Fiberglass and Mineral Wool insulations are the most commonly used insulation materials in the country.  From appliances to cars to high temperature ovens, most energy conserved is conserved through the use of fibrous insulations.

              POSITIVE FIBERGLASS PROPERTIES:

 1.)  The product is inorganic, it will not rot or support molds.

2.)  The material, especially in batt form, does not settle so insulation ability is not lost over time.

3.)  Fiberglass is naturally noncombustible, no loose chemicals are required to meet fire codes.

4.)  Installed, nothing comparable is lower in cost.

5.)  The product is dry when installed and can be covered immediately.

6.)  Medium density fiberglass has a higher R-Value than most other insulating materials.

7.)  The insulation is installed quickly to facilitate scheduling with other trades.

             DISADVANTAGES OF FIBERGLASS:

1.)  The R-Value is lower than that achieved with foam.

2.)   It must be installed correctly. Sloppy installation will reduce the effective R-Value substantially (up to 40% or more), The fact is that fiberglass is air permeable, wire and other holes through the sole and top plates must be properly sealed before applying fiberglass or the structure will waste heat.  Baffles and blockers must be properly installed in the attic area for the product to perform as expected.  All outlet boxes must be trimmed and insulated behind.

3.) Fixing problems with the insulation is not cost effective after the drywall is installed