Shurdington roofs, specifically
Why Shurdington roofs green up faster than the open ground around them.
Shurdington sits in a narrow strip between Gloucester and Cheltenham, right at the foot of the Cotswold escarpment below Leckhampton Hill and the Devil's Chimney. That position is lovely to look at and hard on roofs. Cool, damp air and rainwater drain down off the slope and settle over the village, the hill throws long afternoon shade across the eastern side, and the whole place sits low enough to hold humidity that higher, more exposed ground sheds. Moisture and shade are exactly what moss, lichen and gloeocapsa algae feed on — so a roof here will carry noticeably more growth than an identical house out on open farmland a couple of miles away.
You see it most clearly on the older, tree-lined plots. The lanes that run up towards the escarpment — Crippetts Lane, Greenway Lane and the network of older Greenway properties — are semi-rural, hedged and heavily shaded, and the stone and slate cottages along them hold damp far longer than modern materials. Add the leaf-fall from the mature trees that line so much of the village, around the Bell Inn, the recreation ground and the green by St Paul's, and you get north-facing pitches that barely dry out between October and April. By the time someone calls us, a roof like that is usually a thick mat of moss sitting in the laps with the gutters already choked with what's washed down.
Out on the newer parts of the village it's a different roof but the same problem. The estates strung along the Shurdington Road and the more recent Greenway Chase development are mostly modern concrete interlocking tile. Those tiles are textured, which gives spores something to grip, so even fairly young roofs mat up under this escarpment microclimate — we lift the bulk off by hand from a tower or roof ladder before any biocide goes on. Whether it's a period cottage near the church or a twenty-year-old semi off the main road, the cause is the same: damp air draining off the Cotswold edge, and not enough sun to dry the tiles out. The fix is the same too.
One thing that's specific to Shurdington is how split the village is. Great Shurdington and Little Shurdington, the old core around St Paul's, the ribbon of houses along the A46 and the modern closes behind it all sit close together but carry very different roofs — and the trees and the slope mean the damp doesn't fall evenly. A house tucked under the hill on the eastern side will green up faster than one of the open-plot bungalows out towards Badgeworth. It's why we survey each property rather than quoting a roof we haven't seen: in a village this varied, the right method changes from one street to the next, and on the older stone and slate we won't go anywhere near it with high pressure.