1. It's their full-time job, not yours. ICAA-member professional insulation contractors devote their time to insulation contracting services and focus on your energy conservation and comfort. A do-it-yourself consumer will find working in a cramped attic to be extremely uncomfortable.

2. Proper installation. Proper installation is essential for insulation to perform properly. Knowledge of vapor retarders, air infiltration, ventilation, recessed lighting, attic baffles to prevent insulation from blocking the airflow from soffit vents, and water pipes are just a few of the areas critical to installation techniques.

3. Access to Knowledge. Professional insulation contractors have access to a wide variety of training, are familiar with local codes and regulations, and can offer guidance about the type and amount of insulation to be used.

4. Proper insurance. Professionals have proper liability insurance.

5. Professional decison making. Professionals can determine which insulation works best added over existing insulation. Professionals can determine vapor retarder requirements and proper placement of vapor retarders.

6. Safety. Professionals are mindful of safety rules while working in areas such as attics where inexperienced do-it-yourselfers can hurt themselves. Professionals know about the hazards of recessed lighting fixtures, electrical wiring (knob and tube hazards), and staying clear of other combustible sources in the attic by using blocking materials properly.

7. Cost. Most professionals purchase insulation materials wholesale -- direct or through distribution, so the total professional job may well be less than what you would pay to buy the materials at retail.