Drone roof survey in Dawlish

Dawlish is really two places for roofing purposes. The old town sits in a narrow valley around the Dawlish Water and The Lawn, sheltered on both sides, with Regency and Victorian terraces and a good deal of render and parapet detailing.

Above and either side of it, on the cliff tops towards Dawlish Warren and out past the golf course, is a large estate of post-war bungalows and modern housing that takes wind with nothing at all in the way. The difference in exposure over a few hundred metres is dramatic.

Anyone assessing a Dawlish roof needs to know which of the two they are looking at, because the failure modes barely overlap.

Bungalows on exposed cliff top ground combine two things that do not go together: shallow pitches and severe wind. A shallow pitch already relies on every lap doing its job, and wind pressure pushing rain back up the slope is exactly the load it copes with least well.

Ridge and verge details take the brunt. Mortar bedded ridges on these estates lose tiles most winters, and once one goes the neighbouring ones are working loose within a season. Verges at the gable are the other common casualty.

Flat felt roofs over extensions, garages and conservatories are widespread here and they are the third recurring issue, because uplift on a flat covering at the edge is where a membrane starts to peel.

Dawlish Warren, the sand spit and nature reserve at the mouth of the estuary, sits below the same cliff top ground and marks where the exposed upper town gives way to flatter, more sheltered land around the golf course. Roofs closer to the Warren get some shelter from the dunes on a westerly, but nothing at all on the south-easterly gales that do the real damage, so the shelter is partial rather than reliable and should never be assumed without checking which direction a particular storm is coming from.

The railway runs along the sea wall at the foot of the town, and in south-easterly storms the wall is overtopped and sea water is thrown across the line and into the front of the town. Salt reaches everything in the lower town in those conditions.

Red sandstone cliffs either side add another element: the stone is soft and erodes, and the dust and grit from it finds its way into gutters and valleys along with everything else.

The valley itself keeps the air damp, so even the sheltered part of the town has heavy organic growth on shaded slopes and slow drying after rain.

The railway itself is part of the town's roofing story in an indirect way: the line has been closed by storm damage to the sea wall more than once in the last decade, and each closure is a reminder of how much force the town absorbs in a bad south-easterly. A roof that has stood through one of those storms without an inspection is not a roof that has been proven sound, only a roof that has not yet been looked at properly.