Thermal bridging: another reason to choose insulated vinyl siding

Thermal bridging: another reason to choose insulated vinyl siding

Does your home have enough insulation in its exterior walls? Depending on your location, you may be pondering that very question while examining your first heating bill of the season. Everyone likes being warm and cozy when outside temperatures drop, but the price for that comfort seems to be increasing every year. You might be surprised to learn that while your walls may have insulation, a home can still lose air you're paying to condition due to a lack of thermal bridging. Below, we explore what thermal bridging is, how it can affect your utility costs, and perhaps even more important, how it can be installed.

Thermal bridging and your home's protective outer envelope

As you may know, your home's protective outer envelope consists of its exterior wall, roof, and basement or crawl space assemblies. The envelope's primary purpose is to keep the air you're paying to condition inside your home and hot or cold exterior air outside where it belongs. How well it performs that function can often be determined by the total "R-value" of each assembly or system.

R-value is a rating assigned to building materials based on their ability to resist the flow of heat through their mass. Put simply, the higher a material's R-value, the better it is at insulating your home. The total R-value of each component of your home's outer envelope is calculated by adding up the R-values of each material that makes up that assembly. A typical exterior wall might have ½ inch Sheetrock as an interior wall finish, fiberglass batt insulation in the wall cavity, intermediate sheathing, and an exterior siding material such as fiber cement, vinyl siding, or brick veneer.

So if your exterior walls consist of these materials, are they already as energy efficient as possible? Do you just need to get used to paying those high heating and cooling bills? Maybe not - you could still be losing valuable conditioned air due to the framing members that make up the structure of your house. If your exterior walls are typical, there's a wood stud every 16 inches and that wood doesn't have anything close to the R-value of the adjacent batt insulation. When added all together, those wood studs could make up close to an entire exterior wall of your home that has very little R-value.

So what's the answer? According to the Vinyl Siding Institute, creating a "thermal bridge of continuous insulation around a home, so heat cannot escape through the studs and framing materials" may solve the problem. Here are two options:

Both of these methods create an insulating barrier across the exterior face of the framing members that acts as a thermal bridge and can make your exterior walls more energy efficient. Using both insulated vinyl siding and an insulation board on the exterior walls can add even more R-value to your home's protective outer envelope.

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