In this old house we ran across a lot of vermiculite insulation in the attic.
It is rare in my experience to see this much, seen here in the attic of a 1925 vintage house. Additional fiberglass insulation had been added on top of some of it, and support boards and platforms elsewhere to walk on and store things.
Sometimes called mineral fiber insulation, vermiculite insulation was used in the United States in the early decades of the last century.
It does not burn, which made it very useful as insulation. It is said to have an R-value of 2.08 per inch, which is slightly less than loose-fill fiberglass.
So, what's the problem with it? A lot of vermiculite contains asbestos, although the percentages can vary.
Expert opinions say to assume what you see contains asbestos, which in this form is extremely "friable," meaning particulates can be easily discharged into the air and ingested into the lungs, and therefore it is very dangerous. Vermiculite can cause Asbestosis, Mesothelioma, and lung cancer. And even when ingested in small amounts.
Obviously an environmental remediation company needs to be consulted on how to best proceed here.
How can you minimize the risk when you see it in a house you are purchasing (or living in)?
~ Don't go into the attic space or use it for storage.
~ Make sure the access to the attic is completely sealed.
~ If you decide to remove it, do not try to do so yourself. Consult professionals.
~ Caulk any gaps and holes in the ceiling - light fixtures, cracks in the ceiling, gaps around window or door trim (in case any fell there from the attic).
My recommendation: certainly environmental remediation is needed here. Nobody wants to buy, or live in, a house with known health risks. Vermiculite risk is not an urban legend. It is real and must be taken care of.
Jay Markanich Real Estate Inspections, LLC
Based in Bristow, serving all of Northern Virginia.
Office (703) 330-6388 Cell (703) 585-7560