Updating the insulation in older homes is critical to making living spaces more comfortable and monthly energy bills more manageable. Unfortunately, most homeowners only think as far as the attic forgetting to consider insulating exterior walls when considering an upgrade.
Depending on the size of the home, their can be as much or more surface area in the exterior walls than the attic. If the wall cavities are not properly insulated (or perhaps not insulated at all which can be the case in very old homes,) the benefit of adding insulation to the attic will be minimized. While more complicated and expensive, it is possible to insulate existing walls. Here’s how the process works.
First, the wall insulation must be evaluated. A home energy audit completed by a qualified Building Performance Institute (BPI) energy auditor provides a complete evaluation of the home. The auditor usually conducts a variety of tests including a blower door test and a thermographic scan. The latter is critical to assessing the insulation in the walls. It utilizes an infrared camera to compare the temperature differences of exterior walls, which will help reveal insulation levels in wall cavities. If the report determines deficiencies, adding insulation to the wall cavities should be considered.
Next, finding an insulation contractor who understands how to update insulation in the walls of a home is essential. A professional insulation contractor can evaluate the exterior walls of the home to determine feasibility of adding insulation. Typically, homes with removable siding are the best candidates for adding insulation to the walls. If it is not practical to go through the exterior side, it is possible to go through the interior side of walls. Although this can create more disruption to homeowners, the process is similar.
Once it is determined that insulation can be added to the walls, here is how the process usually works and which products are most suitable for the job.
Choosing the correct insulation product is important. As noted, it requires a material that can be dense packed via a tube through the holes in the wall. Options are fairly limited to cellulose insulation and foam insulation. In most instances, cellulose insulation is the best product for the job. Here’s why:
Yes, compared to the cost of updating insulation in an attic it is more expensive per square foot to retrofit insulation in walls. But adding attic insulation over rooms where there is insufficient insulation in the walls will only achieve half of the energy efficiency needed. Learn more about retrofitting walls with cellulose insulation and get referrals for qualified contractors from cellulose insulation manufacturers.