Drone roof survey in Honiton

Honiton's high street was rebuilt after the eighteenth century fires, which is why it is so consistent, and that consistency has a consequence people underestimate. What looks like a row of individual buildings is often a continuous run of roof over shared party walls, with each owner responsible for a slice of a single structure.

Water does not respect that boundary. A blocked valley or a failed flashing on one property regularly shows up as a damp patch two doors down, and sorting out who pays for what has usually already turned into an argument by the time anyone rings.

A flown survey covers the whole run in one flight, which is why it is worth doing here even when only one owner has a problem. Seeing the neighbouring roof planes is often the only way to work out where the water is actually entering.

Honiton's lace making history left more than a museum behind it. Several of the older buildings along the high street were built or extended for the trade, with roof spaces that were once used for drying and storage and carry irregular later alterations as a result. Those alterations are exactly where an unrecorded change in construction meets weatherproofing that was never designed for it.

The Otter valley at Honiton holds fog. Through autumn and winter the town can sit under it for days while the Blackdown Hills above are in sunshine, and the practical effect on roofs is that they do not dry out.

Persistent wetting is what drives organic growth, and organic growth is what turns a functioning valley into a blockage and packs the head lap of a slate until water tracks sideways instead of down. On north-facing slopes in the town centre it is common to find moss deep enough to hold standing water.

It also works on mortar. Lime and cement bedding that stays wet through the winter and then freezes is being taken apart slowly, and on the ridge of a Georgian roof that is a fifteen year process that nobody watches.

The Blackdown Hills rise steeply north and east of the town, and weather coming over them hits the northern edge of Honiton and the outlying hamlets harder than the sheltered high street. Properties up towards Dumpdon and out along the ridge roads take real wind.

A lot of that outlying stock is cob and thatch, or slate on old rubble stone walls with very little in the way of modern underlay. Those roofs perform well when maintained and fail comprehensively when they are not, and the failure usually starts at a detail nobody can see: the thatch ridge, the junction with a later extension, or the point where an old chimney meets the slope.

Access out there is the usual rural story of narrow lanes and soft ground, which is exactly the situation a flown survey handles well.