Any material with a relatively high resistance to heat flow can be considered an insulator. See Table A for more details on the various forms and types of insulation. Requires professional installation.
Wet cellulose is used in open walls and attics.
Polyurethane and polyicynene can be used for both finished and open walls, attics and on the undersides of floors. Both seal air leaks and insulate in one step and have a high effective R-value. Fiberglass, mineral wool, cellulose, vermiculite, perlite. Vapor barrier is installed separately. Used for unfinished attic floors.