Fire-Resistant Roofing Materials and Colorado’s WUI Roofing Codes

Key Takeaways

1. Concrete tile counts as Class A on its own only over a noncombustible deck, so on the plywood decking most Colorado homes have, the rating depends on the assembly underneath the tile.
2. Under Colorado’s wildfire code, the components that most often fall short are the eave venting under the tile and the underlayment beneath it.
3. On Point Contracting builds and documents Class A roof assemblies across the Front Range, Vail, and Summit County so homeowners have proof their carrier will accept.

How Fire-Resistant Roofing Materials Are Rated: Class A, B, and C

Fire performance in roofing is measured by a single classification system, tested under ASTM E108 or UL 790. Roofs are rated Class A, B, or C, and Class A is the top.

To earn it, a roof has to withstand four separate exposures: intermittent flame, flame spread across the surface, a burning brand placed on the roof, and flying brands. That last pair is what matters most in a wildfire, because burning brands are embers. A Class A roof is one expected to resist severe fire exposure, protect the deck beneath it, stay in position, and not throw off burning fragments of its own.

Here is how the fire-resistant roofing materials commonly installed in Colorado compare.

Material	Fire performance	What it takes to reach Class A	Colorado note
Concrete tile	Noncombustible, but deemed Class A without testing only over a noncombustible deck	Over the wood decking typical in Colorado, a listed assembly including the underlayment. The WUI code then adds ember protection where the tile profile leaves a gap	Roughly 900 to 1,100 pounds per square, so framing capacity has to be confirmed
Clay and barrel tile	Noncombustible, with the same deck condition as concrete tile	Same, and the eave detail matters more because the arch leaves larger openings	Terracotta and half-round profiles sit highest off the deck
Synthetic tile and shake	Class A available as a listed assembly	A specific underlayment is required. DaVinci products reach Class A with a single layer of SOLARHIDE	Far lighter than tile, where framing is a constraint
Standing seam metal	Noncombustible, with the same deck condition as tile	Over a wood deck, a listed assembly, usually with a specified barrier layer beneath the panel	Sheds snow aggressively, so snow retention is usually required
Class 4 asphalt shingle	Class A when installed per its listing	A listed underlayment, such as a qualifying synthetic	Lowest upfront cost. Carriers still scrutinize asphalt by age
Wood shake	Not Class A untreated	Not a viable path in a Colorado hazard zone	Effectively uninsurable in the WUI

What the 2021 Marshall Fire Changed About Roofing on the Front Range

The Marshall Fire started on December 30, 2021, burned roughly 6,000 acres, and destroyed 1,084 homes with 149 more damaged across Louisville, Superior, and unincorporated Boulder County. The state insurance commissioner later estimated insured losses at more than $2 billion.

What reset everyone’s thinking was the location. That fire was not in the mountains. It ran through graded suburban lots with irrigated lawns, which means wildfire roofing stopped being a Vail and Summit County conversation and became a Front Range one.

It also arrived as an ember shower rather than a wall of flame. The U.S. Fire Administration has pointed to landscape fabric in Superior, left perforated by the sheer density of embers falling on it. Federal fire research has repeatedly found that embers, not direct flame contact, cause most structure losses in wildland-urban interface fires.

The pressure has not eased since. Colorado burned roughly 256,000 acres in 2025, and the 2026 season has run harder, with the Aspen Acres Fire alone covering more than 100,000 acres and destroying over 300 homes.

What Colorado’s WUI Roofing Codes Require as of July 2026

Colorado adopted its first statewide wildfire building standard under Senate Bill 23-166. The Wildfire Resiliency Code Board adopted the Colorado Wildfire Resiliency Code in July 2025. Local jurisdictions had until April 1, 2026, to adopt it, and enforcement began July 1, 2026.

The WUI roofing codes Colorado now enforces apply to new construction and significant work rather than to roofs already in place, and requirements scale with your property’s mapped fire intensity classification. The threshold that matters most to homeowners is this: replacing 25 percent or more of a roof covering can pull the entire roof into compliance.

Here are the five components that decide whether your assembly passes.

1. Wide Eave Venting Beneath the Tile

Walk to the edge of a concrete tile roof, look up under the tile where it meets the gutter, and you will see openings running the length of the eave. That is intentional. Air enters there, travels up under the tile, and exits at the ridge, which helps keep the roof and the attic cool.

The problem is that the old detail left those openings wide. Wind-driven embers get pulled straight into that space, land on whatever is underneath, and start a fire inside the roof rather than on top of it. Nothing looks wrong from the ground while it is happening.

The current requirement closes that gap without restricting airflow. Picture a decorative fence with very fine openings, small enough that embers cannot pass but open enough that the roof still breathes. In the trade, these are bird stops or vented eave closures.

This matters most on barrel and half-round profiles, including terracotta. Those tiles arch higher off the deck, so the openings are considerably larger than on a flat or low-profile concrete tile.

What it takes to fix: Bird stops can usually be retrofitted at the eave without replacing the roof, though the first course of tile has to be lifted and reset carefully.

2. Combustible 30-Pound Felt Underlayment

This is the one almost nobody thinks about, and it is the one I would address first.

Most existing tile roofs in Colorado were installed over 30-pound asphalt-saturated felt. Felt is a capable water barrier and has been standard for decades, but it is combustible. Put an ember through an open eave vent onto a felt deck, and you have a fire in the one part of the roof nobody can see.

Better options exist, and they are what turn a fire-resistant material into a Class A assembly:

• SOLARHIDE by Eco Chief is a radiant barrier underlayment with a QAI Class A fire listing and an ICC-ES report ESR-4035. It works under concrete and clay tile, and DaVinci Roofscapes sells it for use with their synthetic systems.
• Tiger Paw by GAF is a synthetic underlayment that can be used to achieve a UL 790 Class A rating as a component of UL Classified assemblies, most often under shingle systems.

One related product category is worth separating, because people conflate it with fire performance. High-temperature self-adhered membranes such as Titanium PSU-30 and Grace Ice & Water Shield HT are engineered to resist flow at elevated temperatures, around 240 degrees for PSU-30. 

We use them under tile so the ice and water barrier does not soften and migrate in summer heat. That is a heat-stability specification, not a fire rating, and both jobs have to be handled.

What it takes to fix: Underlayment cannot be changed without removing the tile, so this is a re-roof or a full tile reset rather than a repair.

3. Undersized Valley Flashing and Cap Sheet

Valleys need corrosion-resistant metal of at least 0.019 inches, roughly 26 gauge, installed over a minimum 36-inch-wide cap sheet that meets ASTM D3909 and runs the full length of the valley.

Valleys collect debris and embers, so the code treats them as their own exposure. Older tile roofs often come up short here with lighter metal or an undersized underlayment strip.

What it takes to fix: Targeted valley rework, which means lifting and resetting the tile on both sides.

4. Combustible Vinyl Gutters and Downspouts

Gutters and downspouts have to be noncombustible. Vinyl does not qualify.

The logic matches the valleys. A gutter packed with needles and leaves is a fuel bed sitting at the roof edge, directly below the wide eave venting described earlier. A plastic gutter that softens under that load drops burning debris against your fascia and siding.

What it takes to fix: Aluminum or steel replacement with debris guards. Inexpensive relative to its effect on your risk profile.

5. Quarter-Inch Attic and Soffit Vent Screening

Ventilation openings for attics, enclosed rafter spaces, and underfloor spaces need noncombustible corrosion-resistant mesh with openings no larger than one-eighth inch.

Standard screening is usually a quarter-inch, which lets through embers small enough to smolder in blown insulation for hours before anyone notices. Federal researchers have documented firebrands entering buildings through air vents and igniting the materials inside.

What it takes to fix: Rescreening is the least expensive item on this list and one of the first things a mitigation inspector checks.

Put side by side, here is how a typical older tile roof compares with what the code now requires.

Component	Typical older tile roof	Current requirement
Eave venting	Open gaps under the tile, largest on barrel profiles	Vented bird stops or eave closures with ember-sized openings
Underlayment	30-pound asphalt-saturated felt	Listed Class A assembly component, such as SOLARHIDE or an equivalent
Valley flashing	Light-gauge metal, narrow underlayment	0.019-inch minimum metal over 36-inch ASTM D3909 cap sheet
Gutters	Frequently vinyl	Noncombustible metal
Vent screening	Quarter-inch mesh	One-eighth-inch noncombustible mesh

Every item in that column is a code requirement. The high-temperature ice-and-water membrane described earlier is not on the list because nothing in the wildfire code requires it. We specify it anyway for heat durability under tile, and it belongs in your scope for that reason rather than for compliance.

Best Roofing Material for Colorado Homeowners

Colorado’s hail, heavy snowfall, high winds, and rapid temperature swings each stress a roof differently, and no single material handles all four equally well. 

Slate can last more than a century and shrugs off the freeze-thaw cycling that cracks lesser materials, though its weight means most homes need reinforced framing before it can go on. Metal and DaVinci synthetic systems last 40 to 70 years with simpler installation and no structural upgrades, while asphalt remains the least expensive to install upfront. 

See how the major roofing materials compare on impact resistance, longevity, weight, and maintenance.

Do Colorado’s WUI Roofing Codes Apply to an Existing Roof?

Not until you touch the roof. These requirements attach to new construction and to re-roofs rather than to roofs already in place, so a sound tile roof you are not planning to work on triggers nothing. What matters is how easily that changes.

A hail claim is the common way in. Replacing 25 percent or more of the covering can pull the whole roof into compliance, and Colorado roofs take hail often enough that this is a routine event rather than a rare one. That is a scope question worth settling before the tear-off rather than after. Insurance is the other way in, and it is where most homeowners hit this for the first time.

Why Colorado Insurance Carriers Are Asking About Your Roof Assembly

If you are having trouble getting a concrete tile roof covered, it is almost always because the roof is not a Class A assembly, not because there is anything wrong with the tile. Carriers have gotten much sharper about this distinction since the Marshall Fire. 

When I sit down with an underwriter now, the question is rarely what the roof is made of. It is what sits underneath it and how the eaves are detailed.

It helps to know what wildfire actually does to your policy. The Colorado Division of Insurance surveyed 20 carriers in February 2026 and found that hail accounts for 26 to 54 percent of premiums, depending on the county, while wildfire accounts for 0.9 to 24.6 percent. 

In Summit County, hail accounted for 35.6 percent of the average premium, compared with 7.9 percent for wildfire. 

House Bill 25-1182 took effect on July 1, 2026, the same day the wildfire code became enforceable. Carriers using wildfire risk models now have to disclose their wildfire risk score in an annual written notice, publish available mitigation discounts and the appeal process, and either build parcel-level mitigation into their models or discount policyholders who can prove the work was done. You can appeal your score directly to the insurer.

What actually moves an underwriter is documentation:

• Photographs taken during installation, not after. Nobody can verify a bird stop or an underlayment once the tile is down.
• An itemized scope naming the underlayment product and its listing, the eave closure method, valley flashing gauge, gutter material, and vent mesh size.
• Permit records and final inspection sign-off from your jurisdiction.
• Third-party designation. The IBHS Wildfire Prepared Home program came to Colorado in April 2026 and verifies the entire system rather than a single component. In Boulder County, Wildfire Partners certification is recognized by several named carriers.
• The zero-to-five-foot noncombustible zone. No roof detail survives a mulch bed pressed against the siding.

How On Point Contracting Builds and Documents Class A Roof Assemblies

Getting a roof to Class A comes down to three things: the right material, the right assembly underneath it, and paperwork your carrier will accept. We handle all three.

On Point Contracting is a family-owned Colorado roofing contractor based in Littleton, serving Cherry Hills Village, Greenwood Village, Hilltop, Englewood, Ken Caryl, and Castle Rock, and expanding into Summit County, Vail, and Breckenridge. 

We install concrete tile, DaVinci synthetic slate, standing-seam metal, and Class 4 shingle systems, along with engineered snow retention for high-altitude properties.

Because our team comes from insurance adjusting, we manage claims from documentation through final inspection, and we photograph the assembly as it goes on rather than asking you to take our word for it afterward.

What You Should Do Next

1. Look up your property on the state wildfire hazard map and confirm your fire intensity classification with your local building department.
2. Ask your insurer for your wildfire risk score now instead of waiting for renewal, and gather permits, invoices, and dated photos before you consider an appeal.
3. Schedule a free inspection with On Point Contracting. We will tell you in writing what your assembly actually is and whether you need a retrofit, a re-roof, or neither.

Frequently Asked Questions