What Is a Class 4 Impact-Resistant Shingle?

If you live in Central Arkansas, you’ve probably heard roofers talk about Class 3 and Class 4 shingles, especially after a hailstorm.

But what does a Class 4 rating actually mean?

Simply put, Class 4 is the highest impact-resistance rating available under the UL 2218 testing standard. It means the shingle has passed a controlled laboratory test designed to measure how roofing materials respond to impact.

For homeowners in a hail-prone area like Central Arkansas, I think that makes Class 4 shingles one of the most worthwhile upgrades to consider when replacing a roof.

It does not mean the shingle is completely hail-proof, but it does mean the product has demonstrated a higher level of impact resistance than Class 3 and unrated shingles.

What Does a Class 4 Impact Rating Actually Mean?

UL 2218 is a standardized impact-resistance test for roofing materials.

For a Class 4 test, a 2-inch steel ball is dropped from a height of 20 feet onto multiple vulnerable areas of the roofing material. The material is then inspected for cracking through the shingle. Class 4 is the highest rating available under this test.

One thing homeowners should understand is that this is a laboratory test, and no laboratory test can perfectly recreate every hailstorm.

Real hailstones vary in size, hardness, shape, wind speed, and angle of impact.

That doesn’t take away from the value of the Class 4 rating. It simply means I would describe a Class 4 shingle as more impact resistant, not indestructible.

And in an area where hail damage is common, greater impact resistance is a real advantage.

Class 3 vs. Class 4: What’s the Difference?

The main difference is the amount of impact the material has to withstand during UL 2218 testing.

That quarter-inch difference may not sound dramatic, but the larger steel ball and greater drop height create substantially more impact energy.

For a homeowner, the easiest way to think about it is this:

Class 3 is a good impact-resistant shingle. Class 4 is the next step up.

That is one of the reasons I generally like the Class 4 option for homeowners who want to put a more durable roofing system on their home.

Class 4 Is Built for Better Impact Resistance

No asphalt shingle can be guaranteed to survive every possible hailstorm without damage.

But that doesn’t mean all shingles perform the same.

A Class 4 shingle has gone through more demanding impact testing than a Class 3 or unrated product. For homeowners throughout Central Arkansas, that matters.

We live in an area where severe thunderstorms and hail are a legitimate part of owning a home. If I’m choosing between two otherwise good roofing systems and one gives me a higher level of tested impact resistance, I see real value in that upgrade.

Are All Class 4 Shingles Made the Same Way?

No.

Class 4 is a performance rating, not one particular type of shingle.

Manufacturers use different technologies to achieve the rating.

Some impact-resistant shingles use SBS-modified asphalt, which adds a rubber-like polymer to the asphalt and gives the shingle more flexibility.

Other Class 4 shingles use stronger fiberglass mats or other reinforcement technologies.

For example, GAF’s current Timberline UHDZ with UltraMat achieves a Class 4 rating through an enhanced fiberglass mat designed to improve impact performance.

This is why I wouldn’t compare shingles based only on the words “Class 4.”

I would also look at:

The impact rating is important, but the best roof is still a complete roofing system installed correctly.

GAF HDZ vs. UHDZ: A Practical Example

One comparison we regularly make for homeowners is between GAF Timberline HDZ and Timberline UHDZ.

As of 2026, qualifying Timberline HDZ shingles carry a UL 2218 Class 3 impact-resistance rating, while qualifying Timberline UHDZ shingles with UltraMat carry a Class 4 rating.

HDZ is already a very good architectural shingle and is one of the products we install regularly.

The UHDZ is the premium step up.

For homeowners who want greater impact resistance, a heavier-duty roofing system, and the additional features that come with the UHDZ product, I think the Class 4 upgrade can make a lot of sense—especially here in Central Arkansas where hail-producing storms are not a matter of if, but when.

When the budget allows, I generally prefer putting the more durable product on the roof, particularly when we’re talking about a system that’s expected to protect the home for decades.

How Class 4 Shingles Have Improved

Impact-resistant roofing technology has come a long way.

The first edition of the UL 2218 standard was published in 1996 to provide a standardized way to compare the impact resistance of steep-slope roofing materials.

Since then, manufacturers have continued developing stronger shingles through advancements such as polymer-modified asphalt, improved fiberglass mats, and other reinforcement technologies.

Modern Class 4 shingles give homeowners options that simply weren’t as widely available on residential roofs decades ago.

For someone replacing a roof today, I think it makes sense to at least consider taking advantage of those improvements rather than automatically replacing an older roof with the same basic level of material.

Can a Class 4 Roof Lower Your Insurance Premium?

In some cases, yes.

Some insurance companies offer premium discounts for homes with qualifying impact-resistant roofing, including Class 4 shingles.

The amount varies by carrier and policy, so I always recommend checking with your insurance agent.

Ask them:

“If I install this specific UL 2218 Class 4 shingle, does my policy offer an impact-resistant roof discount?”

If it does, that’s another benefit of making the upgrade.

I wouldn’t choose a Class 4 roof solely because of a possible insurance discount, but if you’re already gaining better impact resistance and your insurance company gives you a lower premium as well, that can make the upgrade even more attractive.

Why I Like Class 4 for Central Arkansas Homes

If I were replacing a roof in an area that almost never saw hail, the Class 4 rating might not carry the same weight.

But that’s not Central Arkansas.

We regularly deal with thunderstorms, wind, and hail throughout Garland County, Saline County, and the surrounding areas.

For that reason, I think impact resistance is one of the more practical places to spend money when upgrading a roofing system.

As far as cosmetic upgrades homeowners can make to a roof, often times Class 4 shingles are going to add curb appeal, and they are a step up in their design in addition to impact performance.

You’re paying for a roofing product that has demonstrated a higher level of resistance to impact, and that’s a performance feature that makes sense for the weather we experience here.

Is a Class 4 Shingle Worth the Extra Cost?

For many homeowners in Central Arkansas, I think the answer is yes.

Of course, every homeowner has a budget, and Class 3 shingles can still be a very good choice. Class 4 shingle, while not indestructible, is the highest impact-resistance classification under the UL 2218 standard.

You’re getting:

If I’m comparing where to spend extra money on a roof, durability is usually near the top of my list.

For homeowners in Hot Springs, Hot Springs Village, Benton, Malvern, and throughout Central Arkansas, I think Class 4 shingles are an excellent option for anyone wanting to build a stronger, more storm-resistant roofing system.

The goal isn’t to promise that hail can never damage your roof.

It’s to give your home the best reasonable chance of handling the next storm well.