02/13/2026
A fabulous article on hazardous insulation in some homes.
Vermiculite Insulation
Back in the late 1950’s and through the 60’s, a number of homes were built, or retrofitted with vermiculite insulation. It is no longer in wide use, but if you own an older home, it may be present in the attic or walls.
It is a puffy, loose granular mineral fiber that is light brown and was poured into walls and onto ceilings in the attic. Given the era, you would only see a layer that is 2 or 3 inches thick. It will not usually be accessible in the walls but can be found in the attic fairly easily. If newer insulation has been added in the attic, you may need to move some of it aside to see if vermiculite is present.
Caution: if vermiculite is present, do not disturb it until it has been tested for the presence of asbestos. Some, but not all batches of this insulation, were inadvertently contaminated with asbestos in the preproduction phase. Asbestos can be carcinogenic if fibers are inhaled. The vermiculite should be sampled and tested by a qualified laboratory before disturbing it. Health Canada suggests that its presence is usually harmless if left undisturbed. However, many homeowners, out of an abundance of caution or because they were renovating the attic space, have opted to have it removed by specially qualified contractors.
