Clay tile vs concrete tile roofs: telling them apart in aerial imagery
An applicant's ACORD form says "tile roof." It doesn't say which kind. That gap matters more than it looks: clay and concrete tile carry different weight loads, different wind uplift ratings, different replacement costs per square, and in some books, different appetite entirely. A roof covering field that just says "tile" is underwriting on half the picture.
From the ground, telling clay from concrete is usually easy. A contractor walks the roof, taps a tile, checks the edge for the fired-clay color-through versus a painted or dyed concrete surface. Underwriters don't get that visit before binding. What they get, if anything, is a photo attached to the application or a Google Street View frame from three years ago. Aerial and satellite imagery, when the resolution supports it, gives a more current and more consistent read than either.
What shows up from overhead
Tile profile is the strongest signal at VHR resolution. Clay tile, especially barrel or Spanish profile, casts a repeating shadow pattern along each row, a series of short dark arcs running the length of the course. That curvature is a manufacturing constant; clay tile is extruded or pressed into a round or S-shaped mold and it holds that shape for the life of the roof. Concrete tile comes in both low-profile (flat slab) and high-profile (barrel-imitation) styles, so profile alone doesn't settle it. But a flat concrete tile roof reads almost shadowless from directly overhead, with the only texture coming from the overlap lines between courses.
Color is the second cue, and it's the one that misleads people fastest. Clay tile color runs through the material, so fading from UV and weather tends to be even across a roof plane, maybe lighter at the ridge where sun exposure is highest, but consistent in hue. Concrete tile is usually surface-coated or integrally colored with a cement-based pigment, and that coating wears unevenly. A concrete tile roof ten or fifteen years old often shows blotching, streaking below vents and chimneys, and a chalky lightening where the coating has worn thin. If a "uniform terracotta" roof in the image actually shows patchy fading along drainage paths, that's concrete mimicking clay, not clay itself.
Surface texture is the third, and it needs the higher end of VHR resolution to read reliably. Clay tile has a smoother, almost glazed look in bright sun, sometimes with visible kiln variation between individual tiles. Concrete tile has a slightly matte, aggregate-flecked surface, consistent tile to tile since the molds don't carry the variation clay firing does.
Where this changes the underwriting file
None of these cues replace a roof inspection when the exposure or the limit justifies one. What they do is narrow the question before the file gets there. A roof covering field populated from the application alone is one data point, and it's the one point in the file the insurer didn't independently check. A roof covering read from current imagery, even a probable-material call rather than a certainty, gives underwriting something to weigh against what the applicant wrote, and it flags the files where the two don't match, which is exactly where you want a closer look before binding rather than after a hail claim.
That's the broader gap Property Characteristics was built to close: a structured, per-address record of roof geometry, material, storey count and visible site condition pulled from current VHR imagery, so the roof covering line in the file reflects what's on the house instead of what got typed into a form months or years ago.
If clay-vs-concrete calls keep coming down to a guess from a stale photo, it may be worth seeing what a current image of the roof shows.