What is Verified R-Value and Why Does it Matter?

Originally published by: Builder OnlineJuly 31, 2019

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The North American Insulation Manufacturers Association (NAIMA) recently rolled out a voluntary program to provide third-party certification that fiberglass and mineral wool batts and rolls comply with FTC labeling requirements for their stated R-value. We asked building science educator Joe Arrigo why it matters.

Fiberglass batts with verified R-value support a cost-effective Grade 1 installation.

The NAIMA Certification program verifies that qualifying insulation products meet their stated R-value. Shouldn’t that go without saying?

Absolutely. You should be able to trust that what’s on the label is in the package. But this kind of verification isn’t possible with all insulation materials. So, for the fiberglass industry to step up and voluntarily submit to third-party testing speaks to a very high level of quality and transparency.

How is that different from other materials?

One of the big challenges with site-manufactured products is the amount of variability. It’s just a lot harder to ensure quality in something that’s being manufactured by different people under different conditions each time. In addition to the knowledge and the precision of the installer, environmental factors like temperature and humidity can also have a big effect on some products. If there’s no way to test the R-value of the product that has actually been delivered, you don’t know for sure what you’re getting. With R-value certification, you do.

How does this affect builders?

Builders are looking for ways to meet tighter energy codes while managing their total cost of construction. So naturally, they want the most dependable results in the least time at the best price. Builders need to weigh all those factors in deciding which thermal and acoustical insulation products to use.

The Insulation Institute published a guide that compares the total cost per home for Grade 1 installation using spray foam, fiberglass batts, cellulose and various combinations. They concluded that using fiberglass batts is a less expensive path to Grade 1, even when accounting for incremental time to get it done.

This is especially effective when you pair the verified R-value of fiberglass batts with a quality-minded installer, such as an Owens Corning Certified Energy Expert.

Why does Grade 1 matter?

Grade 1 helps builders maximize their HERS points, qualify for Energy Star and many utility incentive programs, and obviously it has an impact on heating and cooling performance for the life of the home. Grade 1 is the guide from the manufacturer on how to install their products to get maximum performance.

NAIMA R-value certification for fiberglass and mineral wool batts and rolls reinforces the manufacturer’s in-house testing, so builders, installers and homebuyers have one more layer of confidence that they’re getting the performance they’re paying for.