Rigid wall board insulation, such as the Kooltherm K12 from Kingspan, is made from a premium performance rigid thermoset fiber–free phenolic insulant, which is a type of exterior foam.
The foam boards are applied continuously over the exterior of a building, beneath the siding or cladding layer. While foam was once solely used on interior wall applications, pioneering builders in the 1980s found that the material was fast and easy to install on the exterior of a home or building as well:
“Once builders understood the building science behind exterior foam,” writes Martin Holladay for Green Building Advisor, “they readily adopted the practice — especially since exterior foam does such a good job of insulating rim joists and partition intersections. Moreover, installing exterior rigid foam is much easier and faster than installing interior rigid foam, because there are far fewer electrical boxes to work around.”
Install rigid wall board insulation right over the studs of the walls to stop thermal transfer through the wood. You can also install wall board over existing solid walls, such as brick or cinder block, to add additional insulation beneath a new exterior.
By adding the wall board at the same time you apply a new exterior facade, you can increase the energy efficiency of the property and its comfort level while lowering labor costs for the project.
You can also use wall board to insulate rim joist and help protect the sheathing from the elements, letting builders create a tight building envelope.