Whether or not you should remove half-century-old attic insulation before putting in newer insulation depends on the condition and type of the existing insulation. Here are some factors to consider before making a decision:
Condition of Existing Insulation: Insulation can deteriorate over time due to moisture, pests, settling, and other factors. If the old insulation is damaged, compressed, or showing signs of wear, it may not be as effective as it once was. In such cases, removing the old insulation is usually recommended to ensure the new insulation performs optimally.
Type of Existing Insulation: Identify the type of insulation currently in your attic. Common types from that era include fiberglass batts, cellulose, or mineral wool. If it contains asbestos (common in older homes), it is essential to hire professionals who specialize in asbestos removal and follow all safety regulations.
Energy Efficiency Improvement: If the old insulation is inadequate or has a lower R-value (thermal resistance), removing it allows you to start with a clean slate and install new insulation with higher efficiency to improve your home's energy performance.
Airflow and Moisture Issues: Insulation problems might be linked to airflow issues or inadequate ventilation in the attic. Before adding new insulation, address any ventilation problems to ensure that the new insulation won't suffer from the same issues.
Cost Considerations: Removing old insulation can add extra costs to the insulation installation process. Consider the cost-effectiveness of removing the old insulation compared to leaving it in place and installing new insulation on top.
Potential Contaminants: If the attic insulation has been contaminated by pests or mold, it is crucial to remove it to avoid any health hazards and to prevent the spread of contaminants to the new insulation.
In many cases, it is beneficial to remove old insulation before installing new insulation, especially if it's in poor condition or doesn't meet modern insulation standards. However, this decision should be based on a thorough inspection of the attic, consultation with insulation professionals, and understanding the specific needs of your home. If you're unsure, it's best to seek advice from a qualified insulation contractor who can assess your attic and recommend the most appropriate course of action.