Asphalt shingle vs. wood shake: telling roof coverings apart in imagery
An application comes in listing "composition shingle" for the roof covering. Maybe that's accurate. Maybe the homeowner wrote what they remembered from ten years ago, or the agent filled it in from a prior term without checking. Either way, roof covering drives your rate, your wind/hail deductible logic, and in some states your eligibility for coverage at all. Wood shake carries different fire and weathering risk than asphalt composition, and a lot of underwriting guidelines treat the two completely differently. If the only thing standing between "trust the form" and "verify the roof" is a site inspection nobody has time to schedule before binding, imagery is worth a look.
What follows is what to look for when you pull up a rooftop in VHR imagery, and where the two materials get hard to tell apart.
What asphalt shingle looks like from above
Composition shingle roofs read as a fairly uniform surface with a fine, repeating horizontal pattern, the shingle courses stacked in even rows. In RGB imagery at sub-meter resolution, that pattern shows up as subtle banding rather than individual tabs, but the banding is consistent across the whole slope. Color tends toward gray, brown, or charcoal, and it's flat and even, no strong texture variation from one square foot to the next. Edges at the ridge and hips are clean, straight lines. If you zoom into a residential subdivision built in the same decade, you'll usually see the same shingle pattern repeat house after house, because the roofer used the same product on the whole phase.
Granule loss on an older asphalt roof shows up as lighter patches or streaking, usually concentrated on south- and west-facing slopes where sun exposure is worst. That's a different signal than material identification, but it's worth noting in the same pass since it also speaks to roof condition and remaining useful life.
What wood shake looks like from above
Wood shake has a rougher, more irregular surface texture even at a distance. Individual shakes are thicker than shingle tabs, with ragged edges and uneven spacing, so the roof plane doesn't read as flat. You'll often see mottled, uneven coloring, grays and browns rather than one consistent tone, because wood weathers unevenly and shakes cup and curl over time in a way manufactured shingle doesn't. The ridge line on a shake roof tends to look less crisp; shake ridge caps are bulkier and cast more shadow than a shingle ridge cap does, which is one of the more reliable tells in oblique or early/late-day imagery where shadow length is longer.
Age matters a lot here. New shake is lighter in color and evenly toned, so it can briefly look closer to asphalt than you'd expect. Weathered shake, which is most of what's on roofs in the field, is where the texture and color irregularity become obvious.
Where imagery alone runs into trouble
Tile and slate can throw false positives for shake on first glance, since both have more surface relief than flat composition shingle. Shadow angle, time of year, and sun position all change how much texture an image actually resolves, so the same roof can look different depending on when the capture happened. And at the lower end of acceptable imagery resolution, fine material texture simply doesn't resolve at all; you need imagery sharp enough to show individual course lines or shake edges, not just the roof outline and ridge lines. This is a case where resolution matters more than it does for something like counting stories or flagging a pool.
None of this replaces a field inspection when a file is borderline or the exposure is large enough to warrant one. What it does is let you triage: most files, the roof reads clearly as one or the other, and you can move on without a truck roll. The ambiguous ones get flagged for the adjuster or inspector to confirm, instead of every file getting the same manual review regardless of risk.
That's the practical use case behind Property Characteristics: pulling roof geometry, material, story count, and other visible site features from VHR imagery into one structured record per address, before you bind, so the file in front of you reflects what the roof looks like rather than what got typed into a form. If roof covering verification is slowing down your new business pipeline, it's worth seeing what that record looks like for your own book.