Cellulose? Where is this house, humid area?
Never saw this, but looks a little like air-cell pipe insulation. This is considered Presumed Asbestos Containing Material. You should have it tested by an accredited Asbestos Inspector before doing anything to disturb it.
looks like old rock wool batts
It looks like some insulation I encountered on some ducting installed in the 1960s. I had it tested for asbestos and the results came back as just being all cellulose.
It appears to be mineral wool, but it could also be an old Balsam Wool (wood-fiber) batt. Neither would contain asbestos.
All I can say is that if it isn't known and has the appearance of something that could contain asbestos (i.e., not clearly fiberglass or mineral wool, etc), OSHA requires that it be PRESUMED to contain asbestos and treated as such until negated by testing. So if unsure, testing is required if its going to be disturbed.
Expanding on the "humid area" question - do you think the material has gone through numerous wet/dry cycles? Looks like it's turned to dried oatmeal in the pictures
Many thanks to all for suggestions here.
Over at InspectionNews someone else offered the name "Balsam Wool" — and with a little further digging online, that led me to what I now think is the actual answer, an old Kimberly-Clark product called "Kimsul".
Pennsylvania inspector Bill Kibbel, here, describes Kimsul as "layered creped paper," which fits my first impression of the stuff. The photo doesn't convey this very well. And as Ted Kidd says, it's pretty deteriorated at this point.
Kibbel seems certain that Kimsul was manufactured asbestos-free. NY inspector Debra Monte, on the other hand, here seems equally sure of the contrary. So at this point I'm expecting to have to get it tested. — I canned the BD test on my visit date, incidentally, because of this stuff.
looks like old rock wool batts
We had a sample of the insulation lab-tested, and the result was a negative without qualification — no asbestos found. This is only one case, of course. For all I know, some of the product was made with asbestos and some wasn't. But it would seem that it's wrong to say definitively that Kimsul has asbestos in it.
Still wise to wear a dust mask in any attic and around insulation generally, of course.
At least you know now. So many materials contain asbestos its probably more difficult to say it doesn't than it does. Good luck.
We've seen this before on several occasions. It is a cellulosic based product - essentially crenulated or creped paper.
Kimsul Insulation- Seeking new ways to introduce its products for consumer use, Kimberley-Clark created Kimsul, a home insulating product made of creped wadding, impregnated with asphalt. Originally, Kimsul began as insulation paneling for refrigerators. Later, the product appeared in automobiles as dashboard insulation.
Kimsul was promoted as the insulation with many-layer construction; unlike then-typical loose bulk insulation, Kimsul had layers stitched together to form a blanket of uniform thickness.
In connection with a famous 1948 movie, "Mr. Blandings Builds His Dream House," starring Cary Grant and Myrna Loy, Kimsul was advertised as the insulation used in the dream house. The product was easy to install and was resistant to fire, moisture, fungus, vermin and termites. National advertising for the product urged consumers to "Wrap your home in a blanket of Kimsul."
Earlier, Kimsul had been the standard material for insulating Navy quonset huts (prefabricated metal buildings) during World War II. It gave protection against the tropical heat and Alaskan cold.