Hail Ratings, Insurance Deductibles, and Where Class 4 Is Required by Code

What is a Class 4 impact-resistant shingle, and do you need one in Colorado? Most homeowners do not realize there are different levels of hail resistance when it comes to shingles. When we talk about impact resistance, we mean how well the shingle resists damage when hail hits it, which depends on the size of the hail and how hard it strikes. On the Colorado Front Range, where hail events happen nearly every single year, that resistance is not a minor detail. It is often the difference between a roof that survives a storm and a roof you have to replace.

This guide covers what the Class 4 rating actually means, a real Front Range hail story where it paid off, why it matters here specifically, how it interacts with today's rising insurance deductibles, and the Colorado cities where Class 4 is required by code.

What a Class 4 Impact-Resistant Shingle Actually Is

There is a rating system for hail impact resistance, and the difference between Class 1 and Class 4 is not a small one. The way I like to think about it practically is that shingles are basically either Class 4 or they are not. Some roofers will talk about Class 3 shingles as a viable option, and Class 4 is a step better than that. But in my experience, when it comes to a practical decision for a homeowner, there is Class 4, the shingles that perform, and then there is everything else.

To make this concrete, compare two shingles commonly used in our area. Our standard shingle, which falls in the "everything else" category, is the GAF Timberline Natural Shadow, a solid architectural shingle that is not Class 4. Our favorite shingle is the GAF ArmorShield II, which is a Class 4 impact-resistant shingle. Class 4 is the highest impact-resistance rating available for asphalt shingles. On the Colorado Front Range, where hail happens nearly every year, ArmorShield II is the shingle we recommend for most homeowners.

A Real Colorado Hail Story Where Class 4 Paid Off

Here is one story out of many that my team and I have from working in Colorado.

In 2023 a really big hail storm came through Erie, Frederick, Firestone, Longmont, and the surrounding areas of the Northern Front Range. We had done hundreds of roofs in that area before the storm, so when it hit, a lot of our previous customers called us back. Those customers had chosen a range of products, some Class 4, some not.

One homeowner had agonized over the decision two or three years earlier. It was a rental house, and she did not want to overspend, but she elected to spend about a $2,000 upgrade to go from a standard asphalt shingle up to the GAF ArmorShield Class 4 roof, because she figured she would be glad she made the investment.

After the 2023 storm, I came out to inspect. From my truck I could already see hail damage on all of her neighbors' roofs. I got up on her roof, did two laps around it, and could not find a single impact that had damaged the shingle. When I got down, she said, "What's the bad news? Give it to me straight." I told her there was no bad news. Her roof held up great.

She was thrilled standing in her driveway. Here is the part that stuck with me. Her insurance deductible was $5,000. Her $2,000 Class 4 upgrade meant she did not have to file a claim, so she was not out that $5,000 deductible. As she put it, only a couple of years after a $2,000 upgrade she had already saved her $5,000 deductible, so she was about $3,000 ahead on the investment. We talk about that openly with homeowners now, because it is exactly the kind of responsible decision Class 4 can be.

Why Class 4 Shingles Matter on the Front Range

There are two main reasons Class 4 matters here.

The first is simple: in some places it is required by code. A number of Colorado building departments now require Class 4 because they have seen the results. We think that is a smart move, especially when it means Class 4 shingles that genuinely perform in our climate.

The second is what the rating actually proves. Class 4 means the shingle has passed the UL 2218 test. In that test, a steel ball is dropped onto the shingle to simulate hail impact. A Class 4 shingle passes it and a standard shingle does not, which means Class 4 is proven to hold up to that impact.

In our experience, the best-performing Class 4 shingles are SBS modified. GAF ArmorShield II is SBS modified, which means there is synthetic rubber mixed into the asphalt of the shingle. That is what gives it the flexibility and durability to absorb a hail strike without cracking. If you want to see this in action, we have a separate video where we drop a steel ball from 20 feet off our building onto these shingles to test them.

Class 4 Shingles, Insurance Discounts, and the Deductible Math

We get a lot of questions from homeowners about Class 4 shingles and insurance discounts: if I install a Class 4 shingle, how much can I save on my homeowner's insurance?

Historically we have seen premium discounts from carriers like Farmers, State Farm, Allstate, and USAA. Keep in mind, though, that especially right now in 2026, we are hearing that a lot of those discounts and incentives are changing. So I actually like to think about the value a different way, by introducing one more variable: the size of your insurance deductible.

When I first started in this industry, deductibles were $250, $500, and a $1,000 deductible was considered big. Now we frequently see $5,000, $6,000, and $8,000 deductibles. In that environment, if a quality Class 4 shingle means you do not have to file a claim the next time hail comes through, you are effectively saving that entire deductible. That is where we have seen homeowners get the best payoff, and it is how Class 4 shingles pay for themselves.

The Colorado Cities Where Class 4 Is Required by Code

Here are the Front Range areas where Class 4 shingles are currently required by building code:

• Fort Collins
• Lafayette
• Loveland
• Unincorporated Boulder County (a more recent addition)

In those areas Class 4 is not optional. If you are replacing an asphalt shingle roof, it has to be Class 4 rated.

Areas where it is currently not required include Denver, Northglenn, Westminster, and Thornton, among others. Many of these may adopt it in the future.

Frequently Asked Questions

What is a Class 4 impact-resistant shingle?

It is a shingle that has passed the UL 2218 impact test, in which a steel ball is dropped onto the shingle to simulate hail. Class 4 is the highest impact-resistance rating available for asphalt shingles. A standard shingle does not pass that test.

Do I need a Class 4 shingle in Colorado?

In several Front Range cities you are required to install one by code. Everywhere else it is optional, but on the Front Range, where hail happens nearly every year, it is the shingle we recommend for most homeowners because of how well it holds up and how it can save you a large insurance deductible down the road.

What makes GAF ArmorShield II hold up to hail?

It is SBS modified, meaning synthetic rubber is mixed into the asphalt. That gives the shingle the flexibility to absorb a hail impact without cracking, which is why it passes the Class 4 UL 2218 test.

Do Class 4 shingles lower my homeowner's insurance?

Historically several carriers, including Farmers, State Farm, Allstate, and USAA, offered premium discounts. As of 2026 many of those discounts are changing, so confirm with your carrier. The bigger financial benefit is often avoiding a large deductible: if your Class 4 roof survives a storm, you do not have to file a claim or pay your deductible, which is frequently $5,000 to $8,000 now.

How much does a Class 4 upgrade cost?

In the real example in this guide, the homeowner paid about a $2,000 upgrade over a standard asphalt shingle. Your exact cost depends on roof size and product, and an accurate figure requires an inspection and measurement.

Which Colorado cities require Class 4 shingles?

Currently Fort Collins, Lafayette, Loveland, and unincorporated Boulder County require Class 4 by code. Denver, Northglenn, Westminster, and Thornton currently do not, though that can change. Always verify with your local building department.