Everything You Need to Know About Class 4 Roofs

Colorado sits in the heart of Hail Alley, and hail losses account for a large share of what homeowners along the Front Range pay for property insurance. Colorado Insurance Commissioner Michael Conway has estimated that half or more of the average Colorado homeowners premium goes toward hail losses. Every roof replacement conversation in this state eventually arrives at the same question: is the Class 4 upgrade worth the money?

The answer depends on how long a homeowner plans to stay in the house, what the insurance policy actually says, and which version of Class 4 ends up on the roof. Excel Roofing has been replacing roofs in Colorado and Wyoming since 1993 and has handled warranty and insurance claims with every major product line on the market. What follows is a straight explanation of what the rating measures, which materials carry it, what it costs, and how the insurance discount really works.

What Class 4 Actually Means

Class 4 is a test result, not a brand or a product line. It comes from UL 2218, the impact resistance standard published by Underwriters Laboratories. In the test, a steel ball is dropped onto an installed roofing sample from a fixed height, twice in roughly the same spot. The sample passes if the back side shows no tearing, fracturing, cracking, splitting, or any other opening through the roof covering.

Four classes exist. Each one uses a larger ball dropped from a greater height.

Class 4 is the highest rating available under UL 2218, and it is the threshold nearly every insurance carrier uses when deciding whether a roof qualifies for an impact resistant discount. Class 3 products perform better than standard shingles, but they rarely trigger any premium credit.

One detail matters more than any other, and it is the detail most homeowners are never told: the test measures whether the roof still functions as a water barrier. It does not measure appearance. Dents, bruising, and granule loss are all permitted under a passing result.

UL 2218 Versus FM 4473, and Why Colorado Homeowners Should Care

A second standard, FM 4473, tests the same idea with a different projectile. Instead of steel balls, FM launches molded ice balls at the roofing material, which is closer to what actually falls on a Denver rooftop in hail season.

FM 4473 also includes a tier above Class 4 called 'Very Severe Hail', or VSH. The VSH test uses two inch ice balls at nearly double the kinetic energy of the standard Class 4 test, and it requires the samples to be artificially aged before testing. UL 2218 has no equivalent tier.

That aging requirement is the part worth pausing on. A brand new shingle in a laboratory is not the same product as a twelve year old shingle that has been baked by high altitude sun and cycled through hundreds of Colorado freeze and thaw cycles. A product carrying both FM 4473 Class 4 and VSH has been tested closer to the conditions a Front Range roof lives in. Very few products carry it. Westlake Royal Unified Steel is one of them, which is a large part of why Excel Roofing treats stone-coated steel as one of the strongest hail answers available in this market.

What Class 4 Does Not Mean

Class 4 is a meaningful upgrade. It is not body armor, and homeowners who expect it to be are the ones who end up disappointed after a storm.

• Class 4 is not hail proof. A large enough stone, driven hard enough, can still damage a Class 4 roof. The rating raises the threshold, it does not eliminate it.
• Cosmetic denting still happens. Bruising and granule displacement are allowed under a passing test result, and they will show up on a Class 4 roof after a serious storm.
• The rating covers the shingle, not the roof system. Ridge vents, turtle vents, pipe boots, flashing, gutters, downspouts, garage doors, siding, window screens, skylights, and air conditioner fins are all still exposed.
• The rating does not describe wind performance. Impact resistance and wind resistance are separate properties measured by separate tests.

That last point deserves emphasis. As Excel Roofing's asphalt shingle comparison breaks down in detail, wind performance comes from two things: the nailing zone and the seal down strip. Owens Corning's patented SureNail strip gives installers a reinforced, forgiving target with roughly 50% overlap between shingle layers. Pabco runs closer to 75% overlap. GAF sits near 25%. Tamko offers only a thin line as a target. None of that is captured by an impact class. A homeowner choosing purely on the Class 4 label can still end up with a roof that is vulnerable to the wind events that follow most Colorado hailstorms.

Two Very Different Ways a Shingle Earns Class 4

This is the single most useful thing a homeowner can learn before signing a contract. Two shingles can both be legitimately labeled Class 4, both qualify for the same insurance discount, and perform quite differently on a Colorado roof, because manufacturers reach the rating through two different engineering approaches.

Polymer modified asphalt

The shingle's asphalt is blended with a rubber polymer, most commonly SBS, which is styrene-butadiene-styrene. The result is a shingle that stays flexible in cold weather and absorbs impact energy the way a rubber mat does, flexing and rebounding rather than fracturing. Owens Corning Duration FLEX, Malarkey's NEX product line, and CertainTeed Landmark IR all work this way.

Reinforcing mesh or scrim

A woven reinforcing layer is bonded to the back of an otherwise conventional shingle. The mesh keeps the fiberglass mat from cracking through when a stone hits, which is exactly what the UL 2218 test measures. Owens Corning Duration STORM, with its WeatherGuard backing, is the best known example.

Both approaches pass the same test and both earn the same rating. The difference shows up over time. A mesh backed shingle resists cracking through, but it does less to protect the surface of the shingle from bruising and granule loss. A polymer modified shingle protects the surface as well as the mat. In a market that takes multiple significant hail events per decade, that distinction compounds.

Excel Roofing steers homeowners toward polymer modified products when the budget allows.

Class 4 Is Available in 4 Very Different Materials

Class 4 is not an asphalt only category. Concrete tile, stone-coated steel, and synthetic composite tile all carry the rating, and each behaves differently under hail than asphalt does. The numbers below reflect how Excel Roofing rates real world hail performance across the four material families.

A roofing square equals 100 square feet of roof surface. These ranges, are Colorado and Wyoming estimates for a typical residential roofing project and will change with roof pitch, complexity, access, decking condition, and material availability. An accurate number requires measurement and a roof inspection.

Class 4 Asphalt

The most common upgrade by a wide margin, and the least expensive path to a discount-qualifying roof. Modern Class 4 asphalt looks essentially identical to standard architectural shingles, from the ground. It weighs roughly 250 to 310 pounds per square, compared with 220 to 280 for standard architectural, a difference that is not relevant for any roof structure built to current code. The trade off is that asphalt bruises and will still show hail marks after a serious storm.

Concrete tile

Class 4 concrete tile carries a 40 to 50 year service life and handles Colorado sun exceptionally well. Individual tiles can crack under very large hail stones, but a cracked tile is replaced individually rather than triggering a full roof replacement. The main constraint is weight. Concrete tile requires verification that the structure can carry the load, and switching to it from asphalt often means a structural review.

Stone-coated steel

This is one of the strongest answers to hail Excel Roofing installs. Westlake Royal Unified Steel is rated for 120 mph winds, carries Class 4 and VSH under ANSI FM 4473, holds a Class A fire rating, and comes with a 50 year fully transferable warranty. Steel can dent under extreme impact, but it does not crack, split, or lose its ability to shed water. The higher cost buys a roof that is realistically, the last one many homeowners will buy for that home.

Synthetic composite tile

Brava is the synthetic composite Excel Roofing installs, and every Brava profile carries a Class 4 impact rating, including Cedar Shake, Old World Slate, and Spanish Barrel Tile. The tile is compression molded from recycled polymer using mineral pigments, the same class of pigment found in high end clay tile. Those pigments are what allow Brava to stand behind a 10 year fade warranty inside a 50 year transferable product warranty, and anything installed above 4,000 feet gets a high UV package as standard, which matters at Front Range and mountain elevations where ultraviolet exposure is far higher than at sea level.

Under hail, Brava behaves closer to steel than to asphalt. In practice it resists anything short of grapefruit sized stones without cracking or splitting. It weighs roughly 300 pounds per roofing square, which means it installs over framing built for asphalt shingles with no structural reinforcement, a meaningful advantage over concrete tile for homeowners who want the look of slate or cedar shake. Brava is also available in Class A fire rated assemblies, which has become a code question rather than a preference in Colorado's wildfire zones, and it carries ICC, Wildland Urban Interface, Miami-Dade, and Texas Department of Insurance approvals. The warranty runs 50 years and the realistic service life is closer to 60.

Named Class 4 Products by Manufacturer

Class 4 status attaches to specific product lines, not to a brand as a whole. A shingle described as architectural or dimensional is not automatically Class 4. The rating has to appear on that specific product's data sheet. Here is a table with some of the most common Class 4 roofing materials, Excel Roofing offers.

Excel Roofing is an Owens Corning Platinum Preferred Contractor, and Owens Corning ranks first in the company's independent shingle rankings on the strength of the SureNail nailing zone and a ten year non prorated warranty available when five Owens Corning products are installed together. Homeowners should still ask to see the current product data sheet for whichever line they choose, and should confirm the UL 2218 or FM 4473 listing on that sheet before signing.

The Insurance Discount, Explained Properly

The insurance credit is the reason most Colorado homeowners consider Class 4 in the first place, and it is also where the most expensive misunderstandings happen.

What the discount is worth

Carriers writing in Colorado commonly file impact resistant roof discounts in the range of five to thirty percent, with most homeowners landing somewhere between ten and twenty five percent. Nationally the range runs as wide as five to thirty five percent. The number varies by carrier, by policy, and by address.

The critical detail is what the percentage applies to. Many carriers apply the credit only to the wind and hail portion of the premium rather than the entire policy. In a hail exposed state that portion is substantial, often thirty to fifty percent of the total, but a homeowner who assumes the discount applies to the whole premium will be disappointed by the first renewal.

What carriers require to grant it

The order of operations matters. Homeowners should confirm with their agent, in writing and before the roof goes on, which specific products qualify with their carrier. Approving a product after installation is far harder than approving it before.

• A certificate of installation or completion from the roofing contractor identifying the product installed.
• The manufacturer's product data sheet showing the UL 2218 Class 4 or FM 4473 listing.
• Photographs of the completed roof, requested by some carriers.
• A carrier specific form in some cases. USAA, for example, uses a dedicated impact resistant roof discount form.

The cosmetic damage exclusion

This is the part of the conversation that catches Colorado homeowners off guard, and it deserves more attention than it usually gets.

A growing number of carriers now attach a cosmetic damage endorsement to policies, and several tie that endorsement directly to the impact resistant roof discount. The standard ISO language, endorsement HO 04 93, excludes damage that does not prevent the roof from functioning as a barrier against the elements. Carriers including State Farm, Safeco, and Allstate have used endorsements of this type, and USAA pairs a cosmetic damage exclusion with its impact resistant discount.

In practice the endorsement means that dents, dings, and marred granules are the homeowner's problem, not the carrier's, no matter how bad the roof looks. Since Class 4 products are specifically designed to keep functioning after impacts that would breach a standard shingle, the exclusion and the product interact in an uncomfortable way. The roof keeps working, the claim is denied, and the homeowner lives with the appearance.

None of that makes Class 4 a bad decision. It makes the policy language something to read before signing. Excel Roofing recommends every homeowner ask their agent four specific questions:

• Does this discount require a cosmetic damage exclusion endorsement, and may I see the exact language?
• Does the discount apply to the full premium or only to the wind and hail portion?
• Is roof settlement on a replacement cost basis or an actual cash value basis, and is there a roof payment schedule tied to age?
• What is the wind and hail deductible, and is it a flat dollar amount or a percentage of the dwelling value?

Percentage deductibles of one to five percent have become common in Colorado. On a home insured for $600,000, a two percent wind and hail deductible is $12,000 out of pocket before the carrier pays anything, which changes the entire calculation of what a claim is worth filing.

The renewal angle nobody advertises

Colorado's homeowners insurance non renewal rate has recently exceeded Texas's in federal data, and the two biggest triggers are claim frequency and roof age. A Class 4 roof that survives a storm without generating a claim is protecting more than a deductible. It is protecting the policy itself. For homeowners with a claim already on file, that consideration can outweigh the premium discount entirely.

Is Class 4 Worth It? Start With This One Question

Excel Roofing's answer to every material question starts the same way: how long does the homeowner plan to stay in the house? That single answer reorganizes everything else.

• Zero to five years. Standard architectural asphalt usually makes financial sense. There is not enough time to recover the Class 4 premium through insurance savings, and the resale bump rarely covers the gap.
• Five to ten years. Class 4 asphalt is generally the right call. The discount has time to work, and the roof is far more likely to survive a storm cycle without a claim.
• Ten years or more. Stone coated steel, Brava synthetic composite tile, or concrete tile usually delivers better value than asphalt. The cost per year of service drops sharply, and the 50 year transferable warranties on stone-coated steel and Brava follow the home if plans change.

The payback math

A useful way to frame it. Upgrading a typical Colorado roof from standard architectural to Class 4 asphalt costs roughly $2,000 to $4,000 more. A twenty percent discount on a $2,400 annual premium returns about $480 per year. That recovers the upgrade in five to eight years, and everything after that is net savings, before counting a single avoided deductible.

Add one avoided claim and the math stops being close. A homeowner who does not file after a moderate storm keeps the deductible, keeps the claim off the record, and keeps the renewal.

How Excel Roofing Presents the Options

Every Excel Roofing estimate is written in three tiers so homeowners can see the trade offs side by side rather than comparing a single number against nothing.

Frequently Asked Questions

What is a Class 4 shingle?

A Class 4 shingle, tile or panel is a roofing product that has passed the UL 2218 impact resistance test at its highest level, withstanding a two inch steel ball dropped from 20 feet, twice in the same spot, without cracking, splitting, or rupturing through the back. Class 4 is the top of a four level scale and is the threshold most insurance carriers use for impact resistant roof discounts.

Do Class 4 shingles stop hail damage completely?

No. Class 4 shingles resist the structural damage that lets water into a home, but they can still be dented and can still lose granules. The rating also covers only the shingle itself, not vents, flashing, gutters, siding, skylights, or air conditioner fins. Class 4 raises the threshold for damage rather than eliminating it.

How much do Class 4 shingles cost in Colorado?

Class 4 asphalt shingles typically run $5.50 to $8.00 per square foot installed, or roughly $550 to $800 per roofing square, compared with $4.50 to $6.50 per square foot for standard architectural shingles. On a typical Colorado home the upgrade adds about $2,000 to $4,000. Labor is essentially the same, so nearly the entire premium is material cost.

How much can a Class 4 roof save on homeowners insurance in Colorado?

Carriers writing in Colorado commonly file impact resistant roof discounts between five and thirty percent, with most homeowners seeing ten to twenty five percent. Many carriers apply the credit only to the wind and hail portion of the premium rather than the entire policy, so the actual dollar savings should be confirmed with the agent before the roof is installed.

What is the difference between UL 2218 Class 4 and FM 4473 Class 4?

UL 2218 drops steel balls onto new roofing samples. FM 4473 launches molded ice balls, which is closer to real hail, and it includes a Very Severe Hail tier above Class 4 that uses higher energy impacts on artificially aged samples. UL 2218 has no equivalent tier, so an FM 4473 Class 4 plus VSH rating represents a tougher standard.

Do Class 4 shingles look different from regular shingles?

No. Modern Class 4 asphalt shingles are visually almost indistinguishable from standard architectural shingles and come in the same color ranges. They are slightly heavier and thicker, but the difference is not visible from the ground.

Does a Class 4 roof require extra structural support?

Class 4 asphalt shingles weigh about 250 to 310 pounds per roofing square compared with 220 to 280 for standard architectural shingles, a difference that is negligible for any roof framed to current building code. Brava synthetic composite tile weighs roughly 300 pounds per roofing square and also requires no reinforcement. Concrete tile is a different matter and does require verification that the structure can carry the additional load.

Can a Class 4 roof still be replaced by insurance after a hailstorm?

Yes, if the storm causes functional damage that compromises the roof's ability to shed water. However, some policies carry a cosmetic damage exclusion, often tied to the impact resistant discount itself, which removes coverage for dents and granule loss that do not affect performance. Homeowners should read that endorsement carefully before accepting the discount.

Which is better for Colorado hail, Class 4 asphalt or stone-coated steel?

Stone coated steel performs better. Excel Roofing rates stone coated steel a nine out of ten for hail performance against a seven out of ten for Class 4 asphalt, and products such as Westlake Royal Unified Steel carry both Class 4 and Very Severe Hail ratings under FM 4473 along with a fifty year transferable warranty. Class 4 asphalt costs considerably less and is the better value for shorter ownership horizons.

Is Brava synthetic roof tile Class 4?

Yes. Every Brava composite profile carries a Class 4 impact rating, including Cedar Shake, Old World Slate, and Spanish Barrel Tile, and Brava backs the product with a 50 year transferable warranty. It is also available in Class A fire rated assemblies that satisfy Colorado wildfire code requirements, weighs roughly 300 pounds per roofing square so no structural reinforcement is needed, and ships with a high UV package on anything installed above 4,000 feet.

Are Class 4 shingles required by code in Colorado?

No Colorado jurisdiction currently requires Class 4 impact resistance for residential roofing. Local codes do regulate wind ratings, fire ratings, and in some mountain and wildfire zones the roof covering class, so requirements should always be confirmed with the local building department before material selection.

The Bottom Line

Class 4 is a genuine upgrade that pays for itself for most Colorado homeowners who plan to stay in their home more than five years. It is not a guarantee against hail, the rating is earned two different ways with meaningfully different long term results, and the insurance discount frequently arrives attached to policy language that homeowners should read before accepting it. A roof decision made with those three facts in hand is a good decision regardless of which product ends up on the house.

Excel Roofing has served Colorado and Wyoming homeowners since 1993 from offices in Englewood, Colorado Springs, Sheridan, and Casper. Every estimate includes a full inspection, documented measurements, product data sheets, and the paperwork insurance carriers require for an impact resistant discount. You don't pay a cent until you're content.

Schedule a free roof inspection at excelroofing.com.