Owens Corning Duration FLEX vs GAF Timberline AS II: Class 4 Shootout for Hail-Prone Minnesota
4min Read
Posted 5.01.2026
The Plymouth homeowner had two Class 4 quotes for her hail-claim reroof. Both contractors swore their preferred Class 4 product was the better choice for hail-prone Minnesota. One was Owens Corning Duration FLEX. The other was GAF Timberline AS II.
Both products carry UL 2218 Class 4 ratings. Both qualify for 10–30% Minnesota insurance discounts. Both are SBS-modified for cold-flex performance. The honest answer: in real-world Minnesota installs, they perform almost identically. The contractor experience matters more than the brand.
I am Noah Bergland, co-owner of Owl Roofing in Shoreview. Below is the head-to-head.
TL;DR
Bottom line: Both products run $7–$10/sq ft installed, lifetime limited warranty, 130 mph wind, UL 2218 Class 4. Duration FLEX uses SureNail technology with a fabric strip in the nailing zone. Timberline AS II uses LayerLock with a wider nailing zone. Both deliver similar real-world Minnesota performance. Pick based on contractor experience and color palette match.
Comparison
| Spec | Duration FLEX | Timberline AS II |
|---|---|---|
| Per sq ft installed | $7–$10 | $7–$10 |
| Class 4 impact | Yes (UL 2218) | Yes (UL 2218) |
| Modifier | SBS | SBS |
| Wind warranty | 130 mph (SureNail) | 130 mph (LayerLock) |
| Limited warranty | Lifetime | Lifetime |
The technology difference
Owens Corning SureNail. Fabric strip embedded in the nailing zone. Resists tear-through and improves wind warranty.
GAF LayerLock. Wider nailing zone with reinforced area. Reduces installer error and improves consistent wind performance.
Both technologies deliver similar real-world Minnesota performance. The differences are marginal in field installs.
“Worked with Noah and it was a great experience.”
— Verified Google review, Twin Cities homeowner
What Owl Roofing Customers Actually Say
Real, verified Google reviews from real customers Owl Roofing maintains a 5.0 Google rating with 30+ five-star reviews.
Noah is the real deal. After our insurance denied our roof claim and the first roofer walked away, Noah showed up the next day and said he thought he could get us a new roof. He delivered. He got us a roof covered by insurance after it had already been declined. We came up with a nickname for him: “The Roof Whisperer.”
— Tyler Moberg, verified Google review
I am an Independent Insurance Agency owner and have worked with Noah on several roof projects. The homeowners have been extremely satisfied with the quality of work and craftsmanship Noah and his crews have provided. From filing the claim to replacing the roof and cleaning up the job site, Noah and his crew are the best!
— Fred Zappa, Independent Insurance Agency Owner
We used Owl Roofing for a repair on our roof in Brooklyn Park, and I was blown away by how good they were. Every member of the team communicated well about the process. Their price transparency was super helpful. They got the work done very fast, and the team was professional and very kind.
— Matt Brown, Brooklyn Park (verified Google review)
Noah and his team are outstanding! His clear communication, professionalism, and workmanship are top-notch. I recommend Owl Roofing to all my clients, friends, and family.
— Christine Westlund, verified Google review
It didn’t feel like dealing with a big company — it felt like working with people who actually care about the homes and community in the North Oaks and Shoreview area. Great people, great communication, and really solid work.
— Cody Warren, verified Google review
Frequently asked questions
Which is better for Minnesota — Duration FLEX or Timberline AS II?
Roughly equivalent. Both SBS-modified, Class 4 impact rated, lifetime warranty, 130 mph wind. Pick based on contractor experience.
How much do these cost in the Twin Cities?
Both run $7–$10/sq ft installed. On a 5,000 sq ft home, $35,000–$50,000 all-in.
Do both qualify for Class 4 insurance discount in MN?
Yes. UL 2218 Class 4 rating qualifies for 10–30% premium discounts.
Where to start
Request a free reroof estimate. For more, see best shingles for MN winters, Class 4 insurance discount guide, and premium exteriors guide.
