Overhead Insulation Material

Inspected a frame home built in 1916 yesterday. Attic floor was 99% boarded, but some small holes were evident. The insulation “material” under the boards was like nothing I’ve ever seen before. My apologies, but the camera was left downstairs, so no photo. If you could imagine taking school blackboard chalk or calcium, and pulverizing it completely…well, that was the look and consistency of the 4" depth of this “stuff.” Completely homogeneous, white or off-whitish color, and absolutely consistent and powder-like…no fibers or fibrous material evident in the powder, perhaps slightly heavier and denser than talc or talcum powder. I’ve seen all kinds of materials used for overhead insulation, but this was a first. Any theories, or has anyone encountered anything similar in their attic forays??


Just a thought.

Now THAT was funny. Not that I’d know anything about such things, but…that was pretty much the consistency of the material. Whatever it is, it seems fairly inert, but I won’t even hazard a guess as to what its insulating value might be. I’ve seen a few strange things used as insulators, but this one took the cake. I’m going to advise my Client as follows:

“Material composition and specific insulating value of the installed insulation material is unknown, but if you get really bored, c’mon upstairs with a large straw.”


That’s the spirit, Chris!

Attic inspections are hard enough. If you’ve got your humor, you’ve got everything.

Fine or medium expanded perlite perhaps? http://www.perlite.net/

Thanks for the Perlite heads-up, Michael. Never considered it…we run across the coarse version on occasion, but I had no idea it was also available in finer versions. Could be the culprit.