Procedures for Insulating Metal Studs

Insulation Sheath

• The most common method for preventing thermal bridging is to install a continuous thermal barrier around the exterior of your home. This barrier is a structural sheath of plywood or gypsum board that is that is fastened to the metal studs of your home. A layer of rigid foam insulation and house wrap installed over the structural sheath provides a thermal barrier and moisture control.

Spacers

• Thermal bridging is the result of conduction between the steel frame and the outer siding of your home. Installing spacers between the exterior structural sheath and the metal frame of your home will prevent this problem. When installing spacers, use a uniform size and install them on every fastener attaching the exterior structure to the studs. Using spacers made from plastic or another nonconductive material will further reduce the amount of heat loss through your metal studs. This design also creates an air pocket between inside your wall that further increases the insulating capacity of your walls.

Insulating Foam

• Installing self-adhesive, foam tape between your metal studs and the outer layers of your home will also limit the amount of thermal bridging in your walls. Use enough tape to prevent each stud from coming into physical contact with the outer layers of the wall. Sprayed foam insulation or prefabricated foam forms installed on the exterior side of each stud will also prevent thermal bridging and increase the efficiency of your wall. This type of system is designed to completely cover each stud with the gaps between filled using batt or loose-fill insulation.

Considerations

• Properly insulating walls using metal framing requires installation of hardware inside every exterior wall of your home. This type of work is significantly easier and less expensive to do before your walls are finished. If your local building codes do not allow for spacers or insulating foam on metal framing, consider using an alternative type of metal framing. Metal framing that has a smaller surface area connecting it to the exterior sheath will transfer less heat. You can purchase metal studs constructed with dimples or a smaller width that can significantly reduce the amount of thermal bridging in your walls.