What is vermiculite insulation and does a seller have to disclose it because of possible asbestos content?

Vermiculite is a pebble-like loose-fill attic insulation that was commonly installed in Canadian homes for decades. The concern is that a significant portion of the vermiculite sold historically came from a mine later found to contain naturally occurring asbestos, so vermiculite insulation in an older home can, but doesn't always, carry asbestos contamination that isn't visually distinguishable from asbestos-free vermiculite.

Because the material looks the same whether or not it's contaminated, testing by a qualified professional is the only reliable way to know, and most sellers who haven't specifically tested genuinely won't know one way or the other. That limits when a straightforward disclosure duty is triggered, since the duty generally attaches to a seller's actual knowledge of a hazardous condition rather than to the mere presence of an older insulation type. If a seller has had it tested and knows the result, that known finding should be treated like other hidden, health-affecting conditions. Buyers of older homes with attic vermiculite insulation should assume it may require testing before any renovation disturbs it, and factor the possibility of professional removal into their planning rather than assuming it's automatically safe or automatically hazardous.