Tech Talk: Rigid Foam Insultation

Today we would like to present to you a little ‘tech talk’. Now, those familiar with our industry buzzwords will understand the topics of rigid foam insulation and wall assembles. If those terms are unfamiliar, let us help you gain a better understanding before continuing.

                In our world (both EPS and every day), rigid foam insulation is included in more construction projects than one would expect. Recognized as a building material, rigid foam insulation panels are designed to provide thermal resistance to building’s walls, foundations and roofs; often denser and thinner than other insulation materials.  Rigid foam insulation is placed in a wall assembly; including other components such as wood framing, cladding, control layers (air, thermal, vapor, water) or cement.

                Our particular tech talk today refers to BuildingScience.Com’s final measure guideline: incorporating thick layers of exterior rigid insulation on walls. This report provides the new guidelines released by the U.S. Department of Energy’s (DOE) Building America program; design and construction of wall assemblies exceeding 1.5 inches in thickness. The following outlines the steps to consider when intending to install exterior rigid insulation in thickness exceeding 1.5 inches on the exterior of the wall assemblies:

1.       Identify project goals. Develop project goals with consideration given to climate zone, energy performance, cost, aesthetics and any other project-specific criteria or constraints.

2.       Reviewing building code requirements. Review the locally adopted building code for health and safety, fire and minimum energy performance requirements.

3.       Design. Decide on the wall assembly best suited to the project goals and review the project-specific detailing that will be required to implement the design

            a.       Water control layer exterior of the rigid insulation. The location of the water control later for assemblies has implications for the construction detailing and classing attachment.

            b.      Water control layer behind the rigid insulation. The location of the water control layer for assemblies has implications for the construction detailing and cladding attachment.

4.       Construction. Plan the construction process, including staging and sequencing. For moderate to large projects, consider engaging a qualified contractor to complete the work.

Our efforts for EPS education particularity are focused on the design; thermal control layer. The amount of insulation added to the wall assembly depend on climate zone, building codes and design goals of the project. How much foam is the right amount of foam in wall assemblies? The answer can be found in the detailed report: