Asphalt shingles are made by coating a fiberglass mat with weathering-grade asphalt on both sides, pressing mineral granules into the hot top surface, adding a heat-activated sealant strip, and then cutting the sheet into 3-tab shingles or laminating two layers into architectural shingles. Each layer has one job: the mat gives strength, the asphalt keeps water out, the granules block the sun, and the sealant bonds each course to the one below so wind cannot lift it. Owens Corning describes its 3-tab stack, top to bottom, as sealant, mineral granules, weathering-grade asphalt, fiberglass mat, and weathering-grade asphalt again.
The layers, and what each one does on your roof
| Layer | Made from | Its job | What failure looks like |
|---|---|---|---|
| Fiberglass mat | Glass fibers formed into a thin sheet | Strength and shape; does not soak up water | Cracks or splits through the shingle |
| Weathering-grade asphalt (both sides) | Refined asphalt, applied hot | Waterproofing; holds the granules | Brittle, curling or blistered shingles |
| Mineral granules | Crushed rock with a ceramic color coat | Block UV, add color, add fire resistance | Bare black spots, granules piling in gutters |
| Sealant strip | Heat-activated adhesive | Bonds each course into one watertight unit | Tabs that lift or flap in wind |
| Second layer (laminates only) | A second coated mat bonded to the first | Thickness, shadow lines, wind and warranty ratings | Layers separating at the edge |
Owens Corning makes its own weathering-grade asphalt through its Trumbull Asphalt plants, which it calls the leading supplier of that asphalt to the roofing industry.
How the line runs, step by step
- Mat. Glass fibers are formed into a continuous sheet. Owens Corning notes that fiberglass replaced the older organic felt because it does not absorb moisture.
- Asphalt coating. The mat runs through hot asphalt that coats both faces and seals the glass fibers in.
- Granules. Granules drop onto the hot top surface and are pressed in while the asphalt is soft. Some lines blend in algae-resistant granules to fight dark streaks.
- Sealant. A strip of adhesive is applied where the next course will sit. On a roof, the sun softens it and it bonds the shingles together.
- Cut or laminate. Single sheets are cut into 3-tab shingles. For architectural shingles, a second coated layer is bonded underneath, which creates the shadow lines.
- Cool, stack and bundle. Shingles are cooled, stacked and wrapped. The wrapper carries the product name, color, plant and installation instructions, which matter later for warranty and code questions.
Why construction matters in Colorado Springs
Two layers fail first on Front Range roofs: granules and sealant.
- Granules and sun. Colorado Springs sits high and gets strong sun, so bare asphalt ages fast. Granule loss from hail is the first thing an inspector looks for, because it exposes the asphalt to UV. Our composition shingle damage guide shows what that looks like from the ground.
- Sealant and wind. The National Weather Service warns that winds of 60 to near 100 mph can occur near the foothills, including around Colorado Springs and Denver. A sealant strip that never bonded, often from a cold-weather install, is the usual reason tabs lift. See installing asphalt shingles in winter.
- Layers and ratings. The extra layer in a laminate is why Owens Corning rates Oakridge for 110 mph (130 mph with six nails and its starter and hip and ridge), while Supreme 3-tab carries a 60 mph rating. Our page on why we steer people away from 3-tab covers when 3-tab still makes sense.
What this means when you compare bids
The shingle is one layer of a larger system. Underlayment, ice barrier, starter, flashing, vents and ridge cap decide whether the shingle can do its job. Our guide to what a roofing system includes turns that into a checklist for comparing estimates, and Owens Corning shingle lines compared explains the products we install.
To compare specific shingle lines and the layers under them, see our shingle and product guides; for how codes and contractor credentials shape the install, see our roofing industry guides.
Wondering whether your shingles are near the end? Read when an asphalt roof needs replacement, or let us look. Integrity Roofing and Painting is veteran-owned and family-run since 1990, an Owens Corning Platinum Preferred contractor with 650+ Google reviews. Call (719) 488-2800, book a free Colorado Springs roof inspection, or see asphalt shingle roofing in Colorado Springs.
Sources: Owens Corning, How are shingles made? (shingle layers, fiberglass mat, laminated construction, Trumbull Asphalt; confirmed through Owens Corning's search index because the page now redirects), Supreme and Oakridge product pages; National Weather Service Denver/Boulder, High Wind Safety.
