Guidelines from the U.S. Department of Energy’s (DOE’s) Building America program cover the design and construction of wall assemblies that use more than 1 ½ inches of rigid exterior insulation. Written by Joe Lstiburek and Peter Baker of Building Science Corporation (BSC), the 115-page “Measure Guideline: Incorporating Thick Layers of Exterior Rigid Insulation on Walls” offers clear guidance on some of the tricky details required to maintain a consistent “water-control layer” when you have fat layers of exterior foam.
Control layers. Those familiar with Lstiburek’s thinking about building envelopes will recognize the terminology. For Lstiburek, it’s all about “control layers”—the various systems that control the flow of moisture vapor, air, bulk water, and heat through a wall assembly. His is a conceptual way of keeping track of what a wall needs to do. You...
