Ask anyone who has lived here a few years and they will tell you the same story: jacket in the morning, t-shirt by noon, sunburn by two, freezing again the next day. It is a running joke in Colorado. It is not a joke for the roof over your head.

J Bretz, Founder and CEO of Excel Roofing, sat down with Octavian Avila, Regional Sales Leader for the Mountain Region at Owens Corning, to talk through exactly what this climate does to an asphalt shingle and what has changed in the last few years in the products built to survive it.

Why Colorado Is One of the Harshest Environments in the Country for a Roof

Octavian’s coverage area runs the length of the mountain time zone, from Montana down to New Mexico. He has seen what every climate in that corridor does to roofing material, and Colorado sits at the difficult end of it.

The reason is not any single condition. It is the combination, and how fast weather conditions change.

Temperature Swing and Freeze-Thaw

Colorado sees several days in the triple digits, several days in the negatives, and the swing between them can happen inside a single afternoon. Asphalt expands when it heats up and contracts when it cools. Do that a few thousand times and you are working a material back and forth until something gives and this happens at the seams, the fasteners and the edges.

Freeze-thaw compounds it. Water gets into a small opening, freezes, expands, and makes the opening slightly larger. Then it does it again the next night.

High-Altitude UV

Elevation means less atmosphere between your roof and the sun. A shingle in Denver takes more ultraviolet exposure than the identical shingle at sea level, and UV is what breaks down the asphalt binder that holds the whole thing together. As Octavian puts it, being higher up causes the shingles to take more of a beating.

This is a slow, invisible form of aging. It does not show up as a leak. It shows up as a roof that becomes brittle years earlier than its warranty implies, which matters enormously when the hail arrives.

Hail

Hail is the headline. It is the reason Colorado roofing conversations look different from roofing conversations almost anywhere else in the country, and it is the reason impact resistance has become the deciding factor for most homeowners here.

What a Class 4 Rating Actually Means

Class 4 is not a marketing term. It is the classification of a standardized impact test.

In Octavian’s description, a steel ball is dropped onto the shingle from a set height to mimic what hail does on impact. The shingle is then examined for cracking or splitting, specifically on the backside. The backside of the shingle is the make or break point of this test, if there is crack, tearing or any other sign of failure, the shingle fails the class 4 test. A shingle that passes at the most demanding level earns Class 4, the highest impact-resistance classification available under the UL 2218 standard.

One honest caveat worth stating plainly: Class 4 means a shingle passed a test. It does not mean the roof is indestructible. Severe hail can still damage a Class 4 roof, and it can damage vents, flashing, gutters and other components regardless of what the shingles are rated. After a significant storm, an inspection is still the right move.

Owens Corning Now Offers Four Class 4 Shingles, Not Two

This is the genuinely new information in the conversation, and most homeowner research online has not caught up to it yet. Here are all of the Class 4 asphalt shingle offerings from Owens Corning:

TruDefinition Duration STORM

The longtime staple. Duration STORM uses a polymeric backing on the underside of the shingle that absorbs and resists the indentation caused by impact. It has been the default impact-resistant option in this market for years, and it earns its reputation.

TruDefinition Duration FLEX

Introduced around 2018, Duration FLEX uses SBS-modified asphalt, rubberized asphalt, throughout the shingle rather than a backing layer. Octavian’s shorthand for it, is bouncing: hail hits, the shingle flexes, and the energy is absorbed rather than transferred through the mat.

The second benefit is installation. SBS shingles stay pliable across a much wider temperature range, hot or cold, which reduces the handling damage that conventional shingles are prone to when a crew is working in the wrong weather. In a climate where the wrong weather arrives without warning, that matters.

Woodmoor and Woodcrest

These are the premium end of the Owens Corning line, built to reproduce the depth and shadow line of cedar shake without the maintenance, the fire risk or the cost of real wood. Within the last several months, both became Class 4 rated.

That is a meaningful change. Until recently, a homeowner who wanted the shake look in a hail market had to weigh appearance against impact resistance. That tradeoff is gone.

If you are trying to decide between these four, we go product by product in Owens Corning Shingles Explained: Class 4 Ratings, SureNail Technology, and the 160 MPH Wind Warranty — including how SureNail affects wind performance and what the warranty actually covers.

What Owens Corning Platinum Preferred Means for a Homeowner

Excel Roofing has installed Owens Corning shingles since the company started roofing in 1993, and became a Platinum Preferred Contractor in 2012. Octavian describes Platinum contractors as the top one percent of roofing contractors in the country.

The designation is not something a company buys. It is earned through workmanship standards, financial stability, licensing, insurance and customer satisfaction scores, and it has to be maintained. J Bretz has also served on the Owens Corning Platinum Advisory Board, which gives contractors a direct line to the manufacturer on what is and is not working in the field.

For a homeowner, the practical value is the warranty. Platinum Preferred contractors can offer manufacturer-backed system warranties that non-certified contractors cannot, which means the coverage does not disappear if the installing company does.

How to Choose a Roofing Contractor in Colorado

Asked for closing advice, both men gave short answers.

Octavian’s: look for the Platinum badge, and look for Owens Corning shingles with a Class 4 rating.

J Bretz added two more, and they are worth taking seriously as filters when you are collecting bids:

• Never pay a cent until you are content. A contractor asking for a large deposit before material is on site is asking you to carry their risk.
• Do not sign a contract with cancellation fees. A company confident in its work does not need to trap you in the agreement.

Frequently Asked Questions

Why is Colorado so hard on roofs?

Three conditions compound each other: extreme temperature swings that drive expansion, contraction and freeze-thaw cycling; elevated UV exposure from high altitude that breaks down asphalt binder faster; and frequent, severe hail. A roof here ages faster than the same roof in a milder climate.

What is a Class 4 shingle?

A Class 4 shingle has passed the highest level of the UL 2218 impact-resistance test, in which a steel ball is dropped onto the shingle to simulate hail. It is the top impact classification available for asphalt shingles.

Which Owens Corning shingles are Class 4?

Four: TruDefinition Duration STORM, TruDefinition Duration FLEX, Woodmoor and Woodcrest. Woodmoor and Woodcrest are the most recent additions to the list.

What is the difference between Duration STORM and Duration FLEX?

Both are Class 4, but they achieve it differently. Duration STORM uses a polymeric backing on the underside of the shingle to resist indentation. Duration FLEX uses SBS-modified asphalt throughout, so the shingle flexes and rebounds on impact and stays pliable across a wider installation temperature range.

Do Class 4 shingles stop hail damage completely?

No. Class 4 means the shingle passed a standardized impact test, not that it cannot be damaged. Severe hail can still damage a Class 4 roof, and it can damage gutters, vents and flashing regardless of the shingle rating. Have the roof inspected after any significant storm.

What does Owens Corning Platinum Preferred mean?

It is Owens Corning’s highest contractor certification, held by roughly the top one percent of roofing contractors nationally. It requires meeting standards for workmanship, licensing, insurance, financial stability and customer satisfaction, and it allows the contractor to offer manufacturer-backed system warranties.

Get a Straight Answer About Your Roof

Excel Roofing has been installing roofs in Colorado since 1993 and has been an Owens Corning Platinum Preferred Contractor since 2012. Every roof system we install is built for the climate it actually has to survive.

Schedule a free inspection and a member of the team will walk the roof, document what is there, and explain your options before any decision is made.

You Don’t Pay A Cent Until You’re Content.

We’re On Top Of It.