Can drone roof inspections be used to monitor roof condition over time?

One survey tells you condition today. Two tell you the rate of change, which is what you actually need to plan: whether bedding is deteriorating slowly or quickly, whether slipped coverings are isolated or a spreading pattern, whether growth is advancing.

Rate of change is the difference between budgeting for renewal in eight years and discovering you needed it two years ago.

A baseline survey with imagery of every elevation from recorded positions. Repeat surveys at an interval suited to the roof — annually for older or exposed roofs, every two or three years for sound ones. Additional surveys after severe weather. A comparison report each time noting what has changed.

Records held so the sequence remains usable, and priorities updated at each round.

Older and heritage roofs where deterioration is gradual and materials matter. Tall or difficult buildings where nobody can see the roof otherwise. Commercial and multi-occupancy buildings where roof spending needs to be justified and planned. Portfolios where several roofs compete for the same budget.

In each case documented change is what makes a case for expenditure defensible.

Physical inspection of fixings, roof space checks and moisture testing on flat roofs. A sensible programme combines regular imagery with periodic physical inspection rather than relying on one alone.

Comparison only works if each survey covers the same ground in a similar way: the same elevations, similar viewpoints, and imagery clear enough to set against the previous set. A change of contractor between rounds is not a problem provided the new survey is briefed on what to match.

Keeping every round's report and imagery together, rather than only the most recent one, is what lets a genuine trend be shown rather than a single before-and-after snapshot that could be explained several ways.