High-Density Rigid Fiberglass Board

As I am prone to do, I spend hours on the internet perusing looking for new or better products and applications. Basically – how to make a better post frame building, without hurting client’s in their pockets.

Continuous insulation has become an IECC (International Energy Conservation Code) staple, with 2021’s version showing it as an optional portion of wall insulation in Climate Zones 3 and greater. Usually in board form, in post frame construction continuous insulation is best placed on the inside of wall framing, covering all structural members. Continuous insulation reduces energy loss by providing a thermal break and impeding air leakage.

Most common choice for continuous insulation is a foam board – usually (and my choice) expanded polystyrene (EPS), extruded polystyrene (XPS) or polyisocyanurate (PIR), however there are other ways to achieve this objective. One lesser-known (according to article I was reading at certainteed.com), but effective, alternative is high-density rigid foam board.

Interesting – a design solution I knew little about.

CertainTeed offers CertaPro® Board – composed of resin-bonded glass fibers in a range of densities. It can be used to add both thermal insulation and sound absorption to interior spaces. CertaPro® board stiffness ranges from rigid to more flexible for curved and/or sharp-edged applications (granted we do not find many curved applications in post frame construction).

CertaPro® board is available unfaced, or faced with a vapor retardant finish in either clean metallic (FSK) or attractive white (ASJ) surface. CertaPro® boards are easily cut to size and shape and to install. Additionally, unfaced and FSK faced CertaPro® boards are compliant where a fire hazard classification of 25/50 is required, can be used for exposed or non-exposed applications, resist mold and mildew and will not rot or deteriorate.

In applications where walls will dry to interior, unfaced boards should be used. For drying to exterior (higher numbered Climate zones), use products with a vapor retardant finish.

All CertaPro® boards offer a minimum R value of four (4) per inch.