How To Identify Old Insulation

From Home Energy magazine:

Identifying Old Insulation

Material	Description	R-Value per Inch*
Fiberglass batts	Pink, yellow, or white; blanketlike	3.0
Loose-fill fiberglass	Pink, yellow, or white loose fibrous material	2.5
Loose-fill rock wool	Denser than fiberglass, "wooly," usually gray with black specks (some newer products are white)	2.8
Loose-fill cellulose	Shredded newspaper, gray, "dusty"	3.4
Vermiculite	Gray or brown granules	2.7
Perlite	White or yellow granules	2.7
Miscellaneous wood products	Sawdust, redwood bark, balsa wood	1.0
Expanded polystyrene board	Rigid plastic foam board (may be labeled)	3.8
Extruded polystyrene board	Rigid plastic foam board (may be labeled)	4.8
Polyisocyanurate board	Rigid plastic foam board (may be labeled)	5.8
Spray polyurethane foam	Plastic foam, uneven surface	5.9
Urea formaldehyde foam+	Whitish gray or yellow, very brittle foam	4.0
Asbestos++	May be mixed with other materials; difficult to identify	1.0

* These R-values are for old insulation only. They take into account settling, as well as average R-values for old materials.
+ Urea formaldehyde foam is no longer sold due to concerns about formaldehyde outgassing.
++ If you suspect that you have asbestos, consult a hazardous material specialist before you disturb the insulation.

Sources: PG&E Stockton Training Center, 1993 ASHRAE Handbook of Fundamentals, DOE Insulation Fact Sheet

http://hes.lbl.gov/hes/makingithappen/no_regrets/insulationold.html