Painters and decorators in Four Lanes, up on the hill above Redruth

Height, mostly. Four Lanes sits on the high ground south of Carn Brea, on the road from Redruth towards Helston, and it is often sitting in cloud or taking the full wind while the towns below are dry. Walls up here are wetted more often, dry out more slowly and get less sun in the process, so a granite cottage that would be fine a few hundred feet lower spends more of the year damp.

The other half of the answer is the wall itself. The old cottages and terraces in the village are solid granite or rubble, built for mining families, and they were never meant to be sealed. Moisture comes in through the stone and the pointing and is supposed to go back out the same way. Where a cement render, a plastic-type masonry paint or a vinyl emulsion inside has closed that route off, the water stays in the wall and shows itself as dark patches at low level, salts blooming through the paint and plaster that goes soft.

So we do not simply paint over it. On a cottage like this we look first at the obvious causes, a blocked gutter, ground built up against the wall, a failed sill, and then at what the wall is coated in. Once the wall can dry, a breathable masonry paint outside and a breathable finish over the lime plaster inside give it the chance to carry on breathing. If the render is the problem, we will say so, because paint will not fix it.

For the same reason. Exposure. The south-westerlies come across the open ground with nothing to slow them, the rain arrives sideways and the cloud keeps the surface wet long after the shower has passed. A coating that has to cope with that on a west- or south-facing gable will always be renewed sooner than the same tin on a sheltered wall. It fails at the edges first, round windows, along the top of the render and on any painted timber, then lifts in sheets once water gets behind it.

Much of Four Lanes is not old cottage at all. There is a great deal of later housing, bungalows from the middle of the last century onward, semis and infill along the lanes, most of it in cement render or pebbledash with timber or uPVC windows and an attached garage. These are quicker to reach, a bungalow can usually be done from ladders and a short tower, but dash on an exposed elevation drinks paint and goes chalky, and that chalk has to be washed off and bound before a new coat will hold.

Preparation and timing are what make a coating last on this hill. Wash-down, cracks opened and filled, hollow render cut out, chalky paint stabilised, then two coats of a proper masonry paint, with bare timber primed and the coats rebuilt on sills, fascias and doors. And it is done when the walls are dry: the exterior season in Four Lanes starts later and finishes earlier than it does in Redruth, so the settled weeks from late spring to early autumn go quickly and are worth booking ahead.

Interior work here splits along the same line. In the cottages and terraces, and the chapels that have been turned into homes, it is uneven lime plaster, deep window reveals, beams and boarded ceilings, and years of paint over paint. We fill and sand, seal what needs sealing and use finishes the old walls can cope with, and a room is often as much repair as it is colour. In the bungalows it is more usually a whole house brought back to a clean neutral, a kitchen or bathroom finished off after the fitters, or the hall and living room that get the most wear.

Nothing is priced from a photo up here. Inside, we want to see the state of the walls and woodwork, any paper to strip and how much furniture there is, which set the price far more than the size of the rooms. On an exterior we walk round every elevation, check the render by hand, note where the ground slopes and where the wind has been getting at the timber. The quote then sets out what it covers, how much preparation has been allowed for and how many coats, and if the render turns out worse under the old paint than it looked from the road, that is a conversation and a revised figure, not a surprise.