Air Sealing And Insulating Exterior Walls In Existing Homes

An area where many homes leak energy is through the exterior walls. Contrary to popular opinion, replacing windows is not the best solution. Air sealing and adding insulation to the exterior walls provides a much greater return on the investment.

There are several reasons existing homes may require additional wall insulation. Often, particularly in older homes, the building wall insulation installed was substandard to today’s technology. Many homes have traditional fiberglass batt insulation in the walls, which can sag over time inside the wall cavity. This leads to leakage with conditioned air escaping and outside air entering the home. In addition, exterior noise intrusion increases. The result is poorer quality of life for occupants and higher monthly energy bills.

Cellulose insulation offers the perfect solution for retrofitting insulation into the walls of older homes. The product can be dense packed by a qualified insulation contractor and the process is very simple. The contractor can complete the project either from the exterior or interior side of the wall. Homeowners tend to prefer the exterior side because it is more convenient and less disruptive. Pictures here show the installation process for both interior and exterior applications.

Once the area is prepped, the contractor drills holes into the wall between each wall cavity. An application hose is inserted through these holes and insulation is blown under pressure, dense packing the product into the cavity. When the contractor cannot add more insulation, they raise the hose a foot at a time and blow more insulation. This process is repeated until the entire cavity is filled. Once completed, the holes are patched and if on the exterior any siding material is reattached.

The walls dense packed with cellulose insulation provide higher R-Value, lower monthly energy bills and improved sound control inside the home. FTI recommends Fiberlite Cellulose Insulation for this application. To learn more about the process, or for assistance finding a qualified local contractor, contact FTI.