Duct board is a semi-rigid fiberglass insulation material often used for residential or light commercial heating and cooling applications in lieu of metal duct. Common characteristics include:

• Dimensions of 4′ x 8′,  4′ x 10′, and 8′ x 10′
• Thicknesses of 1″, 1.5″ or 2″
• R-Values of R4, R6, or R8
• Foil facing
• Black, fiberglass mat facing
• Antimicrobial coating

Advantages of Duct Board

Duct board is manufactured in sheets which are fabricated into the same rectangular shape as traditional sheet metal duct. People might choose it over metal duct because it’s a single product with dual benefits: structural integrity and insulating value. Traditional metal duct systems must be accompanied by a separate form of insulation. This adds to the labor and cost of the overall system.

Duct board insulation is also a quieter alternative to a metal duct because it lacks metal-to-metal contact and metallic components in general. Sound waves can’t travel freely about the system.

Who Makes It?

The primary manufacturers of fiberglass duct board insulation include:

• Certainteed
• Johns Manville
• Knauf Insulation
• Manson Insulation
• Owens Corning

Where Can You Purchase Duct Board?

If you are looking for a sheet or two to repair something in your home or small building, Home Depot is likely your best bet. If you are a contractor looking to purchase it for a larger project, you might search for a distributor in our directory. Larger sheet metal distributors or HVAC distributors often carry this product as well.

How Do You Fabricate and Install?

As with any product, you should be sure to reference the installation instructions from the manufacturer of the product you’re using. Here are some quick links to the ones I could track down online:

• Certainteed: Duct Board Fabrication Instructions
• Johns Manville: The Pocket Installer – Fiber Glass Duct Board Air Handling Systems
• Owens Corning: QuietR® Duct Board Installation Instructions
• Knauf & Manson reference the NAIMA Fibrous Glass Duct Construction Standards & NAIMA Fibrous Glass Residential Duct Construction Standards.

The North American Insulation Manufacturers Association has a great series of 22 videos on YouTube starting with the video below.

Conclusion

For more information about fiber glass duct board, we recommend you reach out to a local distributor or find a manufacturer and visit their website. Also, feel free to add a question to the comment section below because we can put you in touch with someone that can answer your questions.

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