Roofing in Beacon Hill

Ridge, hips and verges. Most of Beacon Hill went up between the late 1960s and the early 1980s, and those roofs carry concrete interlocking tile with the ridge, hips and gable verges bedded in sand and cement. Mortar bedding has a working life and forty odd years is about it: it cracks, water runs down the back of the ridge tile, and eventually a cap lifts in a gale. We take it off and convert to a dry fix system screwed and clipped over a ventilated roll, the mechanical fixing BS 5534 expects, which vents the roof space along the ridge while it is at it.

The eaves course of underlay. The bitumen felt laid under those roofs is brittle now. It tears first where it laps into the gutter, the one place it has to be sound, so water runs behind the fascia instead of into it. A wet fascia and soffit with a dry loft is nearly always this, and eaves protection trays and a new felt support put it right without stripping the slope.

Repairs are slipped, cracked and missing tiles, storm damage, and leaks traced to where water genuinely enters. When the nails, battens and underlay have perished together the covering comes off, soft rafter feet are replaced, and it goes back on breathable membrane and treated battens with a matched tile.

Flat roofs over the integral garages, extensions and porches are inspected deck first, and those abutments are often sealed up with mastic by somebody in a hurry, which is a leak with a date on it. A fair share of the leaks we attend are a gutter running over or a downpipe discharging into thin air, and on ground that shrinks and swells where that water goes matters. With the roof open, insulation and eaves ventilation are cheap, and Approved Document L sets the standard a renovated roof must reach.

No rate per square metre: the area is the easiest thing to measure and the least useful thing to know. Bungalows and chalets here often come off a tower, and the two storey estate houses want a scaffold, which is usually straightforward because the drives are wide. How long it stands matters as much as its size, and the work at height rules are why the platform is a priced line.

Chimneys, valleys and abutments are priced one at a time. Ask whether the scaffold is in the price, whether battens and membrane are renewed or covered over, and who pays for the skip.

The ground under Beacon Hill is cohesive and it shrinks and swells with the weather. That turns rainwater into a structural question rather than only a damp one, and it changes what we do at the bottom of a downpipe rather than at the top of the roof. A downpipe emptying onto a border, a gully that has silted up, or a soakaway sitting too close to the wall all put repeated wetting and drying into the ground beside a foundation, and that is the one thing this ground does not take well.

So when we price roofing work here we follow every downpipe to see where it actually goes, and we say so if the answer is nowhere. Approved Document H is the standard for getting roof water clear of a building. It is cheap to put right while the scaffold is up and expensive to leave.