Drone survey in Crediton

Crediton sits in the Creedy valley among some of the most productive farmland in Devon, and the surrounding parishes are full of farmhouses, barn conversions and working agricultural buildings. Corrugated metal on farm buildings is as common a covering here as slate is in the town.

Agricultural roofs are a good case for flying. The spans are large, the coverings are old, the buildings are frequently in use below, and getting a person safely onto a corrugated roof is a job in itself. A morning in the air covers a whole yard of buildings and produces a record of each.

The town is open to Atlantic weather from the west with little shelter, and the valley traps damp air. That combination is hard on thatch ridges in particular, because a ridge is the part of a thatched roof that wears first and the part that keeps the rest of it dry.

North-facing slate suffers the same way for a different reason: it never dries out properly, so growth establishes and holds water in the laps. Both problems are visible from above and effectively invisible from below.

The long Georgian and Victorian high street carries Devon slate and stone tile, with cob and thatch cottages in the surrounding lanes and modern estates on the valley sides. Stone tile is heavy and its condition depends as much on the structure holding it as on the tiles themselves.

Where a stone tile roof has started to move, the geometry gives it away before any individual tile does. A photograph square onto the slope makes a sag or a spread obvious in a way that standing in the lane does not.

There is space here. Farmyards, fields, gardens and a valley with room in it. Take off positions are rarely a problem and standoff distances are comfortable, which makes for good photographs.

The main constraint is wind off the open west, and livestock, which flights are planned around as a matter of course rather than as an afterthought.

Barn conversion is common around Crediton, and a building part way through that process is a specific kind of survey subject. There is usually original fabric, recent structural work and new covering meeting each other, often under a planning condition about how the result should look.

A dated aerial record during the works is useful for two reasons. It shows the condition of what was there before, which matters if a dispute arises later, and it evidences what was done at each stage for anybody who has to sign the work off.

For EX17 owners further out, the same visit usually takes in the farmhouse and the range of buildings around it, which is a more sensible unit than one roof at a time.