Does Spray Foam Shorten Shingle Lifespan? Not According to the Data.

At Koala Insulation of Nashville, we hear it often:
“I’ve heard spray foam will void my roof warranty or ruin my shingles.”

This concern, while understandable, is rooted in outdated information—often circulated by the fiberglass insulation lobby during the rise of spray foam’s popularity. But after decades of field testing and building science advancements, the truth is clear:

👉 Spray foam insulation does not measurably reduce asphalt shingle lifespan.

Let’s dig into why this myth started, what the research says, and what even the biggest fiberglass manufacturers are doing about it now.

🔍 Where Did This Myth Come From?

The idea that spray foam insulation causes shingles to overheat stems from the notion that insulating the roof deck from below traps heat. This was promoted by manufacturers of traditional fiberglass insulation as a way to discourage the growing popularity of spray foam—particularly in hot and humid climates like we have here in Middle Tennessee.

But building science has come a long way. Multiple field studies have examined this very issue across both hot and cold climates.

📚 What the Research Shows

1. Florida Solar Energy Center Report (Parker, 2005)

This study compared vented vs. sealed attics using spray foam insulation. It found that:

• Shingle temperatures over sealed attics were only 5–7°F higher than over vented attics. These tests were done in Florida and Las Vegas, meaning the affect in Brentwood, Nashville, Green Hills, Murfreesboro, Franklin, Columbia, Dickson, Smyrna, Hermitage and Hendersonville should be even less!
• This temperature increase was smaller than the effect of shingle color—black shingles can run 25°F hotterthan white ones.
• The study concluded that ventilation is a far lesser factor in shingle longevity than color or roof orientation.

2. Building Science Corporation / DOE Field Study (Ueno & Lstiburek, 2015)

This extensive field testing compared unvented roofs (with spray foam and fiberglass) to traditionally vented roofs in both Chicago and Houston. Their findings:

• Spray foam roofs had slightly higher sheathing temperatures—but well within safe ranges.
• No premature aging or material failure of asphalt shingles was recorded.
• Moisture control and insulation performance actually improved in spray foam-sealed attics.

🧯 Owens Corning Flips the Script

Perhaps the most telling sign that this debate is settled? Owens Corning—one of the world’s largest fiberglass insulation manufacturers and a vocal opponent of spray foam for years—now owns and distributes their own spray foam insulation products.

Why? Because the science is clear and customer demand is rising. Spray foam is safe, effective, and not a threat to your roof when installed properly.

✅ What This Means for Homeowners in Middle Tennessee

At Koala Insulation of Nashville, we specialize in installing spray foam insulation in attics, crawl spaces, and more—with a deep understanding of proper air sealing and building science.

We serve the entire Middle Tennessee area, including:

• Nashville, Franklin, Brentwood, Nolensville, Mount Juliet, Murfreesboro, Smyrna, Columbia, Hendersonville, LaVergne, Green Hills, Belle Meade, Bellevue, Goodlettsville, Thompson Station, Fairview, Lieper’s Fork and everything in between.

Our consultative approach ensures that if spray foam is right for your home, you’ll know it—and if it’s not, we’ll guide you to the best alternative.

🔗 Want to Learn More?

• Air Sealing Service in Nashville – Koala Insulation
• Spray Foam Insulation Nashville – Koala Insulation
• Unlock Major Savings – Koala Insulation

Still Have Questions?

Call us today at 615-747-2960 to request a free evaluation. We’ll walk you through your options and give you honest, science-backed answers.

Don’t want to pick up the phone? Click here and schedule that evaluation yourself right now: https://book.housecallpro.com/book/Music-City-Insulation-LLC-DBA-Koala-Insulation-of-Nashville/8b2fffc9c7304db4b078844655b75b02?v2=true

Koala Insulation of Nashville — Doing things the right way. No shortcuts. Just solutions that work.