The short answer
Usually the details, not the covering. On long terraces and blocks, valleys, chimney flashings, gutters and ridge bedding give up before tiles or slates do, and a fault in one place often shows up as damp in a neighbour's ceiling. Fixing those points in one visit is quicker and cheaper than returning for each leak.
Barrack-era and later terraces in Tidworth were built to a pattern, and the same weaknesses repeat from house to house. That helps, because it means we know where to look.
Q1.1Why do chimney flashings and valleys leak?
The metal around a chimney is the busiest joint on the roof. Lead moves in the heat and cold, work-hardens and splits, and the mortar fillet holding it into the brickwork loosens. A valley, the trough between two meeting slopes, has a lining that takes the water from both, so a small crack there can soak a ceiling quickly. We open up the junction, replace what has failed and re-dress the lead so it can move without tearing. Our roof repairs page shows how we work.
Q1.2What about gutters on a long run?
Long gutters need a gentle, even fall towards the downpipes. When a bracket slips or a joint opens, water pools, overflows and runs down the wall, staining brick and soaking the eaves. A repair is often as simple as re-aligning a section and renewing a seal, though old cast or pressed-steel gutters sometimes need replacing by the length.
The loft tells its own story too. Daylight showing through the roof, dark tide-marks on the rafters, soggy insulation and rusted nail tips poking through the underlay are all signs we note from inside, because they reveal the route water has taken long before a ceiling stain appears. A roof with those signs in only one corner is a repair job, and we write it up that way. On a terrace, it helps to coordinate with neighbours. A shared repair means one scaffold and one visit, so the cost of access is spread across the row rather than paid several times.
Each fault is photographed where we find it, so the quote we write afterwards can show you exactly what we saw.