Wall Insulation Installation Costs
Wall insulation installation costs depend primarily on whether you're insulating during new construction or retrofitting existing walls. For new construction with open wall cavities, spray foam insulation costs $1.50-$3.50 per square foot, fiberglass batts cost $0.50-$1.50, and mineral wool runs $1.00-$2.00 per square foot.
Retrofit installation is typically more expensive because accessing wall cavities requires either removing drywall or drilling injection holes. Injection foam for existing walls costs $2.00-$3.50 per square foot, including the injection process and patching. For a complete home in Franklin, TN, wall insulation typically runs $3,000-$10,000 total.
New Construction vs. Retrofit
The most cost-effective time to install wall insulation is during construction or renovation when wall cavities are exposed. Spray foam can be applied directly to open cavities, providing complete coverage and air sealing in a single application. This approach is both the most effective and most efficient.
For existing homes with finished walls, several retrofit options exist. Injection foam is pumped through small holes drilled in the wall, filling cavities from the inside. Dense-pack cellulose works similarly. Both approaches avoid the cost and disruption of removing drywall, though they may not achieve the same level of air sealing as spray foam on open walls.
Choosing the Right Contractor
Proper installation is critical for wall insulation performance. Poorly installed insulation can leave gaps that act as thermal bridges, significantly reducing effectiveness. Look for contractors with experience in your specific insulation type and positive reviews from local customers.
BST Spray Foam of Franklin has extensive experience with both new construction and retrofit wall insulation throughout Williamson County. Our trained installers use thermal imaging to verify complete coverage and identify any areas that need attention, ensuring your investment delivers maximum performance.