For the roof assembly, Maria’s proposed approach uses closed cell spray foam applied to the underside of the roof deck. When designed as a compliant unvented assembly, this brings the attic inside the conditioned envelope and can help protect ductwork and plumbing located there.
For walls, the options are a flash-and-batt hybrid or a full closed cell cavity fill, depending on cost considerations and the project’s performance target. Both require appropriate thickness, thermal-bridging and vapor-control detailing for the complete assembly.
For ranch buildings, shops and equipment storage, closed cell spray foam applied to metal panels can help limit condensation that otherwise forms on cold surfaces and drips onto machinery. Appropriate protective coatings or thermal barriers must be determined for the building’s use and applicable requirements.
Assembly Design Matters
Roof, wall and metal-building insulation should be specified as complete systems. Foam thickness, moisture control, fire protection and structural requirements must be checked for each project.