How To Identify Old Insulation
From Home Energy magazine:
Identifying Old Insulation
|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