Natural slate roofing

Slate is a remarkable roofing material and the reason so many of this town's roofs are still original. It does not absorb water, it does not degrade in frost, and it is dimensionally stable — the failures in a hundred-year-old slate roof are almost never the slate. They are the nails, the battens or the detailing.

The slate on the silk-era terraces here is overwhelmingly Welsh, which arrived in quantity once the railways made it cheap in the second half of the nineteenth century. It is thin, light, splits very finely and is genuinely capable of a century or more in service. Spanish slate is what most new work uses today and good Spanish slate is excellent; it is simply thicker and different in colour, which is why dropping one into an old Welsh roof shows.

Getting slate right is mostly about three numbers. The headlap — how far each slate covers the one two courses below — has to increase as the pitch falls and as exposure rises, and getting it wrong lets driven rain past even though every slate is intact. The gauge, which is the batten spacing that produces that headlap. And the nail: two nails per slate, in the right position, in a metal that will not corrode. Copper and stainless outlive the alternatives by a wide margin, and after the last century's experience with iron there is no good argument for anything else.

That local housing mix is worth being specific about, because it decides what work a house is likely to need. VOA council tax stock data for 2024 puts central Macclesfield at 54.1% pre-1919 against an England average of 20.1%, while Tytherington is 1.5% and Weston is 80.3% built between 1945 and 1982. So slate work concentrates heavily in the centre and the older villages, and the estates on the edges are almost entirely a tile conversation.

The other Macclesfield-specific factor is access. The Macclesfield Character Assessment describes the silk-era workers' cottages and three-storey weavers' garrets as built hard up against the pavement edge — which means there is often no private ground at the front to stand a scaffold on. A scaffold over the footway needs a licence from Cheshire East as highway authority, and that has to be arranged and paid for before the work starts. It belongs in the quote.

Reclaimed slate deserves its own note. It is not a compromise: on a repair or a partial strip it is frequently the better material because it matches, and on a conservation-area roof it may be what the planners expect. Good salvage suppliers grade and sort, and the slates coming off your own roof are always the best match available.