Denim Insulation

One method of insulation favored by sustainable contractors includes cotton fiber insulation made from blue jean manufacturing cut-offs. A good alternative to fiberglass batts, which are known to be carcinogenic, denim insulation typically has a borate solution added to keep the R.O.U.S.’s (Rodents of Unusual Size- Princess Bride movie, anyone?) at bay and to prevent mold and promote fire resistance. Borate is a natural, non-toxic substance and, though it wards off the beasties, it is safe for humans. In this picture, our West Seattle client chose denim insulation for her kitchen and dining room addition. This is the ceiling and part of west facing wall. Contractors warn that it is a bear to cut, but definately worth the effort.

Another alternative to fiberglass is loose fill cellulose. This is gray finely chopped up newspaper with borate salts typically added. This is a great choice for blowing into attic or closed wall cavities. The presenters at a weatherization gathering last week mentioned they like to apply it wet- which enhances the product even further. Cellulose seems to be the number one pick by the weatherization experts that I work with.