Roofing & RepointingSpecialists inDoncaster

Older pantile roofs were often finished with a mortar torching applied under the tiles from inside the loft, sealing the gaps between the nibs. Over decades that torching cracks and falls away, and once it has gone the roof has no secondary defence against driven rain.

The symptom is usually a fine trickle of water or a patch of damp felt in the loft during heavy rain, with no single obviously broken tile to point to. It needs someone in the loft with a torch as much as someone on the roof.

A lot of Armthorpe and Wheatley's terraced rows have had the same pantile roof patched repeatedly since it was laid. Individual tiles get replaced, but the underlying bedding, battens and fixings are never addressed.

At some point patching a roof like this costs more over a few years than a proper re-roof would have cost outright. We will tell you plainly when that point has been reached rather than sending someone back every winter for another small repair.

Doncaster has a huge number of single-storey rear extensions finished in felt, many decades old. Once the felt splits and the laps open, water tracks along the deck before appearing somewhere unexpected inside the house.

The other recurring fault is the join where the flat roof meets the main house wall, frequently a cement fillet rather than a proper lead or dressed upstand, which cracks and fails within a few years of being applied.

Bessacarr and Cantley's inter-war and post-war semis mostly carry concrete tile roofs with mortar-bedded ridges. That bedding is now reaching sixty or seventy years old in many cases, and cracks open a little more with each frost cycle.

Left alone, a failing ridge lets water into the roof space along the whole run, not just at one point, which is why it is worth addressing before it becomes a series of separate leaks.