Roof repairs diagnosed properly, fixed once

Most roof failures we attend started as a small defect that nobody could see from the street: a slipped slate, a cracked cement fillet, a blocked parapet outlet. GEM's roofing teams inspect properly, with access equipment or drone survey where appropriate, and repair the actual defect rather than chasing symptoms through the ceiling below.

Why intermittent leaks are detailing failures

A leak that only appears in heavy or wind-driven rain is usually a detailing failure (flashings, junctions, outlets) rather than the roof covering itself. Water also travels: it can enter at a parapet, run along a purlin and appear two rooms away, which is why chasing the stain instead of the entry point wastes money. We survey the suspect zone, test where practical and evidence the defect with photographs before quoting, and where roof access is expensive we fly a drone first so the survey cost stays proportionate to the repair.

The roofs London actually has

We work across pitched slate and tile, flat roofs in felt, GRP and single-ply, mansards, parapets, valley gutters and the leadwork of period terraces. Each covering fails in its own way: nail sickness on Victorian slate, blistered felt on post-war extensions, split lead on bay tops, and the repair method has to match the covering rather than defaulting to a bucket of bitumen. When replacement is genuinely due, we scope, scaffold and programme the work with fixed staged pricing and photographic progress reporting throughout.

Chimneys are the most neglected structure on a London roofline. Cracked flaunching lets water into the stack, frost does the rest, and an abandoned chimney quietly damps the bedroom below through its open flue. We repoint, re-flaunch, cap redundant pots with ventilated caps and renew the lead soakers and flashings where stack meets slope, which is where most chimney-adjacent leaks actually start.

Gutters and roofline, before the storm

Gutter clearance, repair and roofline maintenance are handled as planned works for subscribers, ideally before autumn rather than after the first storm. Annual clearance suits most properties; twice a year where trees overhang. Blocked parapet and valley outlets deserve particular attention on London terraces because the overflow path is often straight into the building. Rotten fascias and soffits are replaced rather than overclad where the timber has gone, since capping wet timber seals the decay in with the ventilation out.