Get matched with top insulation install or upgrade pros in your area

R-value measures how well insulation resists heat flow, which directly affects your home's energy efficiency. The higher the R-value, the better the insulation. By calculating the R-value needed for your specific climate and home design, you can choose the right insulation materials and thickness to keep your home comfortable and reduce heating and cooling costs.

You don't need to remove your old insulation before adding new insulation, as long as it's in good condition. Adding new insulation over existing materials can improve your home's energy efficiency. For example, you can install blown-in insulation around fiberglass batts or place rigid insulation over existing layers to enhance the overall R-value. However, if your current insulation is wet, moldy, or damaged, you should remove it to avoid health risks and maintain optimal performance.

Installing insulation typically takes five to twelve hours for batts or boards, and two to five hours for spray foam or blown-in insulation. The exact time depends on the type of material and your home's layout. If you need to remove old insulation, have a larger home, or hard-to-reach areas, the project may take longer.

The International Association of Certified Home Inspectors has said foam board insulation can last up to 100 years if properly installed. Some insulation materials can suffer from water damage or start to sag over many years, thus reducing their insulating ability. Foam boards shouldn't suffer from sagging but have the potential to get damaged. Any broken pieces of foam board can reduce its insulating effectiveness.