should note that the Court of Quebec examined this question in 2009 during a case brought before them.

Its decision is based on a Health Canada advisory specifying that asbestos does not represent a health risk unless one comes in direct contact with it. By the same token, let us remember the importance of having a pre-purchase inspection carried out before finalizing the acquisition of a property.

If you need to do decontamination work, read our article The prices of a decontamination project.

Reduce health risks

Everything You Need to Know About Vermiculite

Source: Canva

First of all, let's start by mentioning that it’s strongly recommended to avoid touching the insulation or moving it. It’s always preferable to hire a firm specializing in asbestos removal projects to avoid being exposed to serious health risks. The safety measures taken by the team responsible for the work and the procedure to be followed will vary depending on the level of risk involved in the project.

Since the insulation in question is usually found in the attic, be sure not to store anything there and make sure no one can enter the area. Also, although it’s less often pointed out, keep in mind that insulation can seep inside walls.

Therefore, it’s a good idea to caulk windows and doors, as well as the space around electrical outlets and along baseboards. In addition, caulking of light fixtures and access to the attic is highly recommended.

Would you like more information about asbestos removal? Read our article All About Asbestos Removal.

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