Drone surveys in Okehampton, flown by the surveyor who writes them

Okehampton sits at the northern foot of Dartmoor where the East and West Okement meet, with the high moor and Yes Tor rising immediately to the south. It is about forty minutes from Exeter on the A30 and, weather aside, an easy town to work in.

The weather is not an aside though. Dartmoor forces Atlantic air upwards right on the doorstep, so rainfall is high, driving rain is frequent, and roofs stay wet for long periods. This is one of the wettest and windiest towns in the coverage and the survey work reflects it.

Prolonged saturation is a different failure mechanism from storm damage and it produces different findings. Slate that never dries out delaminates from the tail upwards. Mortar bedding at ridge and verge loses its bond gradually rather than in a single event. Timber under a covering stays at a moisture content where rot is possible for months at a time. Organic growth establishes thickly and then holds yet more water against the covering.

The practical upshot for a survey here is that the findings tend to be systemic rather than local. Where a Dawlish roof has three tiles missing from one gale, an Okehampton roof has an even deterioration across every north facing slope. That changes the conversation from repair to planning, and it is worth having the photographic evidence when making that case to a client, a trustee or an insurer.

Granite bedded ridges are a local detail worth knowing. They are heavy, they last, and when the bedding does fail the units are substantial enough to be a real hazard, so they are photographed closely as a matter of course.

The centre is granite and slate, with Victorian terraces and a large stock of post-war housing behind it. Beyond the town the parishes carry scattered moorland farms and longhouses, and those generate a different sort of enquiry: corrugated metal on farm buildings, long low ranges, and roofs that nobody has been on in twenty years.

Corrugated sheet reads well from the air. Corrosion at the fixings, sheets that have worked loose at the laps, translucent panels that have gone brittle, and the state of the ridge capping are all visible in a single pass. For a farm with several buildings, one flight covers the lot and gives an order of priority.

Longhouses and moorland farmhouses are the more interesting case: old, often listed, frequently altered, and standing in fully exposed positions with nothing between them and the moor.

Weather on the moor edge changes fast and it changes locally. A clear morning in Exeter means very little about what is happening at the foot of Yes Tor forty minutes later, so flights here are planned with the local forecast and with a willingness to abandon.

Open ground and high terrain also affect the radio link and the visual line of sight, both of which are planned around conservatively. Meldon Viaduct, the castle and the National Park boundary are the local landmarks, and the Park itself is treated with the care any protected landscape deserves when planning where an aircraft goes.