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

Barnstaple is a little over an hour from Exeter, up the A361 across the middle of the county. It is one of the longer trips on this list and it is normally planned as such: a North Devon day rather than a quick visit, often taking in Bideford or the surrounding parishes at the same time.

None of that changes the price. Travel is inside the fixed figure whether the address is in Topsham or Ilfracombe. What it changes is the diary, so a little notice helps and pairing addresses helps more.

The town occupies low ground beside the river at the tidal limit of the Taw, with steep wooded slopes rising north towards Exmoor. Those two positions produce different survey jobs. Down by the water the issue is persistent damp and the age of the fabric. Up on the slopes at Newport and Sticklepath the Victorian terraces sit high enough to catch wind that the town centre never feels.

The Georgian and Victorian centre around the Pannier Market and Butchers Row is the part that most repays aerial work. Historic roofs packed tightly together, with valleys and abutments between buildings in different ownerships, and no practical way to see any of it without either scaffolding a listed frontage or flying.

The Taw estuary points west, and weather comes up it from the Atlantic with very little to break it. Rainfall is high and, more importantly for a roof, the wetting is prolonged. It is not the intensity of a single storm that finishes a slate covering here; it is that shaded slopes barely get a chance to dry out between one system and the next.

Prolonged wetting is the main agent of decay on the shaded slopes, and it shows in specific ways worth photographing: delaminating slate that has gone soft at the tail, nail sickness where the fixings have rusted through while the slate itself is sound, mortar bedding at ridge and verge that has lost its bond, and organic growth thick enough to hold water against the covering.

For a flight, west facing exposure means checking the wind properly rather than trusting the forecast for Exeter. The two are frequently different, and a survey booked on an Exeter forecast is one that gets rescheduled from the far end of the A361.

Large post-war estates and newer development at Roundswell and Anchorwood sit around the older core, mostly on concrete interlocking tile with some clay plain tile in the older parts. These are simpler surveys and they usually come up for a different reason: a leak nobody can place, or a landlord wanting a condition record before a tenancy or a sale.

The trading estates carry large span industrial roofing, and the same logic applies here as anywhere else in Devon. From the ground you can see one elevation. From twenty metres up you can see the whole covering, the gutters, the rooflights and the plant in one pass, and decide what is worth spending money on.