Roof leak detection in Tavistock

Tavistock's centre is a remarkable, deliberately planned Victorian town built in green Hurdwick stone on mining wealth, with Georgian survivals, terraced miners' cottages in the surrounding villages, and modern estates on the fringes. Natural slate and Delabole slate dominate, with stone-bedded ridges on the older buildings and concrete tile on the later housing.

The mining-era architecture built notably tall stone chimneys as a matter of civic pride as much as function, and those stacks, along with steep siting across the town, mean wind loading on chimneys is a live, specific concern here rather than a background worry.

Okehampton, Plymouth, Launceston and Ivybridge are all within reach of the same trip, and each of those towns has its own page here, written around its own construction rather than Tavistock's Hurdwick stone and mining-era chimneys assumed to apply everywhere on Dartmoor's edge.

Tavistock sits in the Tavy valley on Dartmoor's western edge, with the moor rising immediately east and the Tamar valley falling away west towards Cornwall, a position that catches rain from two directions: off the moor and up the Tamar on the prevailing south-westerly. The result is a persistently wet town where a poorly bedded stack or a silted valley has plenty of water to work with.

A tall stone stack with a loose flashing at its base is a classic Tavistock fault, one that a visual pass alone often cannot resolve because the lifted lead is a matter of millimetres from most ground-level or even aerial visual angles, but which a thermal pass, reading the damp masonry around the base against the dry stonework above, tends to isolate clearly.

The PL19 postcode area sits on the Devon side of the Tamar, close enough to the Cornish border that weather arriving from the west reaches Tavistock before it reaches most of the rest of this site's Devon coverage.

Getting a scaffold safely around a tall Hurdwick stone stack on a steep Tavistock site is a properly specialist, expensive job, and a drone's standoff distance sidesteps most of that difficulty entirely for the diagnostic stage.

The Cornwall and West Devon Mining World Heritage Site designation covering much of the wider area is also worth knowing before any repair work is planned, since it can affect what can be done once the leak is found, which makes establishing the fault clearly, in writing, before work starts even more valuable here than usual.

The Pannier Market building itself, and the terraced miners' cottages in the villages just outside town, both carry roofs shaped by the same mining-era construction methods as the grander Hurdwick stone buildings in the centre. A trace covers whichever of those a job turns out to be at the same fixed price, agreed before the visit rather than adjusted once the aircraft is already in the air.