What can a drone roof inspection actually see?

Coverings that have slipped, cracked, delaminated or gone. Ridge, hip and verge bedding that has cracked, washed out or come loose. Flashings that have lifted, corroded, split or been poorly formed. Valley linings, and how much debris they carry. Chimney brickwork, haunching and pots. Growth on the covering and in gutters. Ponding, blistering and debris on flat roofs.

It also sees relationships — how a stack meets a slope, where a shared valley runs — which photographs from the ground cannot convey.

A dark, damp-looking area may indicate water retention, shading or growth. A blister on a flat roof may contain water. A covering that looks aligned may still be loose. In each case imagery narrows the question and physical checking answers it.

A report should distinguish observation from inference, plainly.

Battens, underlay, decking, rafters, insulation, cavity conditions, and moisture inside a flat roof build-up. Nor can it test whether a nail still holds. Those need access, opening up, or moisture testing.

Nobody should present drone imagery as proof that concealed elements are sound.

Light, wind, rain and proximity restrictions. Overcast conditions are often better than bright sun, which throws hard shadows. Where conditions prevent adequate imagery of part of the roof, that should be stated rather than glossed over.

Photographs on their own can be misread by anyone without roofing experience: a shadow can look like a crack, and a genuine crack can be missed in a wide shot. That is why imagery should be paired with a written explanation of what each image shows, not left to speak for itself.

Ask specifically how a finding was reached where it is not obvious from the photograph — a competent surveyor can explain the reasoning, and a report worth relying on records that reasoning rather than a list of images with no commentary.

Coverage matters as much as sharpness. Ask for each elevation as a whole, then closer frames of the ridge, hips, verges, valleys, chimney junctions and any area connected to an internal symptom, so nothing is left to inference.

Ask too for the date on the imagery and for a note of anything that could not be captured, whether because of wind, light, tree cover or airspace restriction. A survey that states its gaps is far more useful than one that appears complete but quietly leaves an elevation out.